Most of these articles on Permafrost Cryonic Interment (PCI) are reprints (with minor revisions) of articles that appeared in CANADIAN CRYONICS NEWS. "My Arrangements for PCI" appeared at the beginning of 1989, and the frequency of appearance of these articles has diminished with time, as I have become more concerned with (1) cryonics and (2) understanding brain structure well enough that I can return to studying other preservation methods with some idea of WHAT structures need to be preserved.
My thinking has undergone much revision over time. Most significantly, I am very doubtful that even the most ideal North American permafrost burial (50 feet below the surface at Resolute Bay, occurring very shortly after death) would be adequate to preserve much memory and identity for 100 to 150 years. Permafrost temperatures may be adequate to preserve identity, however, if used as an adjunct to three other techniques: (1) Chemical preservation (2) Isolation from oxygen and (3) Dehydration.
I would even say that chemopreservation and dehydration (if they could be done properly) are far more important than the cool temperatures of permafrost. In fact, without dehydration, there is a high likelihood that annual freezing and thawing would have a "meat-grinder" effect. But dehydration could be very destructive to tissue that has not been chemically cross-linked. Even in that case, the time required to dehydrate a large organ is time during which high-temperature tissue degeneration is likely to occur. Moreover, rescue teams now exist to begin cryonics preservation, but no such teams can be found for chemical preservation and/or dehydration with permafrost burial.
I no longer have PCI as my primary preservation arrangement (although it is still a back-up), since I have had cryonics arrangements since 1990. I have been accused of hypocrisy because of this, but to me there is no hypocrisy. There is still work to be done before PCI can really be considered a feasible preservation option. I have done much of this work myself and will continue to do more. I note that even many seasoned cryonicists assess the probable success of liquid nitrogen suspension as no more than 20%, giving social forces as the most likely cause of failure. I too am apprehensive about social forces, and this provides much of my motivation behind wanting to see more development of PCI. The technical superiority of liquid nitrogen suspension counts for little if the chances of a thawing are large.
The creation of a low-cost cryonic alternative is definitely one of my reasons for wanting to develop PCI. Even if I am suspended in liquid nitrogen, the probability of my suspension succeeding will be better if social resentment does not exist that cryonics (and survival) is only for the rich. I am reluctant to admit to altruistic motives, but I must acknowledge that the thought of would-be immortalists rotting to death because of financial failure does wrench my heart. PCI also seems like a method which is well-suited for last-minute, non-member cases seeking cryonic preservation. It is terrible to have to turn someone away, and bad public relations. Finally, the vulnerability of cryonics organizations to prosecution, persecution and financial failure -- along with the dangers of political and environmental upheavals -- makes me think that the PCI option needs to be developed, even if only as a backup. And I believe that this is very much in the interest of all cryonicists.
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I have recently purchased a $25,000 life insurance policy naming the Cryonics Society of Canada (CSC) as beneficiary. A lawyer has drawn up a Last Will and Testament for me which directs that I be buried in the Canadian Arctic permafrost. The Will also names Douglas Quinn (or the President of the CSC) as the executor of my estate. For about 200 Canadian Dollars I have thereby become (to my knowledge) the world's first person to make advance arrangements for a permafrost cryonic interment.
I have desired immortality since I was a small child, and became
skeptical of the likelihood of achieving it by supernatural means
before puberty. I read The Immortalist
and The Prospect of
Immortality about 14 years ago. Before discussing my current cryonic
arrangements and plans, I want to say something about why it has taken
me so long to begin making any such arrangements.
Much of my life has been concerned with the issue of survival. Cryonics is but one of many techniques for surviving. Long-term survival requires prognostications of future development. In the past, my visions of the future have been far too grim for me to even consider cryonics. I did not believe mankind would still be in existence, much less continuing to progress technologically, a hundred years from now.
Nuclear proliferation shows only some sign of abatement. Currently less than ten nations possess nuclear weapons, but how many will have them in 10, 30 or 50 years? How many nations will feel impelled to use them? How long will it be before terrorists gain access to nuclear weapons? Technology will reduce the cost and complexity of nuclear weapons, increasing their availability to the point that conditions may well pose a true threat to the survival of mankind. It has not escaped my attention that all 3 American cryonic suspension facilities are located near primary nuclear strike zones (Los Angeles, Oakland and Detroit). The new suspension facility in New Zealand may seem more attractive because of this.
For many years I believed that deficit spending and fiscal irrationality on the part of major governments would send the world economy into a catastrophic collapse and depression, followed by civil strife and a breakdown of civilization. Extended power failures, riots and hyperinflation would not augur well for suspended patients. My instincts inclined me more towards wilderness survival skills than cryonics. An energy self-sufficient, self-maintaining cryocapsule in a fallout shelter in an Antarctic mountain would have been the only cryonic arrangement I would have accepted.
Social trends also give me mixed signals -- cause for both
optimism and pessimism. Computer technology continues its exponential
growth -- and its exponential contribution to productive capacity and
Life-extension, cryonics and most other areas of
science are making ongoing breakthroughs. But while the best aspects
of human civilization continue to grow, so do the worst. Drugs, crime
and homeless beggars continue to increase. An organism dies of
when unproductive (but reproductive) cells displace productive,
functional cells. Could there be such a thing as cancer of the human
social organism? Are there cures? Can they be found in time?
I have heard repeatedly that PCI would probably result in such poor preservation that reanimation is unlikely. My response to this is probably analogous to that of most cryonicists when they are told that reanimation from a suspension is unlikely. Although permafrost temperatures alone are inadequate to preserve biological structure, permafrost temperatures in conjunction with chemical preservation may well be adequate. I will grant that the repairs required by nanotechnology for a PCI will be more difficult than for a suspension, but I will not grant that reanimation (with memory) is improbable if no limits are placed on future technological growth.
The October 22, 1988 issue of New Scientist describes revival by Soviet scientists of a salamander that had been frozen in ice for 90 years. This may indicate that the deterioration that occurs in ordinary ice-freezing is far less than proponents of liquid-nitrogen temperatures imply (although I don't know how it was determined that the salamander had been frozen for 90 years). These proponents stress that liquid-nitrogen temperatures will maintain a body for thousands of years. But given the exponential implications of the doubling of biological knowledge every five years and the probability that the human genome will be mapped within ten years, it seems hard to believe that sufficient nanotechnology for reanimation will not be available within 100 years.
Robert Ettinger, founder of the cryonics movement, claims that "anything that has existed, can exist", meaning that it can exist again. For an unbounded optimist, this would mean that even a cremated person whose ashes have been scattered on the seas could conceivably be reconstructed. In this view, technology beyond our conception could gather enough evidence to reconstruct, atom-for-atom, human beings who vanished hundreds or thousands of years in the past. The technology for reconstruction will undoubtedly be nanotechnology. But other undreamed-of technologies may gather evidence and direct the activities of nanomachines. An atom-for-atom reconstruction would reconstruct memories. The memories of well-preserved persons who are reanimated may provide information for reanimating those who have been less well-preserved. Who can say what distinguishes reasonable from unreasonable optimism concerning technology of the far future?
Ettinger's Michigan-based Cryonics Institute offers suspensions for nearly a quarter of the cost of the California organizations, in part because Ettinger believes that costly perfusion procedures are unnecessary, relying more on future technology repair capabilities. Once again, I don't see that anyone is in a position to make such a judgement on future technical feasibility. There are cost/benefit tradeoffs, and the benefits are very difficult to calculate.
Aside from the fact that the damage from a PCI may be no less reparable than damage from a suspension (with or without cryoprotectants), there are other more notable benefits to a PCI. A PCI is far less vulnerable to nuclear strikes, wars, civil unrest, power failures and hyperinflation. Vulnerability to human error is minimized. Of most serious concern to me at present is the vulnerability of cryonics organizations to lawsuits and to conflicts with legal authorities. Also, erosion of capital due to financial mismanagement, unanticipated hyperinflation or the difficulty of maintaining trusts in a legal climate hostile to perpetuities does not seem improbable. Already two cryonics organizations, the Cryonics Society of New York and the Cryonics Society of California have allowed bodies to be thawed and buried conventionally.
A big lawsuit or a bad scrap with the law could easily spell disaster. And a disturbingly high percentage of suspension cases involve such incidents. If the use of cryonic suspension is to grow, these battles must be fought. I am torn between my desire to fight the good fight and my fear of perishing. I would feel better about suspension if I knew that I had a guaranteed fallback to a PCI, should cryonics organizations be rendered unable to provide maintenance.
The actual costs of a PCI may be under $5,000. At that price an
insurance policy might be unnecessary and the legal formalities are
not much more complicated than finding a co-operative Executor and
drawing a will. This compares very favorably to the mountain of
paperwork surrounding a cryonic suspension. And PCI is more palatable
for conventionally-minded people -- certainly much more so than
neurosuspension. PCI may be the answer for people who are desperately
seeking cryonic preservation for deceased loved ones who have not made
advance cryonic arrangements. PCI could make cryonics accessible to
"the masses", and thereby promote cryonics.
Proceeds from my $25,000 insurance policy should be more than adequate to cover the cost of a PCI, which is estimated to be well under $5,000. In my Will I have requested a gravestone no less than two feet high. I would also request that the burial site be surveyed and the results of the survey stored in a safety deposit box of the Cryonics Society of Canada.
The PCI of the Spring of 1988 occurred in the city of Inuvik, which is near the southern edge of the Beaufort Sea in the Arctic Ocean. The burial occurred in the city's established graveyard. Although the funeral director in Inuvik is considering establishing a separate graveyard for those interested in PCI, I have doubts about this location.
Scientists at the International Institute for Applied Systems Analysis (based in Vienna, Austria) are predicting that the world climate, which currently has an average temperature of about 15 degrees Celcius, will warm by 1.5 degrees Celcius in the next 35 years and by 5.5 degrees Celcius in the next 100 years. Warming near the poles is expected to be double the global average. A location currently on the edge of the permafrost could easily be a non-permafrost location within a hundred years.
And yet, the greenhouse theory is not above dispute. Kenneth Watt, a professor at the University of California at Davis, criticizes the theory, pointing out that all but 270 of the 11,600 weather stations in the US are in cities or at airports. James Goodrich, formerly chief climatologist for the State of California, states that 90 percent of the temperature measurement data supporting the theory came from "urban heat environments". According to Reid Bryson, professor of meteorology at the University of Wisconsin, the worldwide climate has gotten colder, not warmer over the last 40 years. He gives evidence for previous increases in world carbon dioxide not being a cause of global warming.
Permafrost, by definition, is permanently frozen ground. In the Western Hemisphere Arctic, permafrost depth extends 250 to 450 meters, whereas in Siberia it can extend to 600 meters. But Arctic summer temperatures are 0 degrees Celcius on average during the warmest month (colder towards the Arctic circle than at the pole). Ground called permafrost can be melted up to a depth of one meter in the summer. It is regions that are permanently covered with ice and snow that have totally frozen ground. But it is difficult to perform burial in such regions and difficult also to ensure the gravesite will not be lost. Antarctic temperatures average 11 degrees Celcius lower than Arctic temperatures and Antarctica is the least prone to earthquakes of all the continents. But distance, absence of national territorial boundaries claims, high winds and the depth of the ice make Antarctic burial conditions even more difficult.
A cryonics society can still perform valuable services for a PCI. Perfusion with cryoprotectants is the most obvious, but until the Ontario law requiring embalming of bodies shipped out of the province is altered, I cannot arrange this. If death is anticipated, a move to Quebec could get around this problem. A cryonics society could also monitor a gravesite, arranging for reburial if local warming occurred. Although this gets back to the problems of trusts, maintenance costs and survival of the society, it can't hurt. Safety can always be improved, even though there is no such thing as perfect safety.
