Association of Particulate Air Pollution With Daily Mortality: The China Air Pollution and Health Effects Study

TLDR

China has some of the world’s highest particulate matter levels, yet few health studies have been conducted there. The study aimed to assess the association between fine particulate matter (PM10) and daily mortality across 16 Chinese cities from 1996 to 2008. Researchers used two‑stage Bayesian hierarchical models and Poisson regression with natural spline smoothing to estimate city‑specific and national effects while adjusting for long‑term and seasonal mortality trends and other covariates. PM10 concentrations ranged 52–156 µg/m³, and a 10‑µg/m³ increase in the 2‑day moving average was linked to 0.35 % higher total mortality, 0.44 % higher cardiovascular mortality, and 0.56 % higher respiratory mortality, with women, the elderly, and low‑educated residents most vulnerable, indicating short‑term exposure raises mortality risk.

Abstract

China is one of the few countries with some of the highest particulate matter levels in the world. However, only a small number of particulate matter health studies have been conducted in China. The study objective was to examine the association of particulate matter with an aerodynamic diameter of less than 10 μm (PM(10)) with daily mortality in 16 Chinese cities between 1996 and 2008. Two-stage Bayesian hierarchical models were applied to obtain city-specific and national average estimates. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trends of mortality, as well as other time-varying covariates. The averaged daily concentrations of PM(10) in the 16 Chinese cities ranged from 52 μg/m(3) to 156 μg/m(3). The 16-city combined analysis showed significant associations of PM(10) with mortality: A 10-μg/m(3) increase in 2-day moving-average PM(10) was associated with a 0.35% (95% posterior interval (PI): 0.18, 0.52) increase of total mortality, 0.44% (95% PI: 0.23, 0.64) increase of cardiovascular mortality, and 0.56% (95% PI: 0.31, 0.81) increase of respiratory mortality. Females, older people, and residents with low educational attainment appeared to be more vulnerable to PM(10) exposure. Conclusively, this largest epidemiologic study of particulate air pollution in China suggests that short-term exposure to PM(10) is associated with increased mortality risk.