Particulate air pollution on cardiovascular mortality in the tropics: impact on the elderly

• Published in: Environmental health Vol. 18; no. 1; pp. 34 - 9
• Main Authors: Yap, Jonathan, Ng, Yixiang, Yeo, Khung Keong, Sahlén, Anders, Lam, Carolyn Su Ping, Lee, Vernon, Ma, Stefan
• Format: Journal Article
• Language: English
• Published: London BioMed Central 18.04.2019; BioMed Central Ltd; BMC
• Subjects: Adolescent; Adult; Age; Aged; Air Pollutants - analysis; Air pollution; Air Pollution - analysis; Carbon monoxide; Carbon Monoxide - analysis; Cardiovascular disease; Cardiovascular diseases; Cardiovascular Diseases - mortality; Cardiovascular mortality; Child; Child, Preschool; Confidence intervals; Earth and Environmental Science; Elderly; Environment; Environmental aspects; Environmental Health; Epidemiology; Geriatrics; Global Environment; Harvesting; Health aspects; Holidays & special occasions; Humans; Humidity; Infant; Infant, Newborn; Middle Aged; Mortality; Nitrogen dioxide; Nitrogen Dioxide - analysis; Occupational Medicine/Industrial Medicine; Older people; Ozone - analysis; Particulate emissions; Particulate matter; Particulate Matter - analysis; Pollutants; Public Health; Risk factors; Singapore - epidemiology; Studies; Sulfur; Sulfur dioxide; Sulfur Dioxide - analysis; Systematic review; Time series; Trends; Tropical climates; Tropical environment; Tropical environments; Tropics; Variables; Young Adult; Singapore; Air pollution; Elderly; Tropics; Cardiovascular mortality
• ISSN: 1476-069X; 1476-069X
• DOI: 10.1186/s12940-019-0476-4

Background Air pollution has a significant health impact. Most data originate from temperate regions. We aim to study the health impact of air pollution, particularly among the elderly, in a tropical region. Methods A daily time-series analysis was performed to estimate excess risk (ER) of various air pollutants on daily death counts amongst the general population in Singapore from 2001 to 2013. Air pollutants included particulate matters smaller than 10 μm, and 2.5 μm (PM 10 , PM 2.5 ), carbon monoxide (CO), nitrogen dioxide (NO 2 ), ozone (O 3 ) and sulphur dioxide (SO 2 ). The studied outcomes were non-accidental and cardiovascular mortality. Single-day lag and distributed lag models were studied and adjusted for confounders. Results In single-day lag models, a 10 μg/m 3 increase in particulate matter was associated with significant increases in non-accidental (PM 10 ER: 0.627%; 95% confidence interval (CI): 0.260–0.995% and PM 2.5 ER: 0.660%; 95% CI: 0.204–1.118%) and cardiovascular mortality (PM 10 ER: 0.897; 95% CI: 0.283–1.516 and PM 2.5 ER: 0.883%; 95% CI: 0.121–1.621%). This was significant in the elderly ≥ 65 years but not in those < 65 years and were seen in the acute phase of lag 0-5 days. Effects by other pollutants were minimal. For cardiovascular mortality, the effects turned protective at a cumulative lag of 30 days in the elderly and could due to “harvesting”. Conclusions These first contemporary population-based data from an equatorial country with tropical climate show that exposure to particulate air pollution was significantly associated with non-accidental mortality and cardiovascular mortality, especially in the elderly.