My Will stipulates that I wish my remains to be preserved no matter how damaged or fragmented they may be. If I was in an airplane disaster and all that could be found of my remains was a finger that had been "rotting" for a month, I would still want that finger preserved as best as possible. This is in keeping with the fact that I do not place limits on the capacity of future technology to reconstruct and reanimate. (And the more remains there are to work with, the better.) It is also in keeping with my personal motto of "Never say die"!
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The word "permafrost" is an abbreviation for "permanently frozen ground". As geologists use the term, it is defined exclusively in terms of temperature -- moisture content may or may not be present. Permafrost is soil, bedrock, or other material that has remained below 0 °C (32 °F) continually for two years to tens of thousands of years.
In an idealized setting, permafrost would be expected wherever mean average air temperature is below 0ºC. On a yearly basis, the diffusion of the below-freezing temperatures into the ground exceeds the diffusion of above-freezing temperatures. As shown in Figure 1,
GRAPH OF PERMAFROST TEMPERATURE AT DEPTH (Figure 1)
close to the surface, there is an active layer that is not frozen in summer months. Just below the active layer, the ground is below freezing temperature all year (permafrost), but there is still a large temperature difference between summer and winter. At greater depth, typically 15 to 30 meters (30 to 100 feet) below the surface, seasonal fluctuations in temperature become less than 0.1 F (the depth of zero annual amplitude). At this depth, temperature is generally 3ºC - 4ºC higher than mean annual air temperature. Below this depth, temperature rises uniformly (due to heat from the earth's core) until the freezing point is exceeded and the ground is no longer permafrost.
In reality, ground surface temperature tends to be 1ºC - 6ºC below mean annual air temperature, in northern latitudes. Insulation due to vegetation & snow cover, interactions between terrain & solar radiation (northern slopes get less radiation than southern slopes), latent heat of freezing of soil water, water drainage & seepage, and other such factors account for the difference.
The depth of freezing is a function of both air temperature and
the thermal diffusivity of the ground substance. Granite has nearly
twice the thermal diffusivity as dense saturated sand, which in turn
has twice the thermal diffusivity of soft saturated clay. In
Churchill, Manitoba, areas of sandy soil type have an active layer of
2.5 - 3.8 meters depth, whereas areas of clay soil type have an active
layer of depth 1.0 - 2.5 meters. Prudhoe Bay, Alaska has a permafrost
depth of 610 meters (2,100 feet) in contrast to 405 meters (1,330
feet) ten miles inland of Barrow, Alaska, where the mean annual air
temperature is about 6ºC lower -- because of the greater thermal
conductivity of the siliceous sediments at Prudhoe Bay.
MAP OF NORTH AMERICAN PERMAFROST (Figure 2)
Figure 2 shows the distribution of permafrost in the polar region of North America. The continuous permafrost region is defined as that area wherein subfreezing ground exists at some depth for all points in the region. As Figure 2 indicates, there is permafrost in the ocean floor in the coastal regions of the Beauford Sea (near Inuvik).
PERMAFROST TEMPERATURE WITH DEPTH AT INUVIK (Figure 3)
Although permafrost is, by
definition, permanently frozen
ground, the exact subfreezing
temperature and seasonal variability
of temperature will depend upon mean
annual temperature, thermal diffusivity
of the ground substance, and depth
beneath the ground. Figure 3 and
Figure 4 show the contrasting
conditions at Inuvik, Northwest
Territories (NWT) and Resolute Bay,
NWT, in Canada. In Inuvik,
temperatures average -3ºC from a
depth of about 1 meter downward to 15
meters (total permafrost depth is
over 90 meters or 300 feet).
Seasonal variation becomes minor at 6
or 7 meters. In Resolute Bay,
average temperature runs from about
-14ºC at 1 meter to about -12ºC at 30
meters. Seasonal variation becomes
minor at about 15 to 20 meters.
In the Spring of 1988 the Cryonics Society of Canada assisted in the PCI burial of the father of a New Jersey businessman. The Funeral Director in Inuvik, David Hansen, proved to be willing and co-operative. This burial cost less than $4,000. At that time, the New Jersey man had also been in contact with the RCMP in Resolute Bay (who were in charge of burials in that small, remote town) and was quoted a burial price of $10,000 (insofar as burial machinery had to be flown-in). These expenses do not include the cost of flying the body into those northerly locations.
Some time after the first PCI, an inquiry came from California from another party seriously interested in PCI. In this case, Hansen had to decline the request because Inuvik residents were objecting to the use of their cemetery by Americans. Hansen was interested in the business opportunity offered by PCI and began pursuing the idea of a specifically designated gravesite for PCI, outside of Inuvik proper. His quoted estimate for this service was to be in the $30,000 to $35,000 range. Nonetheless, he has been running into problems with the local Indians over land claims for the property he seeks.
ILLUSTRATION/FIGURE/PICTURE OMITTED (Figure 4)
In Inuvik, at a burial depth of 3 meters (10 feet), temperatures average -3ºC, with July temperatures as high as -2ºC (Figure 3). At Resolute Bay, at 3 meters, temperatures average -14ºC, with July temperatures up to -7ºC (Figure 4). The active layer at Resolute Bay is half-a-meter. A depth of 15 meters (50 feet) would provide -13ºC with minimal seasonal variation, but burying a body at that depth would require special effort and expense.
There are doubtless other locations in Alaska and northern Canada which would be suitable for PCI other than these two sites described. Anyone seriously interested is invited to invest in long-distance phone calls to cities in the northern latitudes. Figure 5 shows mean annual temperature isotherms (ºC) for Canada, illustrating regions of discontinuous and continuous permafrost. Mean annual ground temperatures tend to be about 4ºC lower than mean annual air temperatures.
NORTH AMERICAN PERMAFROST ZONES (Figure 5)
A human body freezes below a temperature of 0ºC because of its salt composition, which depresses freezing point. Freezing does not occur uniformly, but results in ice crystals and supersaline pockets -- freezing point may be greatly depressed in the pockets. One argument against PCI cited the reactivity predicted by the Arrhenius equation -- ignoring the drop in molecular mobility with freezing.
The lower cost of PCI and the vulnerability of cryonics organizations to legal or financial failure can also make PCI attractive. When conventional burial is the only alternative, PCI offers reasonable hope. PCI is less vulnerable to earthquakes, power failures, civil strife, hyperinflation, war and other catastrophes.
PCI could make one vulnerable to the greenhouse effect of global warming, however. Since 1860 atmospheric carbon dioxide has increased 25 percent. Some authorities have estimated average global temperature increase to be 0.5 to 0.7ºC over that time period, with the greatest increase in the last decade. The warmest years on record since 1900 are 1988, 1987, 1983, 1981 and 1986, in that order. Greenhouse gases (carbon dioxide, methane and chlorofluorocarbons) could warm the earth several degrees Celcius in the next 50 to 100 years. Winter temperatures toward the poles would increase twice as much as the global average, but the increase would not be so great for summer temperatures, which is the most serious concern in PCI.
Other experts have disputed these claims for a greenhouse effect. Extremely accurate measurements of earth temperatures by satellites have shown no global warming in the past 10 years. Although human activities add 5 to 15 billion tons on carbon dioxide yearly to the atmosphere, the 1980 Mount St. Helen's volcano added 190 billion tons of carbon dioxide in what is considered a medium size eruption. There are an average of 100 volcanic eruptions on earth every year.
Of course, preservation at liquid nitrogen temperatures is best. Nonetheless, circumstances often make liquid nitrogen preservation difficult, and in such cases PCI is much to be preferred over warm climate burial. In the case of the New Jersey businessman, lack of pre-mortem suspension arrangements and a family opposed to liquid nitrogen suspension made PCI the only acceptable alternative. He hopes to eventually have his father frozen in liquid nitrogen when family problems are resolved.
Cryonics organizations stress that they are also of value in that they provide ongoing support combined with the motivation and financial means for reanimation when technology makes reanimation feasible. Yet few people seriously believe that reanimation will be feasible in less than 50 or 100 years. Can anyone reasonably estimate costs for 50 or 100 years in the future? Lifepact and the Reanimation Foundation offer means of arranging for reanimation outside of those provided by cryonics organizations offering liquid nitrogen suspension services.
In the struggle for survival, PCI should not be ignored.
Cryonicists should rationally explore and risk every possible
solution. PCI may be of value as a short-term solution in some cases
-- and a long-term solution in others (especially where liquid
nitrogen suspension is not an option).
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Permafrost Cryonic Interment (PCI) has not been subject to
controlled experimental study. Some cryonicists believe that
preservation at temperatures above liquid nitrogen is of no value.
This has not been proven. The study of the historical preservation of
mammalian remains gives some indication of what preservation is
possible, and by what means. Mummification, accidental Arctic
freezing and peat bog preservation all provide useful information.
The best-preserved tissue from Egyptian human mummies has been the skin. The explanation for this is that mummification involved dehydration by embedding the eviscerated body in crystalline salts (natron) -- putting the skin in direct contact with the dehydrating agent. DNA extracted from the skin tissue of mummies is as much as 5% the amount expected from fresh tissue. Although most of the DNA fragments are less than 500 base-pairs long, some are over 5,000. (1)
The oldest-known example of preserved human cell structure and
DNA comes from specimens about 8,000 years old found in a swampy
peat-bog of central Florida. Such preservation is all the more
amazing because it occurred in an aqueous, albeit anaerobic,
environment. DNA of 8 to 20 kilobase-pairs were found. Brains were
so well-preserved that it was possible to identify such structures as
the corpus callosum, putamen and thalamus. It was even possible to
distinguish white matter from gray matter, and identify vertical
axonal fibers in the latter. (2)
The legend of whole mammoths being perfectly and permanently frozen is no more than a myth. A 1961 review (3) observed that nearly all frozen mammoths remains have been found in Northeastern Siberia. Of 39 discoveries of these remains, only 4 were nearly complete cadavers. All the frozen specimens were rotten and usually somewhat mutilated by predators. It is conceivable that some mammoths could have been quickly preserved by a snow avalanche. But the specimens found in practice have been victims of mudflow or river-bank cave-ins -- who were frozen somewhat slowly.
A more recent study (4) of a frozen mammoth calf found in 1977,
dated 40,000 years old, extracted 2 to 5 micrograms of DNA per gram of
frozen tissue. This is just under 1% of what could be expected from
Some cryonicists claim that the Franklin Expedition is proof of the unworkability of PCI. For the University of Alberta scientists who investigated this Expedition (5), it is a moral lesson in the hubris of technophilia comparable to the space shuttle explosion.
On 19 May 1845, 133 officers and men under Sir John Franklin sailed down the Thames to find a Northwest Passage to the Orient which would enhance the glory and power of the British Empire. Although they had provisions enough to last them several years, every last man perished. The expedition's two ships became locked in the northern Canadian ice early in the Fall of 1845.
Three men died during that first winter: John Torrington (1JAN46), John Hartnell (4JAN46), and William Braine (3APR46). All three men evidently died of tuberculosis and pneumonia. But the lead levels found in their hair exceeded normals for the period by 20 to 50 times. The new technology of canning food -- which was expected to keep the Franklin Expedition alive for years -- may have sabotaged the mission. Food was evidently contaminated with lead solder -- and in many cases the solder did not completely seal the cans. Lead poisoning and putrefied food probably contributed to the mysterious disappearance of the rest of the expedition.
The three men who died in early 1846 were given "decent Christian burials", on Beechey Island -- a tiny islet on the southwestern tip of Devon Island, 100 kilometers due east of what is now the town of Resolute Bay. Torrington was buried at a depth of 1.5 metres, Hartnell 0.85 metres and Braine 2 metres. It would not have been an easy task for members of the Franklin Expedition to dig these graves in winter, although this is evidently what was done. The University of Alberta scientists began digging-up the graves on 12AUG84 and at a depth of 10 centimetres encountered "cement-like permafrost". It took two days of hard digging to reach Torrington's coffin. The work was so difficult that the other two sailors could not be exhumed until the Summer of 1986.
