Even 3 Cigarettes a Day Carry an Increased Risk of Heart Disease

The America Cancer Society, as part of the Cancer Prevention Study II that started in 1982, examined the risks of cardiovascular disease at different levels of fine particulate matter from active and passive cigarette smoke, as well as from air pollution. A report is in the journal Circulation.    

Data from more than a million adults included not only changes in fine particulate matter, but also information on education, marital status, body mass index (BMI), alcohol use, occupational exposures, and diet. Cardiovascular mortality of the participants was recorded.

Cardiovascular mortality was substantially increased at very low levels of active cigarette smoking, and slightly but significantly increased at lower particulate matter exposure levels associated with second-hand smoke and ambient air pollution. Putting the findings in perspective, the investigators report that the risk of cardiovascular disease increased by 64% by smoking 3 cigarettes a day, and was doubled by smoking a pack (20 cigarettes) a day.

Further, the findings show that at relatively low levels of particulate matter exposure, the dose-effect relationship is steep, but it levels off at higher concentrations; most studies of this nature are done in areas where the annual average particulate matter concentration is less than 30 micrograms/cubic meter, whereas pollution in urban areas of China or India often exceed 100 micrograms/cubic meter. The difference in risk between, say, 5 and 20 micrograms/cubic meter is considerable, whereas that between 50 and 200 is relatively small. That’s why it’s important to give up smoking only 3 cigarettes a day!