Preventive medicine
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Preventive medicine · Mar 1985
Characterization of tobacco products: a comparative study of the tar, nicotine, and carbon monoxide yields of cigars, manufactured cigarettes, and cigarettes made from fine-cut tobacco.
Yields of tar, nicotine, and carbon monoxide were compared in selected Canadian brands of manufactured and hand-rolled cigarettes, and small and large cigars. To control for varying volumes of smoke delivery per cigarette or cigar, standardized comparisons in milligrams of toxic substance per liter of smoke were made. The mean deliveries per liter of smoke and tar, nicotine, and carbon monoxide were highest for small cigars, followed by hand-rolled and manufactured cigarettes; large cigars had the lowest deliveries. Five out of six brands of cigarettes handmade from fine-cut tobacco delivered significantly more tar, nicotine, and carbon monoxide per cigarette or per liter than did the identically named manufactured brand.
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Preventive medicine · Nov 1984
ReviewLung dynamics and uptake of smoke constituents by nonsmokers--a survey.
Models of smoke kinetics and lung dynamics of inhaled particles are discussed and compared with the available literature on mainstream and sidestream smoke particles. The literature search reveals a dearth of reliable information on the deposition of inhaled particulate tobacco smoke components in the human lung. Scanty results on mainstream smoke range from unexpectedly high deposits to values in line with predictions of conventional mathematical deposition models confirmed in tests with stable aerosols. ⋯ It is in agreement with established deposition probabilities. Experimental and theoretical estimates of relative particle deposition in the human lung range from some 10% for sidestream smoke particles to more than 80% for mainstream aerosol. This indicates a need for more, and better, experimental data.
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The acute irritating and annoying effects of smoke have been investigated in field and laboratory studies by examining the concentration of some smoke components in air. In the workplace, 30 to 70% of the indoor carbon monoxide, nitrogen oxide, and particulate concentrations are due to tobacco smoke; 25-40% of the employees are disturbed and/or annoyed by smoke and 25% suffer from eye irritation at work. Subjective eye, nose, and throat irritations and eye blink rate increase with increasing smoke concentration and increasing exposure duration. ⋯ Above these limits, countermeasures to protect passive smokers are necessary. In order not to exceed the upper tolerable threshold limit of 2.0 ppm carbon monoxide, it is necessary to have a fresh air supply of 33 m3 per hour per cigarette smoked. Special attention should be paid to groups of people with increased sensitivity to environmental tobacco smoke, e.g., asthmatics, allergic individuals, chronic bronchitis sufferers, and children.
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Preventive medicine · Sep 1984
Comparative StudyMaintain levels of nicotine but reduce other smoke constituents: a formula for "less-hazardous" cigarettes?
Twenty-two volunteers who smoked more than 20 cigarettes with "high" nicotine yields (0.8 to 1.2 mg) per day participated in an 8-week study designed to test the hypothesis that smoking cigarettes with a constant level of nicotine but reduced deliveries of tar, carbon monoxide, and hydrogen cyanide leads to a decrease in smoke absorption. All subjects smoked their usual high-nicotine brand for the first 3 weeks (P1), and the absorption of smoke constituents was determined from levels of thiocyanate and cotinine in saliva and serum, levels of carbon monoxide in expired air, and levels of carboxyhemoglobin in the blood. During the final 5 weeks (P2), the treatment group (16 subjects) switched to the "light" version of their usual brands (similar yields of nicotine but with reduced yields of tar, carbon monoxide, and hydrogen cyanide); the control group (6 subjects) smoked their usual brands for the duration of the study. ⋯ Slight reductions were noted in average expired-air carbon monoxide levels, blood carboxyhemoglobin, and saliva thiocyanate, but these reductions were smaller than anticipated based on brand characteristics. The results suggest that the ratio of smoke constituents is different when individuals, rather than machines, smoke cigarettes. Yields determined under subject-defined conditions are necessary in order to properly evaluate the role of nicotine in the design of "less-hazardous" cigarettes.
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Preventive medicine · Jul 1984
Prognostic importance of cholesterol levels after myocardial infarction.
The aim of this study was to analyze the relationship between serum cholesterol level and all causes mortality in men who sustained a first myocardial infarction. The cholesterol distribution 3 months after the infarction was established. Ten annual cohorts (n = 1,204) were followed for a maximum period of 11 years. ⋯ When all ages were analyzed together, the total mortality was higher in the upper cholesterol quintiles (P = 0.02). This association was confirmed when analyzed with Coxian adjustments for age, change in smoking habits after infarction, and the previously mentioned prognostic function. When broken down by age (less than or equal to 49, 50-59, greater than or equal to 60) and period of follow-up (3-24 and 25-84 months), the association between mortality and cholesterol quintiles was confined to patients under 50 years during the late follow-up period (P = 0.01), whereas there was no association for the other age groups.