2016 Volume 51 Issue 6 Pages 245-256
A systematic review was conducted to evaluate the effects of long-term exposure to particulate matter with diameters of less than 2.5 μm (PM2.5) on mortality. We searched PubMed for epidemiological studies investigating the association of long-term exposure to PM2.5 with mortality published between January 1990 and December 2015. We applied a random-effects model to calculate the combined effect estimates for PM2.5 mass. Twenty-four articles were identified (3 from Asia, 6 from Europe, and 15 from North America). It was common to assign the PM2.5 observations monitored at a fixed-site station to all residents in the corresponding area in the study published during 1990–2000. Recently, PM2.5 exposure assessment has utilized dispersion models, land use regression models, and satellite remote sensing. The mean or median concentration of PM2.5 for each study area varied from 8.1 to 35.3 μg/m3. The combined risk ratio was 1.07 (95% confidence interval: 1.04, 1.19) per 10 μg/m3 increase in the PM2.5 concentration. There was a significant heterogeneity. Further studies are needed in the area where the PM2.5 level is high.
