All-Cause Mortality Risks Associated with Long-Term Exposure to Ambient Fine Particulate Matter in the Chinese Healthy Longevity Cohort

摘要

There is extensive evidence from cohort studies in North America and Europe for increased mortality risk from long-term exposure to fine particulate matter (PM2.5). However, this association has rarely been quantified at higher ambient concentrations. We sought to estimate the hazard ratio (HR) for all-cause mortality from long-term exposures to PM2.5 exposure in a well-defined Chinese cohort of older adults. The Chinese Longitudinal Healthy Longevity Survey (CLHLS) study is a prospective cohort study of elderly men and women enrolled in 2008 and followed through 2014 for mortality events. We studied 13,344 subjects for whom residential locations during the follow-up period were available for linkage to 1 km gridded PM2.5 concentrations, derived from ground-based measurements and satellite remote sensing. The outcome measure was all-cause mortality. Cox proportional hazards models were used to estimate the effect of long-term PM2.5 concentrations on all-cause mortality, controlling for age, sex, smoking status, drinking status, physical activity, BMI, household income, marital status, education. We then applied our results to estimate PM2.5-related premature mortality for persons older than 65 years-of-age in all of China in 2010. The overall HR for a 10 mg/m3 increase in 3-year average PM2.5 concentration was 1.08 (95% CI: 1.06-1.09). There was strong evidence for differences in effects by urban/rural, north/south and high/low PM2.5 exposure. The HR was higher in rural and southern regions, and at lower PM2.5 exposure levels. The estimated total PM2.5 related all-cause mortality of Chinese elderly was 1,765,820 in 2010. Long-term exposure to PM2.5 was associated with an increased risk of all-cause mortality among elderly adults in China, but the magnitude of the risk declined as concentrations increased.