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Posts : 512 Join date : 2010-10-14
| Subject: Epidemiological studies Tue Oct 19, 2010 3:06 am | |
| Epidemiological studies show that non-smokers exposed to secondhand smoke are at risk for many of the health problems associated with direct smoking. In 1992, the Journal of the American Medical Association published a review of available evidence on the relationship between secondhand smoke and heart disease, and estimated that passive smoking was responsible for 35,000 to 40,000 deaths per year in the United States in the early 1980s.[60] The absolute risk increase of heart disease due to ETS was 2.2%, while the attributable risk percent was 23%. Research using more exact measures of secondhand smoke exposure suggests that risks to nonsmokers may be even greater than this estimate. A British study reported that exposure to secondhand smoke increases the risk of heart disease among non-smokers by as much as 60%, similar to light smoking.[61] Evidence also shows that inhaled sidestream smoke, the main component of secondhand smoke, is about four times more toxic than mainstream smoke, a fact that known to the tobacco industry since the 1980s, which kept its findings secret.[62] [63] [64] [65] Some scientists believe that the risk of passive smoking, in particular the risk of developing coronary heart diseases, may have been substantially underestimated.[66] A minority of epidemiologists find it hard to understand how environmental tobacco smoke, which is far more dilute than actively inhaled smoke, could have an effect that is such a large fraction of the added risk of coronary heart disease among active smokers.[67][68] One proposed explanation is that secondhand smoke is not simply a diluted version of "mainstream" smoke, but has a different composition with more toxic substances per gram of total particulate matter.[67] Passive smoking appears to be capable of precipitating the acute manifestations of cardio-vascular diseases (atherothrombosis) and may also have a negative impact on the outcome of patients who suffer acute coronary syndromes.[69] increase website trafficweb design london | |
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