Responding to “No Safe Dose” Revisited: That Is Not What Regulators Thought at the Time

Some time ago we posted on the topic of responding to the inevitable contention from plaintiff counsel that there is “no known safe dose of asbestos” or its frequent companion “every major health agency says there is no known safe dose.” These arguments are repeated as if they support the conclusion that since there was no known safe dose, every health agency always agreed that any dose was UNsafe. One of the thrusts of the earlier post was to point out that while the current scientific thinking might be that a safe dose has not been demonstrated, that was not the thinking of scientists and regulators in past years when exposures were actually occurring. As discussed before, throughout the 1950’s and 1960’s the State of California was stating that it had established a safe dose and it was at a level of 5 million particles per cubic foot as an 8 hour time weighted average over an entire career. We now cite to additional publications that there never was a consensus that any and all doses are unsafe.

Perhaps it should not be surprising, but the source is the United States Public Health Service. In January 1963 the USPHS announced its intent to conduct a large survey of asbestos exposures and hazards in workplaces. While the USPHS acknowledged that hazards associated with asbestos exposures had been known for years, it also noted that “many questions remain unanswered—.” In addition to seeking to answer the question “Are malignancies occupational risks of the worker in the asbestos product industry?,” the USPHS asked: “What are the safe levels of exposures to the various materials that constitute health risks in this industry?” (emphasis added.)

This same study is discussed again in a publication from the USPHS that was presented at an International Congress on Asbestosis in Caen, France in May 1964. The authors are identified as L. Cralley, H. Ayer, P. Enterline, A. Henschel and W. Lainhart (all identified as Chiefs or Assistant Chiefs at the Department of Health, Education, and Welfare at the Public Health Service, Division of Occupational Health). They outline their plans to conduct a broad study at numerous sites to collect and analyze data. “There is a great need for further definitive information on the health effects from exposure to asbestos dusts and fibers and on safe levels of exposure.” (emphasis added.)

This same thinking prevailed in the USPHS for at least several more years. In April 1967, Dr. Cralley circulated a draft of a paper reviewing what had been discussed at a USPHS sponsored meeting in Cincinnati in 1966. The draft paper comments that “Even though asbestos has been in industrial use for well over 50 yrs, much is unknown regarding its health effects and safe levels of exposure.” (emphasis added.) At this time, the prevailing standard was the Threshold Limit Values published by the American Conference of Governmental Industrial Hygienists at 5 million particles per cubic foot as an 8 hour time weighted average over a career. One of the threshold issues for which the attendees at the conference are reported to have sought an answer was “What levels of exposure to the etiologic agents associated with asbestos-related diseases can be regarded as safe.” The paper goes on to state: “This is the prime objective of the research. When information on safe levels becomes available, environmental and other controls case be devised to keep exposures within the recommended limits.”

In 1969 Dr. Cralley, Dr. W. Clark Cooper, Dr. William Lainhart and Dr. Murray Brown published a paper in the Journal of Occupational Medicine. The authors again outline the many issues yet to be understood in regards to the health risks associated with asbestos exposure. Contrary to what plaintiff counsel repeatedly try to persuade jurors, at that time knowledge about asbestos hazards was far from complete and many conclusions argued to be established today were still very unsettled then. This paper recognized that one of the issues to be resolved was “[w]hat levels of exposure to the etiologic agents associated with asbestos-related diseases can be regarded as safe.” (emphasis added.)

Plaintiff counsel want the jurors to believe that since their experts will say that no one has yet proven that there is a “safe” level of exposure to asbestos (as if that could ever be done), that means that every exposure to asbestos is known to be unsafe. And to imply that such has been the accepted thinking for decades. That is manifestly untrue. As the citations above and other evidence demonstrates, during the pertinent time in the 50’s and 60’s when many of the claimed exposures were occurring, representatives of the USPHS and other researchers and scientists felt that they did not have adequate information to answer many questions about hazards from asbestos. They felt that collecting more data would allow them to identify a safe level. They did not claim at that time, nor do competent researchers and scientist today claim, that every exposure is hazardous. The corollary is that companies using asbestos and manufacturing asbestos products were not on notice that every use of asbestos was unsafe. To the contrary, they were being told by the State of California, the USPHS and others that controlling exposures to the existing regulatory limits would be safe.