Cumulative exposure to air pollution and subsequent mortality among older adults in China

Background Research on the health effects of exposure to air pollution is growing. However, relatively little attention has been paid to the effects of long-term and cumulative exposure to air pollutants. Individual-level studies on the health consequences of air pollution in China are especially scarce. The purpose of this study is to examine the effect of cumulative exposure to sulfur dioxide (SO2), an air pollutant of particular concern in China, on all-cause mortality in older Chinese adults. Methods Using a nationally representative sample of older adults in China (N = 11 199), we tracked mortality over an 11-year period (2000-11). Air pollution data were linked to respondents using provincial identifiers. To examine the effect of cumulative SO2 exposure on mortality, we employed multilevel multinomial logistic regression models that account for within subject clustering of observations over time and clustering at the province level. Results We found that every 10-mu g/m(3) increase in cumulative exposure to SO2 increased the odds of death by nearly 1% (OR = 1.008; 95% CI: 1.002-1.014), controlling for province- and individual-level social and economic characteristics. Conclusions Our analysis shows that air pollution is a risk factor for morality in older Chinese adults. Findings suggest that stronger SO2 regulations may enhance longevity.