Indoor Air Pollution and Cardiovascular Disease

Serious attention was first focused on indoor air pollution as a public health problem in the 1960s, when some of the first measurements of indoor pollutant concentrations, including nitrogen dioxide, carbon monoxide, and particles, were made.1 Studies combining the tracking of activity patterns with monitoring of indoor and outdoor concentrations for key air pollutants soon led to an appreciation of the dominant contributions of indoor exposures to total personal exposures (ie, the total exposure experienced by an individual across the multiple environments where time is spent).2 A wave of epidemiological studies was also launched, directed at secondhand tobacco smoke, nitrogen dioxide from natural gas–fueled stoves and heaters, and other pollutants with indoor sources. These studies focused on the pollution sources present in higher-income countries, particularly in North America and Europe, and their adverse effects on health, particularly the respiratory health of children and adults. Collectively, the resulting evidence has given us an understanding of the critical role of indoor environments in driving exposures to inhaled pollutants and provided sufficient evidence to causally link secondhand tobacco smoke exposure to increased disease risk, including coronary heart disease and stroke, and other adverse effects in infants, children, and adults.3Article, see p 2360By the 1980s, the problem of indoor exposure to smoke from the burning of biomass fuels for cooking and heating was first recognized. Smith et al4 reported pioneering observations from India, measuring remarkably high personal exposures to particulate matter for women as they cooked over an open fire. The repeated documentation of such high exposures to biomass fuel smoke, generally with particulate matter used as the indicator of combustion pollution, motivated epidemiological studies of the consequences. The resulting body of evidence is substantial and supports the inference of a causal association of smoke from biomass fuels …