Although the skin seemed well-preserved in the 3 men, most of the internal tissue showed destruction of virtually all cellular structures. Torrington was the best-preserved, so the results of his autopsy should be taken the most seriously. (6) Braine had been allowed to putrefy quite a bit before burial and lesions in skin as well as muscle seem to be the teeth marks of rats. Hartnell had been autopsied before burial and had been subsequently exhumed temporarily in 1852 by a search party seeking to explain the mysterious disappearance of the Franklin Expedition.
Do the results of Torrington's autopsy disprove the possible efficacy of PCI? Probably not. Studies of normal cadavers have demonstrated that shortly after cell death pH drops and intracellular enzymes begin self-digestion of tissue by a process known as autolysis. The membranes of cellular organelles called lysosomes are ruptured, releasing hydrolytic enzymes which accelerate the autolytic process. (7) Putrefaction by the anaerobic organism Clostridia is normally initiated by autolysis such that putrefaction and autolysis proceed concurrently.
The skin seems much more resistant to autolysis and putrefaction than other organs, probably due to more rapid cooling after death and the compact structure of the epidermis. Sadly, the central nervous system seems particularly vulnerable to rapid hyperacidity and autolysis. In one study, after 2 hours of autolysis "the cell membranes were destroyed and the synaptic formations could no longer be distinguished." (8) Another study of post-mortem neuron degeneration showed that almost all neurons had lost their nuclei within 48 hours of death. (9) Chromosomes seem to be particularly vulnerable to autolytic hydrolysis.
Torrington's body was probably kept below the decks of the ship for at least several days while the carpenters built his coffin and others performed the difficult task of digging his grave. Air temperatures below deck were probably at least 10 ºC (the high-tech ships had "a tubular boiler and steam-forming apparatus which conveyed hot water in a 30-centimeter diameter pipe under the deck to warm the men's berths, and all parts of the vessels" (5)). In fact, the University of Alberta physician who autopsied Torrington, Dr. Roger Amy, concluded: "The marked autolysis of the brain suggests that Torrington had been kept warm for a while after death, possibly while being prepared for burial while the grave was dug." (6)
What may be more relevant to the feasibility of PCI is the fact
that bacteria cultured from Braine's bowel were successfully
"reanimated" at the University of Alberta.
Since preservation of identity is the objective of would-be immortalists, preservation of DNA is of little value except in cases where the clone of a loved-one is preferred over a complete loss. Nonetheless, the fact that DNA can be recovered after 40,000 years or longer under conditions uncontrolled by human intention and far from ideal, provides hope that controlled preparation at temperatures nearer 0ºC has potential for identity-preservation.
Just as liquid nitrogen suspension makes use of such techniques as cooling soon after death, infusion with anti-ischemic agents, blood washout and perfusion with cryoprotectants -- so too would an ideal PCI make use of these procedures. Other adjuncts could include vacuum-packing, dehydration or glutaraldehyde fixation. Moreover, even if such high temperature preservation does fail to maintain identity, it is by no means certain that even fragmentary human remains could not be used for identity-reconstruction in a far-future of technological revolutions more far-reaching than nanotechnology.
During the course of our lifetime we manifest our identity in
manifold ways almost every minute of our waking life. These
manifestations leave permanent traces on the structure and direction
of existence which a future superscience may someday be able to
decipher. The addition of biological remains to this
identity-reconstruction problem can only be of benefit.
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The low temperature of Permafrost Cryonic Interment (PCI) is bound to enhance preservation by any chemical preservation technique. As discussed in a previous article (1), some remarkable examples of mammalian preservation have been achieved by natural freezing (2) and natural chemical (3) means. The possibility of using both these methods along with modern technology is well worth investigating if it can mean minimized storage cost, effort and reduced vulnerability to storage-failure.
In the case of peat-bog preservation, although many brain structures and fibres were preserved in remarkable detail (3), neurons were lost. The anerobic, acidic medium of the peat-bog sterilized the brains against bacterial decomposition. The lipid (fat) content of the brains prevented dissolution into the aqueous medium, since oil and water don't mix. But perfusion of the peat-bog acid into the brains would have been slow in natural conditions.
One argument that PCI would be insufficient to preserve human identity for hundreds of years is based on reference to the rates of chemical reaction in the -20ºC to 0ºC temperature range as predicted by the Arrhenius equation. But if ice formation immobilizes molecules below freezing, the Arrhenius equation is irrelevant as a predictor. Nonetheless, as freezing progresses, pockets of very concentrated salt solution form in which the freezing point is depressed to -20ºC or lower. Such pockets could be highly reactive in terms of breaking down and dissolving biological structures such as synapses. Unlike freezing damage, dissolution of structure likely represents a loss which cannot be repaired.
Freeze-drying units (commonly used by museums), which freeze the
flesh and then vaporize the ice, might be an answer to this problem,
although this technique works best with small pieces of tissue. A
blood washout with ethyl alcohol would have a very dehydrating effect,
but there is danger of dissolving-away lipid material in the brain.
Alcohol can also precipitate proteins or render them more readily
coagulated by salts.
Another alternative would be to perfuse (after blood washout) the pre-PCI body with a cocktail which included not simply cryoprotectants, but substances which would cause the formation of gels. Gel formation could simulate vitrification for sub-zero temperatures above the freezing point of salt water -- preventing dissolution of structure.
A gel is a dispersion of solid particles linked together to form a structure with some mechanical strength. It can be viscous, like a gum, or elastic, like rubber. Gums are added to ice cream to retard ice crystal growth, an advantage in minimizing freezing damage. Gels, or colloids, can be hydrophobic or hydrophilic. Since the former are more readily precipitated by salt, hydrophilic colloids (like proteins) are preferred.
Gels or colloids are generally the result of polymerization. Just as vulcanization strengthens rubber by adding cross-linking bonds of sulfur, globular proteins (albumins, globulins, histones, etc.) can be made to unfold and cross-link with fibrous proteins (collagen, fibrin, keratin, etc.) to form a strong colloidal network. Table jellies are generally made from gelatin, a protein, but carbohydrate polysaccharides such as pectin and agar also polymerize to form gels.
Another exogenous perfusate which could conceivably be used is
sodium silicate (water glass) which reacts with acid to form
monosilicic acid and polymerizes to rigid three-dimensional silica gel
(used as a drying agent in air-conditioning equipment).
A study of embalming practices has the potential of yielding information of value for chemical preservation of the body. The most authoritative text on this subject, THE PRINCIPLES AND PRACTICE OF EMBALMING by C.G. Strub and L.G. Frederick, contains no references to scientific literature.
At the foundation of embalming is formalin, an aqueous solution saturated with formaldehyde gas, which constitutes 40% by volume and 37% by weight of the solution. Formaldehyde coagulates protoplasmic protein, turning it from a soft soluble form to a hard insoluble form which is resistant to both autolytic and bacterial proteolytic enzymes. Moreover, formaldehyde kills bacteria by coagulating bacterial protoplasm and has a drying effect upon tissue because of its strong affinity for water. Phenol, which is soluble in water, alcohol and glycerine, is a very powerful disinfectant. (It may be worth noting that the hard-rubber-like resin Bakelite is a polymer of formaldehyde and phenol -- although heat is generally required for its formation.) Methanol may also be used as an adjunct insofar as it is both a disinfectant and a stabilizer-of-formaldehyde (by preventing formaldehyde from changing to powder). Wetting agents, such as sodium lauryl sulfate, reduce surface tension in capillaries, allowing better formaldehyde perfusion.
Embalmers also use ingredients such as colorants and humectants, to allow the skin to appear moist and natural, but this is of little interest to chemopreservation. Embalmers in North America rarely compound their own fluids -- relying instead upon pre-mixed formulations supplied to them by manufacturers.
Frederick and Strub point out that even such a thoroughly
embalmed tissue as shoe leather will eventually disintegrate when
subject to an atmosphere of airborne moisture, bacteria and mold.
This speaks of the necessity of a protective seal surrounding even the
best chemically-preserved body. A stunning example of what a
protective seal can do is revealed by the autopsy of
St. Bees Man,
an English nobleman who had been buried over 700 years ago (described
in the book THE BOG MAN by Don Brothwell). Very shortly after death
(if not before), St. Bees man had been wrapped in thick shrouds over
which a wax and honey preparation had been poured, and then wrapped
with a sheet of lead, packed with clay and placed in a wooden coffin.
Seven hundred years later, the skin had a "fresh pink appearance".
Eyes, heart, intestines, liver and other tissue appeared intact and
"the blood vessels even appeared to contain 'fresh' blood." (Autopsy
findings of St. Bee's Man, including histological and electron
microscope examination, were presented by E. Tapp and D.M. O'Sullivan
at the Fourth European Members Meeting of the Paleopathology
Association, Middleburg-Antwerpen, 16-19 September 1982.)
Like embalmers, microscopists seek to preserve tissue from autolysis and bacterial decomposition. Microscopists are concerned with coagulating cell contents into insoluble substances, avoiding distortion or chemical deposits (artifacts) and rendering cell structures visible or amenable to selective staining. A good reference is THEORY AND PRACTICE OF HISTOLOGICAL TECHNIQUES by John Bancroft and Alan Stevens. As with embalming, reactions which stabilize proteins are the most important. As with embalming, formalin is the most general-purpose fixative, although microscopists have given much more attention to the use of special-purpose fixatives for specific tissues. The formalin will contain 10%-14% methanol as a stabilizer and buffer salts to counteract the acidity of the solution.
Mercuric chloride is a powerful protein precipitant which penetrates and hardens tissue fairly quickly. It forms intermolecular mercury links between SH, carboxyl and amino groups. Not only does it cross-link protein, but it also cross-links lipid and carbohydrate substances (particularly the mucins and unsaturated lipids). However, it forms deposits of uncertain chemical composition and depresses the freezing point. Despite the excellent fixative properties of mercuric chloride, it is being used less and less because of concern over pollution from waste fixative solutions.
A good fixative for preserving chromosomes is a mixture of formalin, acetic acid and 1% chromic acid. Because chromic acid is a powerful oxidizing agent, it is only added to the mixture immediately before use. Ethanol and methanol are also common fixatives for nucleic acids. DNA which has been collapsed by these alcohols reverts substantially to its original form upon rehydration. Carnoy's fixative (ethanol 60ml, chloroform 30ml and glacial acetic acid 10ml) is another recommended mixture. Aldehydes like formalin are not good fixatives for nucleic acids.
Since the essential objective of cryonicists is to preserve identity, special attention should be given to fixatives for the brain. The brain is composed of little connective tissue, but is high in lipid and water content. Alcohols and other substances which dissolve lipid (particularly myelin, which is high in cholesterol, cerebroxide and phospholipid) should be viewed with suspicion. Substances which fix lipids should be of particular interest. A solution of 10% formalin and 10% calcium chloride has been recommended for lipid fixation. Also used for lipid fixation, particularly in frozen tissue sections, is Elftman's fluid (5gm mercuric chloride and 2.5gm potassium dichromate in 100ml of water).
Embedding the brain in paraffin is a common technique. Since paraffin and water do not mix, the brain is first dehydrated with ethanol or methanol (which also do not mix readily with paraffin). Then the ethanol or methanol is washed-out with a clearing agent such as xylene, which does mix readily with paraffin. The brain is then perfused with warm, soft paraffin at above room temperature -- which will solidify at room temperature. The brain could then be encased in plastic for even better preservation. But the loss of lipid by alcohol washout and further damage to fine structure by high temperature treatment are of serious concern. For PCI, mineral oil could be substituted for paraffin, since it would be paraffin-like at PCI temperatures. Washout with a clearing solution could be avoided by using dioxane or butanol (which mix readily with paraffin) rather than ethanol or methanol for dehydration. The amount of loss of lipid and fine structure by this technique would need to be investigated.
