Scientific evidence on passive smoking is inconclusive

Jan 17 2005

Scientific evidence on environmental tobacco smoke (ETS or so-called "passive smoking") is inconclusive and does not justify a total ban on smoking in public places, it was argued at a conference on public smoking in Edinburgh today.

A more scientifically justifiable approach would be to focus on improving general air quality through better ventilation, combined with greater choice of non-smoking and smoking facilities, delegates were told.

Today's conference was organised by the Scottish Licensed Trade ' Association (SLTA) to debate the issues raised by the Scottish Executive's proposed new law prohibiting smoking in all enclosed public places.

Dr. Steven Stotesbury, a scientist from Imperial Tobacco, presented an analysis of studies, most of them carried out in America or Asia, that have looked at the association between exposure to ETS and increased risk of serious diseases, such as lung cancer and heart disease, among non-smokers. Few of the studies were large enough to give any clear indication of increased risk and the largest studies produced inconsistent results. Stotesbury said: "Any objective assessment of the evidence must conclude that if there is an increased risk of chronic diseases, such as lung cancer and heart disease, from exposure to ETS, it is small and hard to measure with any certainty."

He went on: "However, when it comes to ETS, the evidence is not assessed objectively or by the same criteria as are applied to other potential sources of risk to health. Levels of relative risk, which have been officially described as too low to prove a causal effect(1), are used to substantiate the opposite in the case of ETS and therefore to justify extreme public smoking measures. Even more misleadingly, risk estimates that are based on a mathematical combination of different studies, many of which are weak or inconclusive, are extrapolated into headline claims about specific numbers of deaths 'due to passive smoking'. In other words, the science and the statistics have been exaggerated to fit the anti-smoking case".

Tim Lord, chief executive of the Tobacco Manufacturers' Association (TMA) commented: "We know from many sources, including the Scottish Executive's own public opinion research, that the public wants more restrictions on public smoking but would prefer greater choice of non-smoking and smoking facilities to an outright ban. The TMA fully supports this approach and believes the scientific evidence does not justify the total ban proposed by the Scottish Executive."

http://www.the-tma.org.uk/