s Air Pollution and Lung Cancer

The health effects of air pollution have been subject to intense study in recent years. These effects have been found in short-term studies, which relate day-to-day variations in air pollution and health, and long-term studies, which have followed cohorts of exposed individuals over time. Epidemiological evidence has concurred with clinical and experimental evidence to correlate current levels of ambient air pollution, both indoors and outdoors, with respiratory effects. The association between ambient air pollution exposure and lung cancer risk indicates that long-term exposure to air pollution may cause lung cancer. In the 1950s evidence of an ongoing epidemic of lung cancer in the United States and Europe led researchers to examine the role of outdoor air pollution, which was considered by some to be a likely cause. This concern is based on the fact that known carcinogens continue to be released into outdoor air from industrial sources, power plants, and motor vehicles. The present article reviews the epidemiologic evidence for this association and discusses the limitations of current studies for estimating the lung cancer risk in the general population. It also identifies research needs and suggests possible approaches to addressing outstanding questions like the causality assessment, which can benefit from biomarker research.