Health Impact Assessment of PM2.5 control legislation in Korea

Abstract

BACKGROUND AND AIM: Exposure to PM2.5 has been associated with increased all-cause mortality. The metropolitan area particulate matter reduction policy is enacted to reduce PM2.5 concentration in 2008. The policy selected substances subject to particulate matter management, implemented total emission regulations in Seoul and Incheon, strengthened standards for allowing emissions for production vehicles, and promoted reduction of diesel car emissions. The aim of the present analysis is to evaluate the effectiveness of the policy on health. METHODS: The policy was applied to Seoul and Incheon, and other metropolitan cities in Korea were selected as control groups. We conducted interrupted time series analyses to examine changes in PM2.5 concentration and concentration-response function after the enactment of the policy. Based on the calculated change, we estimated the health benefit in terms of reduced mortality. RESULTS:We observed a decrease in the slope of concentration-response function of all-cause mortality after intervention in Seoul and Incheon. PM2.5 concentrations also decreased. The interaction coefficient about intervention was -0.537 (p value=0.001) in Seoul and -0.0276 (p value=0.64) in Incheon. We calculated the number of excess deaths when there was no intervention effect, when only PM2.5 concentrations were decreased, when only concentration-response function was decreased, when both concentration-response function and PM2.5 were reduced. The number of excess death in Seoul was 684.1 (221-1112.3), 654 (230.1-1149.1), 450.9 (0-883.1), and 432.2 (0-919.1), respectively. We observed 137.1 (0-673.4), 113.8 (0-560.7), 82 (0-236.2), and 68.7 (0-196.7), in Incheon, respectively. CONCLUSIONS:The all-cause mortality caused by PM2.5 in Seoul and Incheon decreased after intervention. KEYWORDS: All-cause mortality, Health impact assessment, Legislation, PM2.5 concentration, Excess death