The Disappearing Blog on Chrysotile Asbestos

The Failure of Science

Having completed my last two Blogs on Crocidolite Asbestos and Amosite Asbestos, both within the amphibole family, I was going to finally address the history surrounding the serpentine Chrysotile Asbestos. However, having again reviewed the historical science, I have decided to pass rather than to delve into science mixed with politics.

I don’t meant to pass on discussing the historical uses of chrysotile as that is easy and not very controversial. Chrysotile Asbestos was about 95% of the asbestos in commercial use over the years and was incorporated into thousands of products. The best discussions on the wide scope of the products using Chrysotile Asbestos fibers are contained in two books, one from 1963 entitled Asbestos Fundamentals and one from 1966 entitled Asbestos with Plastics and Rubber. Both books are only about 150 pages and relatively easy reading. Let me know if you would like to borrow them.

In addition, Chrysotile Asbestos is the only asbestos still in large scale commercial use. The 2020 Minerals Yearbook published by the U.S. Geological Survey shows mine production in 2018 at 1,150,000 tons and in 2019 at 1,100.000 tons, primarily from Russia, Kazakhstan, China, and Brazil (although Brazil is now out of the asbestos mining business). The largest importers are India, Indonesia, China, and Uzbekistan.

My issue with delving into the science is more pragmatic. Science, in spite of the best efforts of some very bright people, has historically failed when it comes to asbestos. As a simple example, until the mid-1930s, scientists and their textbooks routinely used the wrong formulas for amphiboles. For Tremolite Asbestos during that time frame, the formula was stated in textbooks as CaMg₃(SiO₃)₄ while an analysis easily available at the time calculates it precisely and accurately as Ca₂Mg₅Si₈O₂₂(OH)₂; not even close. As stated in Dana’s:

“It is little wonder that the chemistry of the silicates was regarded as a chaotic morass of uncertainty.”

If you cannot get the chemistry correct, then its pretty difficult to understand the mineral and its potential hazards. For more details on these types of issues, please see Dana’s Manual of Mineralogy, 17th Edition starting at page 393.

And, there lies the issue with science about chrysotile. Most, if not all, of the testing involving Chrysotile Asbestos involved fibers contaminated or polluted with some degree of amphibole asbestos. In addition, at least in the United States and Canada, much of the science is led by experts with vested interests either on the Plaintiff side or the Defendant side. When you read the studies, they involve those two camps of scientists throwing stones at each other more than discussing solid, peer review studies on exposure issues regarding pure Chrysotile Asbestos fibers. I suspect that they each believe what they are saying, but there is no way to reconcile the opinions of these highly trained, extremely smart people who are actively engaged in this issue.

It isn’t just the scientists. The Environmental Protection Agency just came out in December 2020 with their 352 page risk analysis for Chrysotile Asbestos. However, the EPA made clear that their analysis involved chrysotile contaminated with some degree of amphibole asbestos fibers and not pure chrysotile. Why? Because trace amounts of amphibole forms of asbestos “may” remain in chrysotile as it is used in commerce. “May”, not will, no discussion on why, no evidence to show when. See the Report at page 23 of 352, lines 52-54. In addition, the EPA on page 37 of 352, lines 594 to 602 makes clear that the reasonably available epidemiologic studies include populations exposed to chrysotile fibers potentially containing small but variable amounts of amphibole asbestos. The EPA repeats the same proviso on page 153 of 352. As such, nothing in the 352 pages really helps on pure Chrysotile Asbestos.

We all could likely have saved the EPA 351 of their 352 pages by agreeing that any substance contaminated with amphibole asbestos is dangerous.

So, here is where I come down should you come across a situation of potential exposure. Unless or until better chrysotile studies are undertaken and peer reviewed, then you should presume that all asbestos is hazardous and a health risk to you. It doesn’t matter what name is given to that health risk, whether Mesothelioma or Lung Cancer, or the degree of exposure, all that counts is the existence of a risk which you can avoid.

A good summary is provided by the World Health Organization in its 2014 publication on Chrysotile Asbestos as follows:

“Exposure to asbestos, including chrysotile, causes cancer of the lung, larynx and
ovary, mesothelioma (a cancer of the pleural and peritoneal linings) and asbestosis
(fibrosis of the lungs) (5–7).

Asbestos (actinolite, amosite, anthophyllite, chrysotile, crocidolite and tremolite) has
been classified by the International Agency for Research on Cancer as being carcinogenic to humans (7). Exposure to chrysotile, amosite and anthophyllite and to mixtures containing crocidolite results in an increased risk of lung cancer (7). Mesotheliomas have been observed after occupational exposure to crocidolite, amosite, tremolite and chrysotile, as well as among the general population living in the neighbourhood of asbestos factories and mines and in people living with asbestos workers (7).

The incidence of asbestos-related diseases is related to fibre type, size and dose and
to industrial processing of the asbestos (6). No threshold has been identified for the
carcinogenic risk of asbestos, including chrysotile (5, 7). Cigarette smoking increases
the risk of lung cancer from asbestos exposure (5, 9).“

Further, from the April 23, 2019 Australian Government Fact Sheet:

“Even a basic appraisal of the most recent primary scientific literature confirms the overwhelming evidence that asbestos—including chrysotile—is a major health concern, causing devastating disease on a global scale, from historic as well as current exposures in the workplace, in public buildings such as schools and hospitals and in non-occupational settings like homes.“

Some day, we may see better testing. But, until that day, better safe than sorry.

Let me know in the comments or by email to TheAsbestosBlog@gmail.com your thoughts on this topic.