Cancer Risk from Exposure to Particulate Matter and Ozone According to Obesity and Health-Related Behaviors: A Nationwide Population-Based Cross-Sectional Study.

BACKGROUND: There is little evidence of an association between cancer risk and long-term exposure to ambient particulate matter <10 μm (PM10 ) and ozone (O3 ), according to obesity and health-related behaviors.

METHODS: In the 2012 Korean Community Health Survey, survey data on socioeconomic characteristics, health-related behaviors, and previous cancer history were collected from 100,867 participants. Daily average concentrations of PM10 and O3 (2003-2012) were obtained from the Korean Air Pollutants Emission Service. The cancer risks for interquartile increases in PM10 and O3 were evaluated using multiple logistic regression and were stratified by age, sex, obesity, and health-related behaviors.

RESULTS: Increased cancer risk was found among obese subjects aged ≥50 years after adjusting for confounding factors [PM10 : ≥60 years: OR 1.34, 95% confidence interval (CI) 1.03-1.74; 50-60 years: OR 1.40, CI 1.01-1.96; O3 : ≥60 years: OR 1.12, CI 1.04-1.20; 50-60 years: OR 1.20, CI 1.08-1.33]. However, we did not observe similar trends in the nonobese subjects. Among obese subjects aged ≥50 who had been exposed to PM10 , men, ever smokers, and inactive subjects were at increased cancer risk. Regarding O3 , the cancer risk was significantly higher among obese adults >50 years old, regardless of sex or health-related behaviors.

CONCLUSIONS: Long-term exposure to PM10 and O3 was found to increase cancer risk. In particular, the risk differed according to obesity status, age, sex, and health-related behaviors.

IMPACT: The effect of air pollution on cancer risk was compounded by obesity, smoking, and physical inactivity among subjects over 50 years old.