Tuesday, November 25, 2008

HEALTH-RISK PERCEPTIONS TRUMP SCIENCE

What is objectionable is that these voluminous and authoritative-appearing documents convey the message that passive smoking is a major cause of fatal disease, which few scientists believe to be the case. -– Geoffrey C. Kabat

It’s a thrill when the author of a new book also served as an expert on a policy-making report with which one is familiar. The subject is ETS, environmental tobacco smoke (i.e., secondhand smoke or passive smoking). The EPA with the help of its Advisory Board in 1992 published its Report which found a very low relative risk of 1.19. It listed ETS as a Class A human carcinogen, which scientists believe it is not. That is the conclusion EPA intended to reach from the beginning, declared Federal District Court Judge Osteen, who discussed at length the Report’s plethora of errors.

The unique, excellent new book is Hyping Health Risks, Environmental Hazards in Daily Life and the Science of Epidemiology (Columbia University Press, 2008). The author, epidemiologist Geoffrey C. Kabat, was a member of EPA’s Science Advisory Board (though he barely mentions it) for ETS, Environmental Tobacco Smoke. His book covers four case studies of lung-cancer deaths: ETS, breast cancer, radon, and electromagnetic fields from power lines and household appliances. In this column we deal at length with ETS and radon in residences.

Kabat takes each case from its initial stage of “emergency! health scare ahead!” through subsequent studies to ascertain whether the health risk is real. It is important, as there is always a health risk-du-jour. Examples: The Natural Resources Defense Council asserts that chemicals used in shampoos are “neurotoxins” which cause seizures, and it wants FDA to ban them; the National Christmas Tree Association claims that artificial trees “harbor cancer-causing and poisonous chemicals,” and it wants FDA to ban them; Mayor Bloomberg wants transfats in restaurant food banned.

Hyping Health Risks fills a knowledge gap between scientists and lay readers, making the complex understandable. It has a Glossary. If you want to know what ionizing radiation is and nothing you have read ever stops to explain it, Kabat has it in his Glossary. And so too for the very important “statistical significance,” LNT (EPA’s linear-no-threshold hypothesis), odds ratio vs. relative risk, ELF-EMF (extremely low frequency electromagnetic fields), &ca &ca &ca. All are there and more.

EPA’s 1992 Report on ETS concludes that ETS causes lung-cancer deaths. Kabat goes back to the 1970s when two Harvard scientists, to evaluate the perception that ETS is dangerous, set about to measure it in public places. They found only a tiny amount, the equivalent of 0.004 (four one-thousands) of a cigarette per hour, and the equivalent of smoking seven cigarettes a year. This definitive study was completely ignored, the fund-grantor, Massachusetts Lung Association, even refusing to publish it. But it was published, then ignored. “People had already made up their minds that smoking and smoke were bad, and would not accept anything to the contrary,” author First told Kabat. Perception trumped science.

Kabat takes us through a second study of exposure to ETS. Subjects wore close to their bodies equipment measuring exposure to ETS in their home, and a second gadget for use when at work in their home. They measured approximately 8-10 cigarettes’ worth of nicotine and particles annually.

Radon is said to be the second most important cause of lung-cancer deaths. Information on radon comes from miners who worked for years in underground mines, and who smoked. The goal was to extrapolate down to what happens with a much smaller exposure of radon in residences. EPA estimated that from 6,000 to 36,000 lung-cancer deaths a year come from radon. But 90 percent “are likely to occur in smokers and would not occur in the absence of smoking,” says Kabat who adds, “It should be possible to acknowledge that much is known about the effects of radon at high levels encountered in mines but that we cannot characterize the risk at the very much lower levels typical of homes.”

EPA, whose philosophy is that there is no safe level of any carcinogen, makes assertions about strong radon threats which have no scientific basis. “We’ve created a statistical illness, multiplying a very small risk by a very large population to come up with frightening figures,” observed expert Ernest Letourneau.

As with radon, serious studies of electromagnetic fields and breast cancer so far have not found explanations, and the public is dissatisfied, frustrated, and inclined to believe the hype.

Explained authors Poole and Trichopoulos of an electromagnetic field study, “We have never stated that a causal association between EMF and cancer is impossible. We have indicated that the evidence for such an association is empirically weak and biologically implausible. We have never proposed that research concerning the health effects of EMF be discontinued . . . [W]e believe that . . . there are currently more serious health needs that should be given higher priority".

By Natalie Sirkin
c2008
Natalie Sirkin ;
Post a Comment