Because formaldehyde preserves lipids as well as proteins, it would seem to be especially of value for the brain. A study (4) of human brains preserved in formaldehyde for up to 24 years showed that the preservation of lipids was not uniform: cholesterol, cerebrosides, sulphatides, phosphoinositides and sphingomyelin remained unaffected, whereas lecithin, phosphatidylethanolamine and phosphadidylserine were broken down. Since unbuffered formaldehyde solutions are acidic, at least part of these breakdowns are attributed to slow hydrolysis. Formaldehyde for the brain should be in special formulations which do not contain methanol, since this alcohol dissolves brain lipid.
Tannic acid has been used since Roman times to tan leather. Only
in this century has glutaraldehyde been combined with tannic acid to
cure hides into leather. Glutaraldehyde, like formaldehyde, seems to
cross-link protein by attaching to the epsilon-amino groups of lysine,
hydroxylysine and, to a lesser extent, the imidazole ring of
histidine (5). Three or four glutaraldehydes will polymerize and
connect epsilon-amino groups of protein amino acids in a
cross-linkage. Although the induction of crosslinking is slower in
acidic or dilute conditions for both formaldehyde and glutaraldehyde,
once the cross-links are formed, those of formaldehyde are easily
hydrolyzed, whereas those of glutaraldehyde are essentially
irreversible. An improved fixation has been seen with mixtures of
formaldehyde and glutaraldehyde. This may be due either to more rapid
perfusion of the formaldehyde (6), to formaldehyde reduction of
glutaraldehyde-induced hypoxia (7), or both. Glutaraldehyde is
sometimes preferred simply because formalin fumes are so much more
offensive (6). As a fixative for lipids, however, glutaraldehyde has
little demonstrative value (8). Despite the fine preservation
produced by glutaraldehyde, its slow rate of perfusion makes its value
problematic for large tissue samples (like whole brains). For this
reason, it has also been used in combination with acrolein, an
aldehyde with twice the perfusion speed of glutaraldehyde (9). The
terrible odor and destruction of enzymes by acrolein make it unpopular
with histochemists, but these concerns might not be as important for
cryonicists. Use of glutaraldehyde with osmium tetroxide and mercuric
chloride has also been common (10).
It is commonly believed by cryonicists that the locations of
synapses in the brain is the key to memory and identity. I find it
convincing that not only the location of synapses, but the bulbousness
of those synapses (frequently used synapses become more bulbous and
facilitative of transmission) is of importance (supportive of a neural
net model of consciousness). Chemical composition of the synapses may
also be of importance. Much is unknown. Many proponents of liquid
nitrogen suspension maintain that only such extreme freezing can
guarantee that all the essential structural components are maintained.
Irreplaceable loss of structure means randomized rearrangement beyond
recovery. Molecular structures can be said to be irreplaceably
randomized when the molecules go into solution. As Fred Chamberlain
has pointed-out, freezing a brain to liquid nitrogen temperatures
could be analogous to hitting a circuit board with a sledgehammer.
The freeze-fracturing could be so extensive and randomizing that
deducing original synaptic connections is hopeless. By contrast, low
temperature chemopreservation may maintain enough structure for better
repair by nanotechnology.
Searching for literature concerning preservation by natural means, or by means devised for keeping food, leather-making, embalming or microscopy, is a helpful start in answering questions. But the questions of concern to cryonicists may be unique and require special-purpose research. If fixative preservation of synaptic structure is good enough for electron microscopists, it should be good enough for cryonicists. But can such techniques be applied effectively for a whole brain? And for how many years are the tissues fixed?
One of the motivations for a chemopreservation PCI is the idea of cutting the costs of cryonic maintenance. But if it is proven that identity can only be maintained with PCI by expensive chemical perfusion techniques from a bed-side suspension team, the cost-advantage of PCI would be lost. PCI may then only interest dedicated cryonicists who have no trust in the ability of cryonics organizations to maintain patients in the face of financial, legal or social disaster.
Or, it may be that low-cost chemopreservation PCI methods may represent an indeterminate threat to the loss of identity which frugal cryonicists are willing to risk. Since there are many degrees of loss of brain structure, there may be degrees of possible identity-loss, which some cryonicists may want to evaluate by cost-benefit analysis in light of their own values.
There are many questions to be answered, of both a cost-benefit
and scientific nature. Unfortunately, life (and death) often calls
for immediate action before all the questions can be answered.
(return to contents)
The claim that Permafrost Cryonic Interment (PCI) may be a means
by which human biological identity can be preserved for 100 years is
certainly open to challenge. And the strongest challenge to this
claim probably comes from the evidence of the science of cryobiology.
But one must look to the science of cryobiology to rationally assess
the evidence, not to cryobiologists themselves, most of whom seem
unable to comprehend the difference between what current science can
do and what future science (nanotechnology) will be able to do. The
cryobiologist Arthur Rowe has often been quoted for his statement that
"Believing cryonics could reanimate somebody who has been frozen is
like believing you can turn hamburger back into a cow." And paragraph
2.04 of the Bylaws of the Society for Cryobiology specifically
excludes cryonicists from participation in the Society.
The study of the effects of low temperature on biological phenomena has been going on for many years. In the 1930s and 1940s, studies of the preservation of frozen food played a major role in motivating research. The science of cryobiology was given a great boost in 1949 when it was discovered that glycerol could be used to protect bull spermatazoa against freezing injury. The next year it was discovered that the same technique could be used to protect human red blood cells. The founding of these two large industries of practical importance was a great impetus to research. Later in the 1950s, Dr. Audrey Smith froze hamsters and was able to revive specimens whose body water was more than 50% ice. In 1959 it was discovered that dimethyl sulfoxide (DMSO), which passes through cell membranes more readily than glycerol, is also useful as a cryoprotectant. When Robert Ettinger wrote THE PROSPECT OF IMMORTALITY in the early 1960s, he anticipated that the freezing of organs for transplant, and true suspended animation for whole animals, would not be long in coming. Unfortunately, this was not the case. Significantly, perhaps, the single most comprehensive textbook on cryobiology is still CRYOBIOLOGY, edited by Harold Meryman in 1966.
Until recently, a large part of the research has been purely
empirical: experimenting with the cryoprotectant qualities of
difference substances and mixtures of substances, experimenting with
freezing and thawing various organisms at various rates of temperature
change, etc. Although there have been some breakthroughs (most
notably the freezing of 8-cell mouse embryos to liquid nitrogen
temperature and rewarming them to obtain live mice in 1972 -- and
using the same process with a human 8-cell embryo in 1982 to establish
a human pregnancy), subsequent developments have been far slower than
might have been predicted from the discoveries of the 1950s. But
theoretical questions have been addressed, most notably, an inquiry
into the mechanism by which freezing damage occurs, and the mechanism
by which cryoprotectants protect.
Cells and tissues that are rapidly frozen are less likely to be viable upon rewarming than are cells and tissues frozen slowly. In slow freezing, ice begins to form outside rather than inside of cells. There are several reasons for this: (1) Since metabolism is an intracellular process, and since cold is applied from outside-to-inside, it tends to be colder on the outside of cells (2) Solute concentration tends to be lower in extracellular fluid (3) Extracellular ice crystals can grow and spread more easily than intracellular ice (4) Extracellular ice increases solute concentration of the unfrozen portion, which osmotically draws water from cells. Slow freezing gives time for water to be osmotically drawn from cells into the extracellular space. Intracellular ice is correlated with cell damage, whereas extracellular ice tends to be much less damaging. There is evidence, however, that it is the method of thawing intracellular ice, rather than the intracellular ice itself, which is damaging (1). Slow warming of intracellular ice seems to be more damaging than rapid warming, possibly due to recrystallization (2).
An early assumption about freezing damage is that ice-crystals form which puncture membranes and damage cellular structures. However, when an ice crystal is formed, even if its shape is spear-like, the crystal does not grow through a membrane or organelle (although mechanical pressure on the membrane could probably force it into the spear). A major breakthrough in the theory of freezing damage occurred when Lovelock (3,4) showed that the hemolysis of red blood cells could be correlated with increased salt concentration in a freezing solution. (In freezing of salt solutions, ice tends to crystallize as pure water-ice, leaving a more concentrated salt solution in the unfrozen portion. With more freezing-out of ice, the salt solution becomes more concentrated until -- at some high concentration and low temperature (the eutectic concentration and the eutectic temperature) -- the eutectic solution freezes.)
Lovelock believed that high levels of electrolytes produced by freeze concentrations result in salt denaturation in proteins, enzymes and, especially, cell wall membranes. Meryman, however, demonstrated that increasing concentrations of sucrose (which does not cross the cell membrane), has the same hemolytic effect on red blood cells (5). This suggests that it is the osmotic effect of reduced cell volume and cell shrinkage (with loss of water) that causes the damage, rather than electrolyte-induced denaturation. Part of the mechanical damage due to cell shrinkage may be the result of cell dehydration and the cross-linking between cellular enzymes, membranes and other constituents brought into close contact by the loss of water.
Mazur has challenged this cell shrinkage theory of freezing damage by presenting evidence that freezing damage increases with a decrease in the unfrozen water fraction, even when the composition of the residual unfrozen water remains unchanged (6). Mazur suggests that the expanding ice field puts physical pressure on the shrinking cells, causing deformation which could be damaging -- especially at low temperatures (due to greater structural rigidity?). Others contest Mazur's conclusions on the basis of his experimental methods&assumptions (7) or on the correlations of freezing injury with unfrozen water fraction in the presence of glycerol (8).
It has also been suggested that lysosomes (intracellular
organelles containing hydrolytic enzymes) are ruptured in freezing,
and are therefore a major factor in freezing damage. Nonetheless,
increased hydrogen bonding (or even salt denaturation) at low
temperatures may significantly impair the activity of these
enzymes (9). Also, hydrolytic enzymes of lysosomes are most active in
an acidic environment, such as is found within lysosomes. This is
another reason to keep pH high: to prevent hydrolysis.
To a cryobiologist, freezing injury is judged in terms of the ability of a cell, tissue or organism to function normally upon thawing. If normal function is no longer possible, the cryobiologist says the damage is irreparable. The cryonicist or nanotechnologist takes another view: damage to a biological structure may someday be repaired, provided the tissue is preserved in some form. The cryobiologist may despair at the damage due to enzyme denaturation from high salt concentrations at low temperature. But the cryonicists take heart, knowing that high salt concentrations have preserved the skins of Egyptian mummies for thousands of years in a hot climate. Denaturation and cross-linking of enzymes is precisely the objective sought in chemical fixation by formaldehyde or glutaraldehyde. Therefore, "freezing damage" may be a means of chemical preservation, maintaining structure until nanotechnology can un-crosslink and otherwise repair.
Cryonicists do, however, fear degradation or loss of structure. Such losses occur primarily through hydrolysis or dissolution. Once a structure has gone into solution, it is probably lost. Dissolution is promoted by acid, by liquid and by high temperature. Free-radical damage might also contribute to randomizing degradation, but it could (ironically) contribute to preservation by promoting cross-linking.
Cryonicists seeking liquid nitrogen preservation think like cryobiologists insofar as they seek to use cryoprotectants. Cryoprotectants lower the temperature at which fluids freeze. Cryoprotectants promote vitrification (glassification) rather than crystallization when freezing does occur -- thus reducing freezing injury (possibly also diluting electrolytes which, if concentrated, can cause denaturation (6)). But cryoprotectants are toxic themselves (8). The permafrost cryonicist probably has little to gain from cryoprotectants. The higher the temperature at which freezing occurs, the less the likelihood of dissolution, hydrolysis and free-radical activity.
ICE FORMATION WITH LOWERING TEMPERATURE (Figure 1)
Cells are mixtures of solutes
of varying molecular weights and
eutectic substances. NaCl has a
eutectic temperature of -21.6ºC,
whereas CaCl2 (also a naturally
occurring biological electrolyte)
has a eutectic temperature of
-55ºC. A mixture of NaCl and
CaCl2 in water will show these
two eutectic temperatures upon
freezing, but animal sera do
not, evidently because of
binding of the salts to
proteins and other cytoplasmic
materials (10). As seen in
Figure 1 (11), about 90% of
muscle water is frozen at -15ºC.
