Monday, November 15, 2010

New study: No evidence linking SHS and lung cancer

“There's no safe level of exposure.” That's the oft repeated mantra of anti-smoker zealots warning of the alleged dangers of secondhand smoke exposure. The quote, attributed to former US Surgeon-General, Richard Carmona, is usually expressed with all the reverence due a religious text.

The evidence is conclusive; unambiguous; proven beyond a reasonable doubt . . . or so say the zealots. But what's the scientific reality?

A new Canadian study finds no evidence that exposure to secondhand smoke contributes to lung cancer. The study, conducted in Toronto, Ontario, states: “Among never smokers in our population, we observed no association between either exposure to ETS at home or at the workplace and lung cancer risk.“

The study, was published online, at BioMed Central, in June of this year. The authors included researchers from several prestigious organizations, including the University of Toronto Faculty of Medicine, Princess Margaret Hospital (Toronto's most well known cancer treatment facility), Women's College Health Research Institute and Mount Sinai Hospital Family Medicine Clinic, all based in Toronto.

A study from such reputable sources must have generated a fair amount of media attention, at least here in Canada. Right? And, perhaps it did.

But, if it did . . . well , maybe “I got stoned and I missed it”, to quote an old song by Dr. Hook and the Medicine Show from back in the seventies.

At any rate, I didn't hear about the Canadian study until I followed a link to a Danish blog a few days ago. Uh-huh. I had to go half way round the world to find out what's happening in my own back yard.

The blogger, journalist Klaus Kjellerup, quotes lead author of the study, Darren Brennner of the University of Toronto: "Passive smoking at home and at work has been investigated in numerous studies, but results have been small and insignificant. A meta-analysis of 34 studies show 20% increased risk, but only 7 of the 34 studies showed significantly increased risk.”

Brenner was apparently referring to the 1993 meta-analysis conducted by the US EPA (Environmental Protection Agency) which was branded a blatant fraud by US District Court Judge, William Osteen, in 1998. The EPA study is among a relative handful of studies which found a (very) small relative risk between SHS and lung cancer/heart disease, but only after manipulating data to conform to their predetermined conclusion.

In fact, as noted often on this blog, the vast majority of studies on the subject find no relationship between lung cancer and SHS. Some (the IARC study conducted on behalf of the WHO) even found a negative association between SHS exposure in kids and lung cancer in later life, suggesting a protective effect from childhood exposure.

Author and epidemiologist, Geoffrey Kabat, claims in his 2008 book, “Hyping Health Risks”, that the danger of passive smoking (secondhand smoke) is a matter of politics and faith - not scientific evidence. "There are few scientists who believe that passive smoking can cause fatal diseases." Huh?

Kabat, together with James Enstrom, published one of the largest studies to date (British Medical Journal, 2002) on the effects of secondhand smoke exposure, finding no correlation between SHS and lung cancer or heart disease. He and Enstrom were subjected to harsh and malicious personal attacks after publishing their study.

"It is basically consistent with what we already know. But the study is interesting because it measures a variety of risks against each other, " Kabat commented on the Canadian study in an interview with Kjellerup. "It confirms the risk relationship between lung cancer and exposure to a variety of hazardous substances and factors in the work environment - and it confirms that passive smoking plays an insignificant role in lung cancer."

Back in June, Denmark’s Minister for Health, Bertel Haarder, was quick to backtrack on a quote attributed to him by Kjellerup, following a hearing on smoking in Copenhagen. “I do not believe that passive smoking is dangerous. I am a non-believer in that theory.”

Haarder, without denying the statement, explained that the quote was taken out of context: “I didn’t know I was being interviewed. We were just standing and chatting – so I don’t think it’s fair that it is being put forward as a ministerial statement.”

“What I am asking, is that journalists tell me when I am being interviewed so that I can be sure that what I say is reported in the right context . . . I had a chat with some people in which I said that passive smoking cannot be as harmful as active smoking and that you cannot put the two on the same footing.” Uh-huh.

Is the Danish Health Minister afraid that expressing a privately held view , “I do not believe that passive smoking is dangerous,” might lead to political retribution? Did he perhaps fear he might be subjected to the kind of personal attacks directed at Kabat and Enstrom?

In a shocking interview with LeParisiene, Dr. Phillipes Even, the former president of the prestigious Necker Research Institute in France, stated unequivocally, “Clearly, the harm [of secondhand smoke] is either nonexistent, or it is extremely low.”

When asked why he didn't speak up earlier, Professor Even explained that his position as a civil servant, dean of the largest medical faculty in France, included an obligation to remain consistent with official policy. “If I had deviated from official positions, I would have had to pay the consequences. Today, I am a free man.”

That the vast majority of studies find no statistical link between secondhand smoke and chronic diseases such as lung cancer and heart disease, is a fact little known to the majority of the population in the US, Canada and other nations where anti-smoker zealots control the agenda.

And, they're unlikely to learn the facts while the anti-smoker booster club in the main stream media chooses to disseminate anti-smoker rhetoric and propaganda unchallenged. They're unlikely to learn the facts when the media ignores conflicting scientific evidence, in effect, refusing to publish dissenting views.

And, they're unlikely to learn the facts when prominent scientists can be intimidated into silence.

Geoffrey Kabat says: "There are few scientists who believe that passive smoking can cause fatal diseases." The latest study from Canada seems to confirm the view that secondhand smoke does not contribute to lung cancer.

But, the public will never know as long as the main stream media continues to present only one side of the argument.

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