Effect of ambient air pollution on daily mortality rates in Guangzhou, China

We aimed to investigate the effects of ambient air pollutants on daily mortality in a relatively stable and homogeneous population in Guangzhou, China. Daily mortality, air pollution, and weather data between 2006 and 2009 were collected. The generalized additive model with poison regression was used to estimate the excessive risks (ERs) of air pollutants (PM10, SO2, and NO2) on total, cardiovascular and respiratory mortality. The effects of lag0–1 were the greatest for total non-accidental and cardiovascular deaths. The increments of 10 μg m−3 in SO2, NO2, and PM10 were associated with ERs of 1.54% (95%CI: 1.03–2.06%), 1.42% (95%CI: 1.06–1.78%), and 1.26% (95%CI: 0.86–1.66%) respectively for total non-accidental deaths, and 2.28% (95%CI: 1.40–3.16%), 1.81% (95%CI: 1.20–2.41%), and 1.79% (95%CI: 1.11–2.47%) respectively for cardiovascular deaths. For persons who died from respiratory disease, however, the maximum effects occurred at lag0. The ERs for SO2, NO2, and PM10 were 1.36% (95%CI: 0.23–2.50%), 1.47% (95%CI: 0.66–2.29%) and 0.93% (95%CI: 0.03–1.83%), respectively. The effects of the three air pollutants on mortality were stronger in elderly and in women. The ERs in the present study were higher than those reported in Europe, the U.S., and most other Asian cities. Our findings show relatively higher ERs of daily mortality by ambient air pollutants in the center of Guangzhou, China, compared with estimates in other cities. Further studies with accurate exposure measurement among homogeneous population are needed to evaluate the precise magnitudes of the effects of the air pollutants.