But this figure is misleading.
Much of the cell water forms
hydrate complexes with enzymes
and other proteins -- water which will not "freeze" because it is
already in a bound state. Thus, the amount of "free" water at -15ºC
will really be less than 10%. Moreover, other cells show even higher
rates of freezing, for example yeast cells are 90% frozen at -9ºC and
human red blood cells are 90% frozen at -7ºC (6). Measures of
electrical resistance to electrolyte flow become very high very
suddenly at -34ºC, for animal serum (10).
One might wonder, how cold is cold enough for permafrost preservation? Even granted that some biochemical reactions can occur down to -140ºC, there is strong evidence that algae, bacteria and even crustaceans have been reanimated after being frozen at least a thousand years in the Siberian permafrost (12). Streptococcus pyrogenes bacteria have been freeze-dried and maintained for 20 years before reanimation without loss of viability, virulence, or immunological and biochemical characteristics of bacteria (13). In another study of 100 strains of bacteria freeze-dried and stored for 10 years at room temperature in the dark, gram-positive bacteria tended to be easier to re-animate than gram-negative bacteria (14). Most bacteria seem capable of withstanding freeze-drying by almost any method (15). Yeast is routinely freeze-dried and reanimated for the leavening of bread. Protozoa, however, have not been successfully freeze-dried and reanimated (16).
Studies on the freezing of meat products offer insights into the adequacy of PCI alone to preserve human biological structure (17,18). Meat stored below 15ºF (-9ºC) will not be vulnerable to microbial growth (all bacteria, yeasts and molds are dormant). Meat quality tends to be judged by flavor, aroma, juiciness, color and tenderness. On the basis of these criteria, beef has a shelf life of 4 months at -12ºC and 6 months at -18ºC. The increased toughness of the meat is probably due to increased cross-linking of protein, which may not be a serious concern. The shorter shelf-life of pork is indicative of the fact that the higher fat content makes pork more vulnerable to rancidity. In fact, most of this damage due to oxidation occurs on the outer layers of the meat exposed to air. It is estimated that improved packaging improves shelf life as much as an 11ºC drop in temperature. Also, the addition of nitrites can reduce the oxidizing effects of iron. Cat brains stored at -20ºC for 203 days show spontaneous ECG activity (19). Nonetheless, hydrolysis of protein and amino acids is measureable at -20ºC over 6 months in frozen poultry. It is unlikely that permafrost temperature alone would be adequate to preserve structure for cryonic purposes for 100 or more years.
(For more details on the process of vitrification, see my essay
in Cryonics and for more information on eutectic mixtures see
for Cryonics from Metallurgy and Ceramics.)
Keeping in mind that loss of structure is due to hydrolysis, microbial decomposition, oxidation and dissolution, the low temperature of PCI can only assist other efforts to preserve structure. Sealing in wax and/or lead as described for St. Bee's Man (20) should provide considerable protection from oxygen. A water-saturated Magnolia leaf was found to maintain its structure for nearly 20 million years, thanks to low oxygen and low temperatures (21). The fact that the presence of water did not lead to loss of structure over such a long period is encouraging. The effects of other free radical processes in cryopreservation are still indeterminate (22), but probably deserving consideration. Free-radical processes, hydrolysis and dissolution could be virtually eliminated with the removal of water, although there would be greater cross-linking and denaturation of proteins. (These cross-linking processes are the basis of chemical preservation, but one could reasonably ask: how much cross-linking can occur without a loss of recoverable structure?)
In freeze-drying, the subject could be brought to a very low temperature and then the ice could be evaporated (in a vacuum or very dry atmosphere) over a very long period of time. (The lower the temperature of freeze-drying, the less damaging it is -- but the process takes longer.) The Smithsonian Institute has freeze-dried animals as large as a 6-foot alligator (23). Cryobiologist Greg Fahy, in conversation with me, declared that freeze-drying results in irreparable damage to membranes. He said that the removal of water from membranes results in a complete loss of the phospholipid bilayer structure. Later, however, he said that the phospholipid bilayer structure would probably not be lost in tissue that is chemically fixed before the freeze-drying process is begun.
At the foundation of chemical preservation is formaldehyde. Formaldehyde eliminates the problem of microbial decomposition, would assist salts in the denaturation of lysosome enzymes, promotes cross-linking and has a dehydrating effect. Although the addition of formaldehyde cannot by itself eliminate intracellular water, it probably binds with water in some way to render it less capable of hydrolysis and dissolution. Further research on the use of formaldehyde or other dehydrating agents would be valuable.
In conclusion, the demonstrable preservation benefits to be
derived from formaldehyde and other chemical preservatives, combined
with isolation from oxygen and the low-temperature of PCI may result
in preservation of enough of the structural basis of identity for
nanotechology to repair.
(return to contents)
Permafrost Cryonic Interment (PCI) cannot be implemented by
simply burying a person in some northerly location -- not if it has
any hope of working. Serious thought and preparation needs to be
given to proper chemical preparation, dehydration (perhaps), burial
container, burial locations and provisions for reanimation. Research
will be needed, and a decision will have to be made how to pay for
that research. Cost itself is a very serious matter, insofar as the
possibility of a low-cost cryonic alternative is a key motivation
behind the development of PCI. The more "bells and whistles" are
added to PCI, the better the chance that it will work -- but the
higher the cost. Ultimately, a menu of options may be the solution to
Since the low temperature of permafrost alone is clearly inadequate to preserve memory and identity for 150 years, and since relevant scientific data is hard to obtain on what chemicals would be the best adjunct for PCI, the issue of chemical preparation is probably the most difficult. Research and experimentation is badly needed -- and this raises serious problems in terms of cost and the possibility of inciting animal rights activists.
The best clues for a good chemical formulation probably come from research on chemical preparations for fixation of specimens for microscopy. Insofar as it is ultimately the fine structure of brain tissue that we want to preserve, examination of recent papers on fixation of neural tissue for electron microscopy is probably the starting point for a formula with the greatest specificity. The most common procedure appears to be perfusion of animals with a mixture of paraformaldehyde (2-4%) and glutaraldelyde (0.05-6%) in sodium phosphate buffer (pH 7.2-7.4) at 4ºC with osmium tetraoxide postfixation (1,2,3,4,5). A book by J.A. Kiernan (6) has a table of properties of commonly used fixatives and detailed evaluations of each fixative. A lucid history of techniques for perfusion fixation of neural tissues for electron microscopy has been written by Williams&Jew (7).
Efforts to preserve brain tissue must take cognizance of the fact that water constitutes 81.6% of the gray matter and 71.6% of the white matter. Lipid constitutes 32.7% of the dry weight of the gray matter and 54.9% of the dry weight of the white matter. Unlike adipose tissue, brain lipid is composed of no more than a few percent of triglycerides or free fatty acids. Gray matter lipid is almost entirely cholesterol and phospholipid, (cell membrane constituents), whereas the white matter is about half phospholipid and a quarter each of cholesterol and galactolipid (8). Preservation of white matter myelin lipid is probably less crucial for the preservation of memory and identity than is the preservation of cell membranes, particularly synaptic membranes. Coagulation of cell protein is also very important, particularly in the region of the synapses (to encase vesicles).
The value of formaldehyde in the coagulation of proteins is well known, but it has also been shown to preserve many brain lipids for at least 24 years (9). Unfortunately, the lipids which were not well-preserved were phospholipids -- cell membrane constituents. Nonetheless, this may have been due to the acidity of the formaldehyde, and a well-buffered basic solution could therefore help lipid preservation. Also, phospholipid solubility can be significantly decreased by adding calcium chloride (usually 1-2%, ie, 1-2gm/100ml) to the formaldehyde solution (6,10). Addition of 2% phenol to the formaldehyde may markedly accelerate its speed of action, as well as enhance sterility (11). The wetting agent sodium lauryl sulfate also improves formaldehyde perfusion. Because formaldehyde so readily forms solid formaldehyde hydrates (paraformaldehyde), 11 to 16% methanol is usually present in commercial formalin, for storage at low temperatures. Since methanol could dissolve brain lipids, its presence is undesirable. Researchers invariably make pure formaldehyde from paraformaldehyde added to 60ºC water and vigorously stirred, with sodium hydroxide (1N or 5N) added dropwise until cloudiness disappears (12, page 59).
Thorough fixation by formaldehyde can take many days (13, page 6) and, moreover, the crosslinks it forms are reversible, as opposed to the crosslinks formed by glutaraldehyde, which are irreversible (7). Glutaraldehyde fixation only takes a few hours (6, page 17), but the use of formaldehyde with glutaraldehyde is recommended because its perfusion rate is 2 to 6 times greater (14,15), and because glutaraldehyde has so much less capacity for preservation of lipids. Glutaraldehyde does have an ability to preserve phospholipids (by fixing their amino groups to tissue proteins), especially if calcium chloride is present (16, page 295). Glutaraldehyde also preserves biogenic amines (neurotransmitters) (15, page 35). Both formaldehyde and glutaraldehyde produce fixation more rapidly at a high pH, so this is another reason to keep the pH of the perfusion fluid somewhat basic. The exact percentage of each aldehyde to use is open to question. It would seem that high percentages would be desirable for long-term PCI preservation, but there are limits to how much aldehyde a perfusion mixture can maintain. Too much aldehyde may actually create a fixation barrier to perfusion. Experimentation would be useful, here. Polyvinylpyrrolidine (PVP 2%,ie, 2gm/100ml) is often added to these aldehyde solutions to improve fixation of regions of the hypothalamus and frontal cortex, where capillaries are of the blood-brain barrier (BBB) type (17,6).
Osmium tetraoxide (often called osmic acid) also has serious liabilities. It is very expensive, it has a slow rate of perfusion, and it coagulates (or gels) blood (12). Because osmium tetraoxide vapors are irritating and can cause corneal opacities, it should be used under a fume hood using plastic gloves and eye protectors (6). Although osmium tetraoxide does fix phospholipids by oxidation of double-bond carbons, a significant motivation for its use by ultramicroscopists is its staining properties (of little interest to cryonicists). Moreover, osmium tetraoxide is usually used for "postfixation", after the brain tissue has been removed from the perfused animal. Applied to small tissue sections, the blood coagulation, slow perfusion and tendency to form complexes with glutaraldehyde (15), of osmium tetraoxide are less problematic since the section can be perfused by immersion. Potassium dichromate in a 2-3% solution (2-3gm/100ml) has a very fast perfusion rate and reacts with phospholipids to make them insoluble in non-polar solvents (6,15). The value of dichromate as a perfusate constituent needs further assessment. Increased concentrations of formaldehyde and calcium chloride may actually provide the necessary lipid fixation.
One class of additives which it would be wise to avoid is cryoprotectants, which by their nature lower the freezing point of body fluids. Since dissolution of structure is far more dangerous in PCI than is deformation or breaking of structure, no lowering of freezing point is desirable. Moreover, cryoprotectants have toxic properties themselves which could be damaging to structures.
Good perfusion techniques may involve artificial respiration with 5% carbon dioxide/95% oxygen, and the use of heparin for anti-coagulation plus 1% sodium nitrite to produce vasodilation (12, page 57). The sodium nitrite should also assist long-term preservation for the same reason that nitrites are used in meats, by reducing the oxidizing effects of iron. BHT and other antioxidants could also be added.
The perfusate designed to preserve neural tissue described above, should be adequate for the rest of the body as well. It might, however, be a good idea to take tissue samples from other areas of the body and preserve them in a container of methanol (methyl hydrate, methyl alcohol), placed in a body cavity to ensure good preservation of some chromosomes (15, page 24).
