Two seminars will be presented by two speakers. "Chemical change in secondhand tobacco smoke...." (by Dr. Schick): The major US tobacco companies responded to Hirayama et al's 1981 paper showing secondhand smoke can cause lung cancer in nonsmokers by intensifying their study of the chemistry and toxicity of secondhand smoke. Using a variety of experimental approaches, RJ Reynolds and Philip Morris studied the effects of aging, dilution and contact with typical room surfaces on secondhand smoke chemistry. Most studies showed a net loss of chemical compounds with time and many of these studies were published. However, the internal tobacco industry documents also contain unpublished data indicating that, under some environmental conditions, aldehydes increase in concentration over time. In vivo smoke exposure experiments with aged sidestream smokes suggest that while aging decreases the concentration of smoke components, the toxicity of aged smoke, per unit mass, is equal to or greater than that of fresh sidestream smoke. "Tobacco companies successfully prevented tobacco control legislation in Argentina" (by Dr. Sebrie): A study of successful efforts by the tobacco companies to prevent tobacco control legislation in Argentina over the past 40 years will be briefly summarized. Information from internal tobacco industry documents sheds light on strategies similar to those applied in the US and other countries.