Heavy Metal Components in Atmospheric Fine Particulate Matter before and after the Coal-Fired Power Plants Shut Down in Beijing, China

Abstract

Background/Aim: Many studies have indicated that some heavy metal components in fine particulate matter (PM2.5) could cause adverse effects on human health. To reduce the atmospheric particle pollution and improve the air quality, four of the five coal-fired power plants (CFPP) in Beijing, which is an important source of ambient PM2.5, have been shut down. The aim of this study was to compare the difference of heavy metal components in atmospheric PM2.5 before and after the CFPP were shut down during the winter heating season in Beijing, China. Methods: The ambient sampling site was set in a main district of Beijing. December 2012 to January 2013 and December 2015 to January 2016 were chosen as two sampling periods, in which at least 15 days were selected for the PM2.5 continuous sampling before and after the CFPP were shut down respectively. The membrane weighing method was used to determine the PM2.5 mass concentration and the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for the measurement of the heavy metal components of the samples. Results: The average daily concentration of PM2.5 was 133.75µg/m3 and 110.64µg/m3 before and after the CFPP were shut down, respectively. After the CFPP were shut down, the concentrations of arsenic, cadmium, plumbum and zinc reduced by 90.4%, 66.7%, 66.7% and 62.5%, and the mass percentage in PM2.5 decreased by 85.9%, 40.7%, 48.9% and 30.0%, respectively. The proportion of days with concentration of PM2.5 less than 75 µg/m3 (WHO Interim target-1) increased from 38.7% to 46.8% and days with high levels of pollution (PM2.5 ≥ 150 µg/m3) decreased from 37.1% to 29.0%. Conclusions: The heavy metal contents in PM2.5, especially arsenic, could be obviously reduced by shutting down the CFPP, which is meaningful for the residents because of the reduction of health risk.