It should be noted that current methods of preservation involving
embedding with paraffin or silicone-rubber tend to require the use of
organic solvents and lengthy exposure to high temperatures (18).
These methods are unsuitable for preservation of fine histological
structure, particularly in the brain.
Probably the most serious threat to long-term preservation is posed by water, especially in the brain where water concentration is high. Water allows for dissolution, hydrolysis and free-radical activity -- deadly and insidious over a 150-year time span. In a good permafrost burial, most water will be immobilized in ice. Also, formaldehyde is dehydrating in the sense that there is almost no free formaldehyde present in solution -- most formaldehyde is complexed with water to some degree or another, with the larger complexes actually precipitating-out as a powder, especially at low temperature (6, page 18). Other agents which form insoluble hydrates (besides formaldehyde) could be added. Even so, the presence of any water threatens loss of structure.
One solution to this problem would be to freeze-dry a cryonaut in a large freeze-drying apparatus at a low temperature. The vacuum of freeze-drying equipment would reduce the likelihood of tissue oxidation. Nonetheless, such a large freeze-dry unit would be expensive, and the process would probably take at least 6 months.
It would be far simpler if, after aldehyde perfusion, the brain could be removed and sectioned. In this case, the brain slices could be easily postfixed by osmium tetraoxide immersion and then freeze-dried in a small machine in a short period of time. If nanotechnology can repair freezing damage, then a sliced-up, fixed and dehydrated brain should pose no problem. Unfortunately, despite the possible economy and effectiveness of this procedure, it is so likely to be aesthetically offensive to many people that it could be a public relations nightmare, if attempted.
Freeze-drying machines are currently sold for taxidermy and to
dry flowers, herbs and vegetables. Units are sold by Vertis Company
in New York (914-255-5000) and by North Star in Nisswa, Minnesota.
The North Star representative, Steve Schuett (800-551-3223), told me
he would be quite willing to work with the American Cryonics Society,
and would provide free training.
The PCI cryonaut must be well protected from the elements, particularly from oxygen. A wax or plastic coating or even a spray-on material that hardens might provide good protection from oxygen. Jim Yount suggested Vaseline, which might not be such a bad idea considering that it would likely be harder and more waxy at permafrost temperatures. The problem is that the covering should not be so soft or fragile that it can be rubbed-off or broken-off in transport.
An ideal burial container would be like a Thermos bottle with a vacuum chamber between the cryonaut and the outer wall, so as to minimize temperature variations. A vacuum might be too expensive and difficult to achieve, but even an air chamber with silvered-walls would be useful. Expense of construction might still be prohibitive, in which case a tube which can be sealed at the ends would probably be best. This tube should probably be metal or hard plastic on the outside, to provide strength, and an insulating material on the inside, such as rubber and a sleeping bag, to minimize thermal conductivity. The cryonaut could even be placed into a vacuum-sealed plastic bag, inside the sleeping bag. The container should fit easily into a larger container which can be packed with dry ice for shipping.
David Henson (L5 Society) has suggested that a permafrost burial
container could be conjoined to a thermal diode. A thermal diode
would essentially be a tube -- filled with a substance having a very
low boiling-point -- which reaches from the burial container to the
surface. In the summer, the volatile substance would remain in a
gaseous state and would not (theoretically) conduct much temperature.
In the winter, however, the substance would condense at the ground
level and falling droplets would conduct low temperature down to the
burial container where they would boil, and thereby continue the
To assist the preservation by isolation from oxygen and by chemical preservation, the lower the permafrost temperature, the better. However, the absence of seasonal variation in temperature is also important, because even if the temperature is quite low, annual melting and recrystallization in local tissues could result in long-term histological pulverization (although this effect is difficult to quantify with currently available information).
The three locations under investigation for PCI have been Inuvik, Yellowknife and Resolute Bay, all in the Northwest Territories of Canada. Inuvik was the site of a permafrost burial in the Spring of 1988, and the funeral director, David Hansen, was very co-operative. Subsequently, he has received many inquiries from all over the world and he has been very eager to expand his business in this area. Indian land claims, however, have been a serious obstacle to further development. In early November of 1990, however, he told me that the Indian Land claims issue is close to being resolved and that the Indians themselves are quite interested in getting involved in the venture.
Most of the inquiries Hansen has received have not been from cryonicists. His biggest market seems to be wealthy people who want loved-ones preserved at low temperatures in glass cases for viewing. Hansen envisions subterranean rooms with display cases at costs that could range up to $125,000. Hansen would also service the needs of cryonicists, but he has not determined how much he would charge them. The Spring 1988 burial cost $4,000. Hansen's phone number is 403-979-3971. In Inuvik, seasonal variation is pretty well eliminated at a depth of 25 or 30 feet, and the average temperature would be -3ºC. At a depth of 10 feet, a seasonal fluctuation of 4ºC (-6ºC to -2ºC) could be expected.
In Resolute Bay, lands for burial and other uses are collectively owned by the Indian city council of that hamlet. Council meetings have addressed the issue of permafrost burial, and a wide range of opinion is expressed with little decisiveness. There is little enthusiasm for the commercial potential of PCI, and at least one council member expressed concern at the idea of their hamlet being turned into a big graveyard. Nonetheless, there seemed to be a willingness to co-operate with a few initial test cases. I was quoted a price of $1,200 by Mrs. Susan Sulluvinq (819-252-3616), the council secretary. This would not, of course, include shipping costs (there are regular flights from Edmonton, Alberta and Montreal, Quebec to Resolute Bay).
Seasonal variation at Resolute Bay is eliminated at a depth of 50 to 60 feet, and the average temperature would be -13ºC. At a depth of 10 feet, a seasonal fluctuation of 10ºC (-19ºC to -9ºC) could be expected. If economies of scale could justify it, a deep subterranean crypt with vaults for the insertion of cryonauts would be ideal. I doubt that there are any abandoned mineshafts in the Resolute Bay area insofar as permafrost probably makes mining prohibitively costly.
Yellowknife is in the region of discontinuous permafrost. Seasonal variation in temperature is eliminated at a depth of 25 or 30 feet, but this temperature is very close to 0ºC. Even temperature just above 0ºC would assist chemical preservation, but without ice formation, the presence of unfrozen water is a matter of concern, insofar as dissolution, hydrolysis and free-radical activity become more serious.
There appear to be no problems with Indian land claims in Yellowknife and the local funeral director, Yvonne Quick (403-873-5861) will co-operate in permafrost burial ($600 plus burial). In fact, the city works department is quite willing to sell gravesites to the American Cryonics Society.
Antarctica might seem attractive insofar as it is 11ºC colder on
average than the Arctic, but that continent, like Greenland, is almost
entirely covered by very thick ice. Alaska may afford some desirable
sites, but the best locations in the Northern Hemisphere are in
Siberia. A table of some of the record low temperatures at a variety of
locations gives an indication
of the worlds "coldspots":
(note -40ºF =-40ºC)
|LOCATION||FAHRENHEIT LOW||CELCIUS LOW|
|Plateau Station, Antarctica||-119.2ºF||-84ºC|
|Rogers Pass, Montana||-69.7ºF||-56.5ºC|
There is considerable concern that burial implies abandonment, which does not forbode well for reanimation. However, burial may simply be the cheapest and safest way of storing a body. Without burial, there must be a maintenance organization which can last 150 years and pay for the caretaking, storage and movement of bodies. Organizations of this nature are costly, vulnerable to failure and probably unnecessary. Moreover, burial allows the best access to permafrost temperatures with no maintenance cost.
To ensure that a gravesite is not lost, a large gravestone could be placed upon it. The gravesite could even be surveyed. Fred Chamberlain has suggested that magnetized poles be attached to the burial container to assist in locating it. The burial container itself should be engraved with information of use in identifying the person inside. Memorabilia and personal documentation could be included in the burial container.
Organizations also play an important role. They can store
documentation about the cryonaut's identity and location. And they
can maintain funds for reanimation. Reanimation funds could be in any
amount (no minimum). A cryonaut may choose to distribute such funds
to many organizations, for example Lifepact, the Reanimation
Foundation, the American Cryonics Society and the Cryonics Society of
Canada. If the American Cryonics Society deducted 20% of such funds
for research, improved methods of chemical preservation could be
developed initially, and methods of reanimation could be developed in
One of the selling points of PCI is the advantage of its use to provide an option for preservation of the remains of those who did not make arrangements well in advance of death. If PCI is low cost, then legal vulnerability is minimized because the procedure does not differ much from conventional embalming and burial.
Nonetheless, advance arrangements could still be of great value. Most significantly, these arrangements could expedite the speed with which chemical perfusion is performed following deanimation. A speedy release from a hospital would be ensured and possible issues related to opposition from certain relatives could have been addressed ahead of time. Expenditures for PCI and reanimation funds would have been pre-allocated and would not be part of a disputed estate.
The American Cryonics Society would take the leading role in providing PCI memberships. No other organization (to my knowledge) currently has the means or the eagerness to both make such arrangements and carry out the chemical perfusion -- certainly not the Cryonics Society of Canada. The Cryonics Society of Canada will be willing to store documents and to assist in making arrangements, where necessary, but it cannot independently offer PCI services now or in the near future.
Some suspension cryonicists may want to use PCI as a backup. To do so would mean that the initial perfusion would be with chemopreservatives rather than cryoprotectants. The implication of such an arrangement would be that if the liquid nitrogen suspension could not be maintained for political, legal or financial reasons, the cryonaut would be transferred from liquid nitrogen to permafrost.
Aside from studying the feasibility as thoroughly as I can,
neither I nor the Cryonics Society of Canada will do more than play a
supporting role in handling PCI cases. I do hope the American
Cryonics Society takes concrete steps towards making PCI an available
and workable option.
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One year ago the Winter issue of CANADIAN CRYONICS NEWS contained an article entitled "Possible Permafrost Burial Locations in Canada" -- which was a preliminary evaluation of the best possible Canadian Arctic sites for PCI (Permafrost Cryonic Interment). At the time that article was written, it was anticipated that progress would be made toward negotiating potential PCI sites within a few months. This assessment grossly underestimated the political problems. The formation of the new territory of "Nunavut" (meaning "Our Land" in Inuktitut, the language of the Inuit, and written: ) and the linkage of Indian land claims with the Canadian Constitutional Referendum (which failed last October) seem to be only the tip of an iceberg of problems. Decisions and resolution seem to move at glacial speed in the Canadian Arctic.
A plebiscite held at the beginning of November 1992 ratified the land-claim settlement which will establish the territory of Nunavut. Although 82% of Nunavut will remain Canadian Crown land, the Inuit gain mineral rights to 36,000 carefully-chosen kilometres in addition to title to the other 18% of the land. In 1999 a Nunavut legislature will be formed, after which a gradual transfer of power will occur, from the Canadian and Northwest Territories governments to the Nunavut government. Since the Inuit make up 85% of the 22,000 population of the region, Inuit political control is virtually assured. Nunavut will assume the powers of the other Canadian Provinces, while remaining under federal jurisdiction (as with the other Provinces).
The situation in the western Northwest Territories (which produces 75% of the NWT $2 billion gross domestic product) is a bit different. Although negotiations are in progress for a new political settlement, Aboriginals are divided amongst Metis, Dene Indians and Inuit -- and 53% of the population is non-native. Moreover, there is concern that the non-native population is growing faster than the native population.
The eight communities shown in the map of the Canadian Arctic are the only destinations for Canadian Airline cargo planes (the only common carriers making regular trips in the area which are large enough to carry coffins in shipping boxes). The map shows isotherms (lines) of mean annual air temperature in degrees Celsius. The significance of mean annual air temperature is that it corresponds closely to temperature at ground depths just below the level at which seasonal temperature variation ceases. I will briefly summarize my evaluation of each of these locations.
