Study On Air Pollution And Population Health In Beijing

Objective:We conducted a time-series analysis, which applied the principal component analysis to adjust collinearity of multi-pollutants, to evaluate associations between daily mortality and the major air pollutants in Beijing after the 2008 Beijing Olympics.Methods:For both city-wide and district-specific association analysis, the generalized additive models (GAM) with natural splines was used to associate air pollutants with daily nonaccidental and cause-specific mortality, covariates and confounders. Specifically, we used the principal component analysis to avoid collinearity of multi-pollutants.Results:On the city-wide level, in single air pollutant model with two-day moving average concentrations of the air pollutants, increase in their interquartile range (IQR) associated with percent increase in nonaccidental mortality,2.55 percent [95% confidence interval (CI):1.99,3.11] for CO,2.54 percent (95% CI:2.00,3.08) for NO2 and 1.80 percent (95% CI:1.21,2.40) for PM10, respectively. The effects decreased but remained significant after adjusting collinearity by principal component analysis:0.97 percent (95% CI:0.77,1.17) for CO,1.04 percent (95% CI:0.82,1.25) for NO2 and 1.07 percent (95% CI:0.85,1.30) for PM10, respectively. The trend was also observed in cardiovascular mortality and respiratory mortality. On the district-specific level, the respiratory effects were varied across the districts. The strongest effects were found in three rural districts (Daxing, Pinggu, Miyun) but significant only in Daxing district.Conclusions:After adjusting collinearity of multi-pollutants, air pollution remained a significant contributor to nonaccidental and cardiopulmonary mortalities in Beijing during 2009-2010. The high risk found in rural areas suggests a potential susceptible sub-population with undiagnosed respiratory diseases in these areas. Although the rural areas have relative lower air pollution levels, they deserve more attention to respiratory disease prevention and air pollution reduction.