Background: A limited number of studies on long-term effects of particulate matter with aerodynamic diameter < 2.5 μm (PM2.5) on health suggest it can be an important cause of morbidity and mortality. In Asia where air quality is poor and deteriorating, local data on long-term effects of PM2.5 to support policy on air quality management are scarce.
Objectives: We assessed long-term effects of PM2.5 on the mortality in a single Asian city.
Methods: For 10–13 years, we followed up a cohort of 66,820 participants ≥ 65 years of age who were enrolled and interviewed in all 18 Elderly Health Centres of the Department of Health, Hong Kong, in 1998–2001. Their residential addresses were geocoded into x– and y-coordinates, and their proxy exposures to PM2.5 at their addresses in 1 × 1 km grids were estimated from the U.S. National Aeronautics and Space Administration (NASA) satellite data. We used Cox regression models to calculate hazard ratios (HRs) of mortality associated with PM2.5.
Results: Mortality HRs per 10-μg/m3 increase in PM2.5 were 1.14 (95% CI: 1.07, 1.22) for all natural causes, 1.22 (95% CI: 1.08, 1.39) for cardiovascular causes, 1.42 (95% CI: 1.16, 1.73) for ischemic heart disease, 1.24 (95% CI: 1.00, 1.53) for cerebrovascular disease, and 1.05 (95% CI: 0.90, 1.22) for respiratory causes.
Conclusions: Our methods in using NASA satellite data provide a readily accessible and affordable approach to estimation of a sufficient range of individual PM2.5 exposures in a single city. This approach can expand the capacity to conduct environmental accountability studies in areas with few measurements of fine particles.
1School of Public Health, The University of Hong Kong, Hong Kong, China; 2School of Health and Population Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom; 3Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom; 4School of Nursing, The Hong Kong Polytechnic University, Hong Kong, China; 5Division of Environment, The Hong Kong University of Science and Technology, Hong Kong, China; 6Department of Health, the Government of Hong Kong, Hong Kong, China
Recommended Citation:
Chit Ming Wong,1 Hak Kan Lai,1 Hilda Tsang,et al. Satellite-Based Estimates of Long-Term Exposure to Fine Particles and Association with Mortality in Elderly Hong Kong Residents[J]. Environmental Health Perspectives,2015-01-01,Volume 123(Issue 11):1167