MAP OF POTENTIAL PERMAFROST SITES
was the site of the first Permafrost Cryonic Interment (PCI) (in 1988), although certainly not the first Inuvik burial. Inuvik has a funeral director, David Hansen, who arranged the PCI. Townspeople opposition to the use of their cemetery by outsiders, the high level of "politicization" of the PCI issue and Indian land claims seems to have stymied any potential for PCI in Inuvik for the foreseeable future.
this community is too small and to warm to merit much interest at this time.
was the site of the PCI in the Fall of 1990. Yellowknife has a funeral director, Yvonne Quick, who arranged the PCI. The European man who buried his chemically preserved grandmother in Yellowknife had been hoping to acquire title to the burial plot. The city of Yellowknife will not allow this, and the city retains ownership of the whole cemetery. This location is the least problematic of the eight communities, but it also has the warmest temperature.
is the most populous community in the Eastern Arctic, but it does not have a funeral director. Ownership of a cemetery plot in these Inuit-dominated communities is out-of-the-question, since even people who have houses must lease their land from the Indians. Burials are arranged by a Catholic and Anglican priest (the cemetery is divided into Catholic and non-Catholic sections), with the actual digging being done by inmates of the local correctional centre. The cemetery is close to full, and a Bylaw would be required to allow outsiders to be buried here. Residents are conscious of the political ruckus caused by the PCI in Inuvik. Marty Kuluguktuq, the man who wrote the Bylaw allowing non- resident burial in Resolute Bay, lives in Iqualuit.
is in the same legal jurisdiction as Frobisher Bay and Resolute Bay, so Marty Kuluguktuq would draft the required Bylaw for PCI if one was requested. (Marty seems quite co-operative in this regard.) Burials in Hall Beach are done year-round, but the locals content themselves with shallow graves (no more than a foot below the surface) because they only have shovels to dig with. PCI was evidently a topic on a local radio talk show, so people are prepared for the controversy, should serious requests be made.
is a mining town, with no indigenous population. Nanisivik Mines Ltd. is a subsidiary of Conwest Exploration Co. Ltd. (of Toronto), which has a lead-zinc mine on the north end of Baffin Island. The work is evidently seasonal, and if a worker died, he or she would be flown home. At some future time this site may provide the abandoned mine-shafts which are the dream of PCI enthusiasts who seek the ground depths necessary to escape seasonal temperature variation.
is the coldest of the eight communities. During a long period of indecision over whether to permit PCI, the Inuit council of Resolute Bay went so far as to pass the Bylaw required for burial of a non-resident. But after over six months of deliberation, the council voted against allowing the European seeking PCI for his grandmother, because he had not made a formal request in writing (he doesn't speak English). They may consider future requests if accompanied by a formal written request from a close relative of the person to be buried.
although well south of Resolute Bay, it still lies very close to the -15ºC mean annual air temperature isotherm that passes near Resolute Bay. Burials are only done in July, with cadavers awaiting burial (5 to 10 per year) stored in a shed. The non-native population of Cambridge Bay outnumbers the native population, and there is favorable interest in PCI. Nonetheless, approval must be gotten from the town council and the Department of Indian And Northern Affairs (DIANA). I have been waiting for a decision for over 8 months, and still seem to be no closer.
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Titanium is the only affordable metal with which one could build a secure time capsule which could reliably survive the millenia. Titanium comes in various grades which offer various levels of corrosion resistance. Grades 7 & 11 alloys which incorporate 0.15% platinum offer a performance in oxidizing acids which can only be beaten by precious metals themselves. Grade 16 with 0.05% platinum offers virtually the same performance at a significantly reduced cost. Grade 12 with 0.3% molybdenum and 0.8% nickel is the next step down, while grade 2 or unalloyed titanium is the least resistant. *1 However ALL titanium alloys including grade 2 have proven to be invulnerable to ALL ambient temperature ground waters including seawater. The most severe threats these fluids pose to metals is due to the presence of chloride and microbiologically induced corrosion (MIC). Grade 2 titanium is immune to both at ambient temperatures. *1 *2 The price of grade 2 titanium is also LESS than that of resistant nickel alloys. Thus the only materials which could offer a substantial degree of corrosion resistance at a price significantly lower than titanium are the stainless steels.
Unlike titanium alloys, stainless steels exhibit a very wide range of corrosion resistances because of their large differences in composition. However all derive their resistance from a microscopic surface layer of a brittle ceramic composed of chromium oxide, which forms on steels alloyed with at least 12% chromium. Better grades of stainless have chromium contents ranging up to 30% as well other alloying additions which help to stabilize the chromium oxide layer. Additions which are generally helpful in this regard include molybdenum, nitrogen, tungsten, silicon and vanadium. *3 The later three additives see little use since tungsten is relatively ineffective in raising corrosion resistance, silicon makes the alloy brittle while vanadium is simply too expensive. Up to 6% molybdenum and 0.4% nitrogen are commonly used to help stabilize the chromium oxide layer, though new experimental alloys with higher nitrogen contents are under development. Copper has been found to possess a synergism with nitrogen, possibly because it tends to inhibit the formation of chromium nitride inclusions. *6 *7 Recent research has also found that phosphorus has a dramatic effect in increasing corrosion resistance, though no commercial alloys as yet contain deliberate phosphorus additions. *4 *5 Some minor constituents of stainless alloys such as sulfur also have been found to be detrimental since pitting tends to initiate at manganese sulfide inclusions. *6 Calcium treatment of the melt has been found to eliminate these inclusions and significantly improve both corrosion resistance as well as low temperature ductility. *8 *9
The least expensive stainless steels are the 12% chromium steels such as 3CR12. The most common stainless steel (used for cutlery) is type 304 which possesses 18% chromium, 8% nickel and a price tag double than of 3CR12. With the further addition of 2.5% molybdenum we have type 316, which is twice as expensive as type 304. Increasing alloying additions to 6% molybdenum, 0.2% nitrogen and 18% nickel we have 254SMO, which is (you guessed it) twice as expensive as type 316. With 254SMO we are starting to get close to the price of grade 2 titanium so if we are to consider such an alloy as a replacement for titanium it had better be good. It isn't. Although 254SMO has a high resistance to chlorides it has experienced a few failures due to MIC. *10 The reason for this appears to be related to the harmful effect that additions of over 2.5% molybdenum have on resistance of stainless steels in some highly oxidizing acids. This is further supported by the fact that pickling stainless steel welds to increase their surface chromium content and render them resistant to highly oxidizing acids also renders them invulnerable to MIC. *11 Although the details of the corrosion mechanisms involved in MIC are still not yet fully understood we can be reasonably certain that an increased chromium content coupled with a more modest molybdenum content would likely offer an improved resistance to MIC. (Nitrogen is neutral with respect to highly oxidizing acids.)
An example of such an alloy is SAF 2507 with 25% chromium, 3.8%
molybdenum, 7% nickel and 0.27% nitrogen. In addition to (we believe)
not being susceptible to MIC, this high strength alloy is also less
expensive than 254SMO because less of this alloy is required for
structural applications to obtain the same yield strength. Such high
strength stainless steels currently offer the only reasonably
convincing lower cost alternative to titanium. To further cut costs
the nickel content of many of these alloys has been reduced so that
low temperature ductility suffers. However a similar but cheaper
alloy SAF 2205 has been selected for use in pipelines in the arctic
and since SAF 2507 itself has a similar impact toughness this would
seem not to be a serious defect. *12 In any case high strength
stainless alloys with an increased nickel content such as Remanit
4565S are starting to become available on the market as well. *13
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(reprinted from the September 1993 Funeral Service Journal UK)
Encasing metal caskets in plastic is by far the most cost effective method for increasing the corrosion resistance of the casket. For example although aluminum readily corrodes in many soils the application of thin 0.25 millimeter plastic tapes on aluminum pipelines in Canada eliminated all leakage failures over a 25 year period. *1 By comparison upgrading to a more expensive alloy alone can be a relatively ineffective means for increasing corrosion resistance as low cost stainless steel sheets have been found to perforate in high chloride soils in less than 4 years. *2
A case could be made for including a stainless steel cladding as part of a more comprehensive barrier system. Applying plastic directly to stainless steel is not cost effective since inexpensive grades of stainless steel are susceptible to chloride induced crevice corrosion under the plastic. Fortunately concrete coatings do not seem to suffer from this defect.
When steel, galvanized steel, epoxy coated steel and stainless steel were embedded for 7 years in concrete contaminated with low ,medium and high amounts of chlorides the results were instructive. Both steel and galvanized steel rapidly corroded and cracked the concrete at all chloride levels. The plastic coated steel faired much better as no corrosion was observed in low and medium chloride concrete, but extensive corrosion and concrete cracking did occur in the high chloride concrete. Curiously the stainless steel remained inert at all levels of chlorides. *3 How expensive does stainless steel have to be to be immune to chlorides when embedded in concrete? The answer is surprising. Even (12% chromium) 3CR12 stainless cladding has been found to be fully immune to corrosion due to chlorides when protected by the alkaline pH found in concrete. *4 Thus it seems that ALL grades of stainless steel, including even the cheapest are not susceptible to corrosion when embedded in concrete.
A 3CR12 clad steel casket will almost certainly remain inert for as long as the concrete it is embedded in lasts. How long could this be? Concrete can be damaged by freezing, but by including sufficient air entraining agent in the mix to help trap some air in the matrix freezing damage is virtually eliminated and thus is not a significant concern. *5 In contrast to steels concrete itself is not particularly sensitive to chlorides. Instead it is primarily sulfates which destroy the cement paste which binds the concrete aggregate together. Cements like steels are marketed in various grades which vary greatly in their resistance to chemical attack. By lowering the tricalcium aluminate content sulfate resistance of portland cement is significantly increased. The addition of pozzolanic materials such silica fume, fly ash or blast furnace slag reduces the permeability of cement by several orders of magnitude and thereby further improves chemical resistance. *6 Even unalloyed steel is virtually immune to chloride induced corrosion when it is embedded in an advanced pozzolanic blended cement as chlorides cannot readily penetrate this type of cement. *7 One might further improve matters by incorporating a corrosion inhibitor such as calcium nitrate in the cement and then sealing the concrete block itself with epoxy. *8 *9
How long could a 3CR12 stainless steel clad casket last if it was embedded in an epoxy sealed concrete block, which was then placed in a (crowded) coffin and buried in a cemetery? We can get an idea by observing that ancient Roman cisterns made with a high quality "waterproof" plaster still hold water 24 centuries later. *10 The lifetime of the proposed construction would probably likewise be measured in centuries.
A final tip for the interested: Unlike more costly stainless
steels 3CR12 welds show maximum corrosion resistance when air cooled,
rather than when quenched with water. *11
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Thus far there have been three permafrost burials in Canada for the purpose of biostasis, one in Inuvik and two in Yellowknife. Local disputes and land claims issues prevented further burials in Inuvik for quite some time after the 1988 burial. But a year ago, according to Richard Helm of THE EDMONTON JOURNAL, the Inuvik authorities amended their burial policies to allow non-resident burials for Cdn$14,800. Needless to say, this undermines the economy argument for permafrost burial.
The two burials in Yellowknife were both Europeans who had been chemically preserved and well-sealed. Although Yvonne Quick of Yellowknife handled the burials, she did not send the proper legal documents -- or any documentation whatsoever to the relatives in Europe. I wasted a great deal of time and money phoning and writing Yvonne Quick asking for documentation. Each time she assured me it was forthcoming. Each time, nothing came. I began to think that this woman must be a pathological lier. Nonetheless, a CSC member travelled to Yellowknife and personally examined the graves. And the appropriate documentation was eventually sent by Yellowknife civil servants.
Although there have been many problems with every potential burial location identified in the NorthWest Territories, Resolute Bay (the coldest spot) is still potentially available. The Bylaw is in place for burial of a non-resident, and the city council will seriously consider a letter of request from an immediate relative.
As a possible alternative -- and to avoid Indian land claims issues, I have done some investigation outside the NorthWest Territories. I examined Churchill, Manitoba; Whitehorse, Yukon and Fairbanks, Alaska.
