Discussion
C0
is a sensitive parameter in estimating the health effect
of pollutants, when the threshold concentration chosen
relatively high, the economic costs of adverse health effects of PM10 pollution is low, when the selected
threshold concentration is relatively low, the high economics cost of adverse health effects of PM10
pollution.
In establishing the exposure-response function, we used
the GAM with R software to quantify the adverse health
effects of PM10. Different models can produce varying
estimates. We selected the GAM because it is more flexible, and allows nonparametric adjustments for nonlinear
confounding affects of seasonality, the weekday effect and
weather variables. Moreover, the R software was more
computationally steady than S-Plus software.
We found that although PM10 concentrations are
much higher in the Lanzhou urban area and the urban
population their experiences much greater exposure
than in other Chinese cities [36,48,49], the exposureresponse coefficientβis relatively small, suggesting weak
sensitivity of the population in local areas. The population structure of Lanzhou is different from that of
Europe and the United States where there is a larger
aging population; the elderly are an easily affected group.
Another reason may be that PM10 components are different from other areas. In developed countries and
areas, the main particle pollution source is automobile