Throughout most of the 1960s, the tobacco industry was convinced that it could make cigarettes safe—that is, that it could discover the toxic components of cigarette smoke and eliminate them. In the lab the tobacco industry's scientists quietly worked on reducing the toxicity of cigarettes by various means. To this end, they developed an array of biological tests, using mouse skin painting (cigarette tar painted on the skins of mice) as the gold standard for testing carcinogenicity. At the same time, in its public statements the industry challenged the validity of this test as evidence that tobacco poses any harm to human consumers. In fact, we now know that mouse skin painting underestimates the total carcinogenic action of tobacco smoke. Some of the most important carcinogens in tobacco, such as nitrosamines, are in the gas phase of the smoke, not in the particulate phase that makes up the "tar" painted on the skins of mice (1). As with its research on nicotine, the secret research being conducted by the tobacco industry was at least as high in quality as the work reported in the open scientific literature at the time. Despite the importance and quality of this research, little of it was ever published in peer-reviewed scientific journals.
B&W and BAT's early work seemed motivated by a genuine concern over the health effects of smoking and a belief that, if the toxic components of cigarette smoke could be identified, these agents could be removed and a "safe" conventional cigarette created. By the late
1970s, however, the tobacco industry had largely abandoned the search and turned to a more defensive posture. This chapter describes what the documents reveal about the industry's effort to develop a "safe" cigarette. The industry did not disclose these research efforts to the public, and it was simultaneously engaged in two campaigns: an internal research campaign to develop a "safe" cigarette and an external public relations campaign to convince the public that cigarettes had not been proven dangerous to health.
As discussed in chapter 2, in the 1950s, in the wake of the rapidly growing scientific evidence that cigarettes cause lung cancer (2), cigarette companies created brands with filters and claimed that these brands gave "health protection" to smokers. These claims were not based on proof of "health protection"; indeed, some filter brands had higher tar deliveries than unfiltered products from the same manufacturer, and smoke from filter cigarettes was shown to be just as carcinogenic as smoke from unfiltered brands (3). Nonetheless, the hype worked, and by 1960 filter brands were well on their way to replacing nonfilter cigarettes in the marketplace. At the same time, cigarette companies conducted serious research to see whether they could lower the toxicity of their products.