Churchill, Manitoba is actually colder than Yellowknife, and it is accessible by train or plane (but airplane is cheaper). A cemetery plot is Cdn$500. Northland Funeral Services [(204) 778-7982] can arrange to clear customs in Winnipeg, Manitoba and handle shipping and burial thereafter for under Cdn$1,000. Transportation may be extra.
Whitehorse, Yukon is at the lower border of the discontinuous permafrost line, but burial there should not be difficult. Yukon Funeral Services [(403) 668-2750] will handle the burial for Cdn$800 once the casket arrives in Whitehorse from Vancouver, British Columbia.
Fairbanks, Alaska has two funeral services: (1) Chapel Chimes [(907) 452-1053] and (2) Alaska Memorial [(907) 452-1053]. Alaska Memorial is a privately owned cemetery which charges US$530 for a grave plot, US$50 for perpetual care, US$495 interment fee and US$110 for pickup from the airport. A US$585 vault is required. Chapel Chimes handles the city cemetery.
Burrow, Alaska has a population of 2,104 and a mean annual temperature of -9ºC. College, Alaska is near Fairbanks and has a population of 3,434. The coldest regions in Northern Europe are all discontinuous permafrost. The only continuous permafrost in Russia is in Siberia -- the coldest regions in the Northern Hemisphere.
Low temperature burial sites in North America are available. Chemical preservation, isolation from air & moisture and perhaps dehydration are at least as important as low temperature. Permafrost temperatures alone are surely not very effective at preserving biological structure. I hope to spend less time in the future searching for inexpensive and accessible low-temperature burial sites -- and more time contributing to methods of biostasis which could be an alternative to liquid nitrogen storage.
ALASKA PERMAFROST MAP
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Fueled by curiousity I decided to pay a visit to Yellowknife. Ben Best had a job for me as well. "Your mission should you decide to accept it is to photograph the graves of two Europeans buried in the permafrost. Their relatives would really appreciate this." Then the tape recorder burnt itself out.
After an inexpensive charter flight to Edmonton I was surprised to learn that plane fare between Edmonton and Yellowknife was a rather hefty $600 return. So I made the mistake of hopping on a milk run Greyhound bus bound for Enterprise, NWT instead. I had had flap jacks for breakfast and had forgotten them till the road became rather rough and the bus started going up and down, up and down. The flap jacks started going flip, flap, flip, flap. At the Alberta border there was a sign stating that all the land beyond was the North Western Territories. It looked like the end of the universe to me at the time. Eventually the bus stopped shaking. I looked out and spotted a diner stuck out in the middle of nowhere. This was Enterprise, the home for 49 people and my bus stop. Heaven I thought. The air had quite a chill in it for early October and the trees looked rather runty. I sat down and waited. The wind whispered its secrets for a time. A loud flapping noise startled me. It was a raven flying overhead. One forgets how quiet nature can be after living in a city for so long. The last leg of the journey to Yellowknife turned out to be a bus from Arctic Frontier Carrier. The bus driver put out his hand and a fifty dollar bill disappeared from my wallet and appeared therein. However this bus driver drove more slowly and the ride was rather more smooth.
After arriving late in Yellowknife I flagged a taxi and hopped in. The driver was a black fellow who seemed very enthusiastic about all the money non-natives were making in Yellowknife and all the alcohol the natives were drinking and what was I doing in Yellowknife? Fare was $4. I handed him a ten and received $104 in change. After handing back the hundred I looked at him and wondered and wondered.
Next day I visited Lakeview Cemetery with Brian, the grave digger to guide me. The new section of the cemetery had two graves that did not have any headstones on them, but instead had sections of black ABS pipe sticking out of the ground. Paupers I thought, surprised that this was even allowed in a modern cemetery. Brian pointed to one of the unmarked graves and indicated that this was one of the plots I was looking for. This did not make any sense as the family must have spent a lot of money just shipping the casket across the Atlantic Ocean to Canada. They had money all right. Brian was not sure where the other was buried so he called in the foreman. Surprise, surprise the other unmarked grave was the other European. I took photographs of what there was in the area, including the surrounding "forest". A forest this was if you agree that trees 15 feet tall can be called trees rather than shrubs.
Later I visited the Yellowknife Public Works department to fish for more information. Cheri Ducept, the secretary mentioned that a bylaw is being considered to require all graves to have a headstone. She also mentioned that burying the Europeans was quite a lot of trouble as their caskets were far larger than is normal. One of them even had a thermometer sticking out of it. A bylaw requiring that foreigners pay extra for burial is being considered she noted.
Cheri had been informed by Territorial Funeral Homes that one of the Europeans had apparently been first shipped to Rankin Inlet for burial in the permafrost, but the local native Indians had refused to allow burial in their cemetery. Territorial Funeral Homes became involved and the casket was shipped to Yellowknife for burial. According to Brian in May you hit frost about 4 feet deep in Lakeview Cemetery, but by October this is 8-10 feet deep if there is any permafrost at all. The graves of both Europeans were of the standard depth of 6 feet, so they are not situated in permafrost. I asked if there was a colder cemetery in the Yellowknife area and was told that there was an older one, but it suffered from a lot of ground water runoff and at least one buried body had resurfaced as a result.
I spent the rest of the day touring Yellowknife and marvelling that it could have highrises this far north. It is a "working" town and not a tourist attraction, unless you are hunting big game or diamonds. Nonetheless there was a very nice tourist information center. There I learnt that almost 17,000 people lived in Yellowknife, that the average household income was $66,800 and that food prices were 37% higher than in Edmonton. I wondered what the average native Indian household income was. Normal temperatures for Oct 6th were 4 to -2ºC. This year was warmer with a range of 6 to 2ºC. Record high of 16ºC was in 1988. Record low of -10ºC in 1979!
I decided to make one last visit to Lakeview Cemetery. I purchased a flashlight and shone this down the two ABS pipes on the graves to see if I could spot a thermometer. The pipes curved however and nothing was visible inside them. After arriving back in town I phoned Territorial Funeral Homes and ordered two brochures on headstones and grave caps be mailed to my address so I could forward these on to the parties concerned. The secretary Milly Pittner seemed to be all business where potential sales were at stake. She mentioned that the funeral director was Robert Jensen. If there are any further dealings with Territorial Funeral Homes regarding permafrost burial I recommend that all correspondence be with with Robert.
After this business I took one last look around downtown
Yellowknife. Then I left.
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I have explored the feasibility of alternatives to cryopreservation with specific emphasis on a program which would attempt to combine: (1) chemical preservation, (2) isolation from oxygen, (3) dehydration and (4) permafrost burial. Of these, isolation from oxygen has been sadly de-emphasized despite the remarkable preservation which has been achieved for insects in amber.
In 1984 researchers at the University of California -- notably Allan C. Wilson and Russell Higuchi -- published a preliminary report of isolation of DNA from 40,000 year-old mammoth tissue and from an extinct zebra-like horse (quagga) [FEDERATION PROCEEDINGS 43:1557 (1984)]. Shortly thereafter they published a paper detailing the sequencing of DNA extracted from 140-year-old salt-preserved quagga tissue -- with a yield of approximately 1% what would be expected from fresh muscle tissue [NATURE 312:282-284 (1984)]. The next year Svante Paabo of Sweden produced a yield of DNA from a 2,400 year-old Egyptian mummy that was nearly 5% of what would be expected from fresh tissue [NATURE 314:644-645 (1985)]. Skin tissue in direct contact with dehydrating agent (natron) had the best preserved DNA.
Five years later, however, Edward Golenberg of Wayne State University reported extracting DNA from a fossilized 17 million-year-old magnolia leaf found in a deep fresh water lake [NATURE 344:656-658 (1990)]. Within two years this record was broken by a reported extraction of 25-30 million-year-old DNA from a fossilized termite preserved in amber by David Grimaldi's team at the American Museum of Natural History [SCIENCE 257:1933-1936 (1992)]. One year later, even this record was smashed by a report of DNA extracted from a 120-135 million-year-old weevil from Lebanese amber by California scientists Raul Cano and George Poinar [NATURE 363:536-538 (1993)].
In 1990 -- before scientific reports of success in finding DNA in amber-fossilized insects -- Michael Crichton had published the novel JURASSIC PARK about reconstruction of dinosaurs from DNA cloned from dinosaur cells found in blood-sucking insects preserved in amber. The novel became a smash-hit movie. George and Roberta Poinar published the book THE QUEST FOR LIFE IN AMBER (1994), which popularized the scientific basis for studying life preserved in amber.
In 1997, however, more careful scientific work cast all reports of multi-million-year-old DNA in a more doubtful light. The cornerstone of these DNA studies has been Polymerase Chain Reaction (PCR), an extremely sensitive scientific procedure in which tiny bits of DNA are multiplied ("amplified") millions of times, as with a "genetic photocopier". Contamination of samples has been extremely difficult to avoid. The most modern equipment and careful science of 1997, in attempting to reproduce many earlier DNA discoveries, has resulted in negative findings.
Presumed dinosaur DNA from Cretaceous bone fragments was shown to be due to human contamination. And presumed dinosaur DNA from a dinosaur egg fossil was shown to be from fungi [MOLECULAR BIOLOGY AND EVOLUTION 14(5):589-591 (1997)]. Many attempts to replicate DNA extracted from insects in amber under the most careful conditions has produced negative results [PROCEEDING OF THE ROYAL SOCIETY OF LONDON: BIOLOGICAL SCIENCES 264:467-474 (1997) and MOLECULAR BIOLOGY AND EVOLUTION 14(10):1075-1077 (1997)]. The oldest independently verified DNA extraction (from mammoth bones, etc.) is less than 100,000 years old.
Leaves and dinosaur remains had been exposed to water & oxygen. There are sound theoretical reasons for believing that DNA could not survive hydrolysis & oxidation under such conditions for more than 50,000-100,000 years [NATURE 365:700 (1993) and NATURE 366:513 (1993)]. Preservation in amber is another matter, however. Despite the current funk about DNA from insects in amber, there can be no question of excellent preservation of tissue ultrastructure -- including ribosomes, endoplasmic reticulum and mitochondria -- for tens of millions of years [SCIENCE 215:1241-1242 (1982) and SCIENTIFIC AMERICAN 274(4):85-91 (1996)].
Tree sap (resin) contains sugars as well as alcohols & aldehydes (including terpenes), which are dehydrating & antibiotic as well as providing an air-tight seal to prevent further entry of oxygen. Myrrh is a mixture of resin, gum and essential oils from the Commiphora plant that was used by the ancient Egyptians for embalming (by pouring it into the cranial, chest, abdominal and pelvic cavities) and mummification (by soaking the wrapping bandages in it).
Despite the discovery of lucite & epoxy resins, it has not yet been possible to artificially synthesize amber, the hardest natural resin known. A major component of amber, however, is terpene, a class of hydrocarbons of the general formula (C5H8)n -- polymers of isoprene units. Turpentine is a mixture of low molecular weight terpenes (18% of the sap of living pine), whereas the latex of the rubber tree consists of high molecular weight terpene polymers where n=4,000-5,000. Carotenoids (like lycopene and beta-carotene) are built from isoprene units, but have the formula C40H56, rather than C40H64 -- due to unsaturation.
Amber, as a sticky pitch from certain trees, can trap insects when fresh from a tree-wound. The sugars, alcohols & terpene-aldehydes diffuse into the insect to dehydrate & preserve. The amber surrounds the insect, providing an air-tight seal. Further oxygenation & polymerization of the terpenes protect the insect from further damage. The continued polymerization of the amber terpenes eventually results in an insoluble gemstone-quality glass that preserves the insect in a strong encasement. Although such fortuitous combination of chemical preservation and oxygen-tight encasement should not be expected for preservation of large specimens (like humans), the use of some hardened plastic or resin encasement for protection from oxygen seems advisable.
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