A question of standards for tobacco
Thursday, April 29th, 2010In a paper just published in the Lancet, with the provocative title “Secret science: tobacco industry research on smoking behaviour and cigarette toxicity”, David Hammond, of *Waterloo University in Canada and Neil Collishaw and Cynthia Callard, two members of Physicians for a Smoke-Free Canada, a lobby group, criticise the behaviour of British American Tobacco (BAT). They say the firm considered manipulating some of its products in order to make them low-tar in the eyes of officialdom while they actually delivered high tar and nicotine levels to smokers.
It was and is no secret, as BAT points out, that people smoke low-tar cigarettes differently from high-tar ones. The reason is that they want a decent dose of the nicotine which tobacco smoke contains. They therefore pull a larger volume of air through the cigarette when they draw on a low-tar rather than a high-tar variety. The extra volume makes up for the lower concentration of the drug.
But a burning cigarette is a complex thing, and that extra volume has some unexpected consequences. In particular, a bigger draw is generally a faster draw. (3)That pulls a higher proportion of the air inhaled through the burning tobacco, rather than through the paper sides of the cigarette. This, in turn, means more smoke per unit volume, and thus more tar and nicotine. The nature of the nicotine may change, too, with more of it being in a form that is easy for the body to absorb.
Regardless of how this came about, the irony is that low-tar brands may have ended up causing more health problems than high-tar ones.[/color][/b] As one of BAT’s medical consultants put it as early as 1978, “Perhaps the most important determinant of the risk to health or to a particular aspect of health is the extent to which smoke is inhaled by smokers. If so, then deeply inhaled smoke from low-tar-delivery cigarettes might be more harmful than uninhaled smoke from high-tar cigarettes.” The firm, meanwhile, points out that the ISO test has been regarded as unreliable since 1967, and says its scientists have been part of a panel that is working on a new ISO standard.