Study: Passive smoke does no harm
Professional anti-smoking lobby groups are fuming over the publication of a longitudinal study -- in a prestigious medical journal -- showing that passive smoke is harmless.
The study has been heading toward publication for years, generating considerable background noise along the way, but its release in the prestigious British Medical Journal (BMJ) on 17 May has lit a fire under anti-smoking groups.
"Environmental tobacco smoke and tobacco related mortality in a prospective study of Californians, 1960-98" doesn't make for easy reading -- but its conclusions are abundantly clear: second hand smoke does not cause heart disease or cancer, and has only a barely appreciable affect on chronic obstructive pulmonary disease.
This is shocking news for the enormous grants-dependent industry built around claims that passive smoke increases the risk of heart disease by 23-30 per cent and lung cancer by 20 per cent -- and anti-smoking groups were predictably quick to fire up word processors in an onslaught of attacks on the study, its funding, and the journal that published the study.
Funding as a source of science
First off the mark, anti-smoking pressure group Ash derided the study, saying it had been funded by the tobacco industry.
Amanda Sandford of Ash was quoted in The Independent as saying: "This paper is just the latest in a long campaign to sow the seeds of doubt about the dangers of breathing in environmental tobacco smoke. The authors appear to be deliberately downplaying the findings to suit their tobacco industry paymasters."
If the tobacco industry was the "paymaster" of the researchers, however, it was only briefly, recently, and after the likely results of the study became apparent to the anti-smoking groups that had funded it for nearly 40 years.
The study was originally undertaken in 1959 by the American Cancer Society, which backed away from the study for unspecified reasons in 1972, but continued to maintain the database. Funding was then supplied through 1997 through the Tobacco-Related Disease Research Program, an anti-smoking University of California research organisation funded by a state-levied cigarette surtax.
In their paper, the authors of the study say: "After continuing support from the Tobacco-Related Disease Research Program was denied, follow up through 1999 and data analysis were conducted at University of California at Los Angeles with support from the Center for Indoor Air Research, a 1988-99 research organisation that received funding primarily from US tobacco companies."
Author James E Enstrom says he has recently received some funding from the tobacco industry for "tobacco related epidemiological research because it has been impossible ... to obtain equivalent funds from other sources." Author Geoffrey C Kabat says he had never received tobacco industry funding until last year, when he "conducted an epidemiological review for a law firm which has several tobacco companies as clients." Both researchers are "lifelong non-smokers whose primary interest is an accurate determination of the health effects of tobacco," they say.
But even a drop of "special interest" backing is sufficient to poison the fruit on the research tree, according to some -- and the anti-smoking lobby is not above using distortion to make that point.
In Australia, National Heart Foundation tobacco spokesman Maurice Swanson, for example, told News.com.au that the study was suspect because the researchers had failed to secure their funding "through the normal review process" and that it "was subsequently funded by the tobacco industry." a complete misrepresentation of the actual funding history of the research.
Public policy versus science
Some in the anti-smoking lobby said the paper should not have been published at all, given the tobacco industry backing it received in its final phase.
Others, like Australia's Cancer Council Australia chief executive Alan Coates attacked the science of the study directly, but erroneously.
Mr Coates, for example, claimed that the study had not taken into account the degree to which non-smokers were exposed to environmental smoke by their smoking spouses, when it had -- and had found, in fact, that the degree of exposure had no effect on outcomes.
Still others raised the long history of studies that have found harmful effects as a blanket defence against the findings in the new study. The authors of the paper, however, noted in the abstract that the large set of findings indicating harm from environmental smoke was based " primarily on meta-analysis" and is "still controversial due to methodological problems."
The authors write that: "Most epidemiological studies have found that environmental tobacco smoke has a positive but not statistically significant relation to coronary heart disease and lung cancer. Meta-analyses have combined these inconclusive results to produce statistically significant summary relative risks."
Among the most important problems in studies finding harmful effects is the presence of what are known as "confounding factors", behaviours or other factors that could have an unrecognised effect on outcomes.
One controversial study done in New Zealand, for example, includes former smokers in the victim mix and uses second hand, unverified data. The new study, on the other hand, limits the effects of passive smoking to a large body of first hand evidence from participants who had never smoked.
Where you stand is where you publish
It has long been a contention of the anti-smoking establishment that funding influences outcomes in studies of the effects of environmental smoke, and that studies finding no harm or slight harm have been influenced by the tobacco industry. A 1998 study of the literature published in JAMA, for example, contended that while 36 per cent of articles in medical journals concluded that passive smoking was not harmful to health, all of those articles were subsidised in whole or part by the tobacco industry. The study stated that "the only factor associated with concluding that passive smoking is not harmful was whether an author was affiliated with the tobacco industry," and warned readers to note funding histories when evaluating results.
Just so, says the tobacco industry, which claims that the anti-smoking cartel has overwhelming influence on major publications and grant-making agencies, making it difficult for objective science to prosper.
The appearance of this study in a journal as prestigious as the BMJ has at least as much significance for that debate as it does for the legitimacy of the anti-passive smoke agenda.
As The Guardian points out, BMJ editor Richard Smith has unassailable anti-tobacco credentials and quit a professorship after Newcastle University accepted Â£3.8m of funding from British American Tobacco.
While the study may be picked at in details, its placement in the BMJ means it cannot be ignored by public policy makers.
Professor Martin Jarvis, an expert on smoking research at the University of London, defended the BMJ's decision to publish the paper in a comment quoted by The Independent: "Historically, there have been many instances of research funded by the tobacco industry which were not worth the paper they were written on. But that does not mean this paper is not worth looking at. Science is science, and one must not take the view that anything which has got any association with the industry is wrong," he said.
Lead author Enstrom, meanwhile, isn't saying the study should stand as the definitive refutation of all that has gone before, but only that scientists and policy makers who have been relying on one-sided data for two decades should include the study results in their meta-analysis summaries.
Mr Enstrom told the Straits Times: "There should at least be a re-examination of some of the previous summaries of the data to incorporate these findings."
But, as The Telegraph -- which has a history of challenging what it calls the "dubious science" behind claims that passive smoke kills -- points out, villification, not edification, is likely to be the primary outcome of publication, at least initially.
Prof Enstrom told The Telegraph: "One journal we tried had published three positive studies before, but despite getting a glowing referee's report on our work, they refused to accept it."
After the BMJ published it last week, he has been subjected to a barrage of criticism: "The whole process has been aggressive, vitriolic hate," he says.
So much for science.
But then, as Prof Enstrom told The Telegraph: "But maybe we've gone past the point where anyone cares about the facts."