Satellite-based estimates of long-term exposure to fine particles and association with mortality in elderly Hong Kong residents

Chit Ming Wong, Hak Kan Lai, Hilda Tsang, Thuan Quoc Thach, G. Neil Thomas, Kin Bong Hubert Lam, King Pan Chan, Lin Yang, Alexis K.H. Lau, Jon G. Ayres, Siu Yin Lee, Wai Man Chan, Anthony J. Hedley, Tai Hing Lam

Research output: Journal article publicationJournal articleAcademic researchpeer-review

140 Citations (Scopus)


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 PM2.5to support policy on air quality management are scarce. Objectives: We assessed long-term effects of PM2.5on 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 PM2.5at 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/m3increase in PM2.5were 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 cerebro vascular 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 PM2.5exposures in a single city. This approach can expand the capacity to conduct environmental accountability studies in areas with few measurements of fine particles.
Original languageEnglish
Pages (from-to)1167-1172
Number of pages6
JournalEnvironmental Health Perspectives
Issue number11
Publication statusPublished - 1 Nov 2015

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


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