Preventive medicine
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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.
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Preventive medicine · Mar 1984
Comparative StudyHemodynamic effects of oral smokeless tobacco in dogs and young adults.
Oral smokeless tobacco (snuff) is increasingly used among the young male population. To determine cardiovascular effects of an oral smokeless tobacco product, 10 anesthetized dogs were instrumented to measure blood pressure, heart rate, left ventricular end diastolic pressure, and circumflex coronary, renal, and femoral flows. After a 5-min baseline, a 2.5-g, approximately 1.2% nicotine bolus dose was placed in the buccal space, and measurements were made for 20 min. ⋯ Additionally, 20 human males, mean age 20 years, without nicotine exposure for 72 hr, were given a 2.5-g dose of the same oral smokeless product. From baseline to 20 min, heart rate increased from 69 to 88 beats/min (P less than 0.05), blood pressure from 118/72 to 126/78 mm Hg (P less than 0.05). Thus, oral smokeless tobacco use can produce significant hemodynamic changes in both dogs and normal humans.
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Preventive medicine · Sep 1983
Comparative StudyA comparison of the yields of tar, nicotine, and carbon monoxide of 36 brands of Canadian cigarettes tested under three conditions.
A number of countries, including Canada, sponsor routine monitoring of cigarette tar, nicotine, and carbon monoxide yields which are evaluated by cigarette-smoking machines according to a standard protocol. These standardized yields continue to decline as tobacco companies modify their brands to meet consumers' demand for "light" products. ⋯ Thirty-six brands of Canadian cigarettes, including 28 with ventilated filters, were tested under standard conditions and 2 others in order to determine how yields of tar, nicotine, and carbon monoxide change when cigarettes are manipulated by smokers in order to increase their smoke intake. While the rank order yields of tar, nicotine, and carbon monoxide was preserved, the average yields of all three substances more than doubled when cigarettes were intensively smoked in comparison with standard smoking.