摘要：

Bialous and Yach have recently published an article in Tobacco Control in which they claim that all smoking-machine standards stem from a method developed unilaterally by the tobacco industry within the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA). Using a few highly selective quotations from internal tobacco company memos, they allege, inter alia, that the tobacco industry has changed the method to suit its own needs, that because humans do not smoke like machines the standards are of little value, and that the tobacco industry has unjustifiably made health claims about low "tar" cigarettes. The objectives of this paper are to review the development of smoking-machine methodology and standards, involvement of relative parties, outline the significance of the results and explore the validity of Bialous and Yach's claims. The large volume of published scientific information on the subject together with other information in the public domain has been consulted. When this information is taken into account it becomes obvious that the very narrow and restricted literature base of Bialous and Yach's analysis has resulted in them, perhaps inadvertedly, making factual errors, drawing wrong conclusions and writing inaccurate statements on many aspects of the subject. The first smoking-machine standard was specified by the Federal Trade Commission (FTC), a federal government agency in the USA, in 1966. The CORESTA Recommended Method, similar in many aspects to that of the FTC, was developed in the late 1960s and published in 1969. Small differences in the butt lengths, smoke collection and analytical procedures in methods used in various countries including Germany, Canada and the UK, developed later, resulted in about a 10% difference in smoke "tar" yields. These differences in methodology were harmonised in a common International Organisation for Standardisation (ISO) Standard Method in 1991, after a considerable amount of interlaboratory comparisons of the developing methodology had been undertaken by CORESTA. As acknowledged by Bialous and Yach, the purpose of the standards is to determine the "tar", nicotine and carbon monoxide content of cigarette smoke when the cigarette is smoked under precisely defined conditions, and hence to allow a comparison of the yields from different cigarettes when smoked under identical conditions. Such yields are not predictive of the yields humans obtain when smoking, nor were they ever expected to be so, since no two smokers smoke exactly the same nor does a smoker smoke a cigarette the same way on every occasion. This purpose has been stated consistently many times, originally by the FTC in 1967 and subsequently in the scientific literature, published by the tobacco industry and health/regulatory authorities, over the last 35 years. From the 1950s onwards numerous public health scientists have advocated that lower "tar" cigarettes should be developed on the grounds that they may reduce to some extent the risks of smoking, while at the same time advocating that the best way to avoid risks is not to smoke. Some health authorities have have used the standard machine-smoking yields to set limits on "tar" as a way of reducing the health impact of cigarette use. The tobacco industry has co-operated with these health authorities by developing cigarettes with lower "tar" but has also followed public health advice by not advertising lower "tar" cigarettes as safe cigarettes. The available evidence, taken as a whole, indicates that compensation by smokers who switch from a high to a low "tar" cigarette is partial in the short term, and that such smokers do obtain a reduction in smoke component uptake.

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