Recently, frequent hazy weather across China rose great public concern about health consequences of air pollution. Among different air pollutants, ambient fine particles (PM_(2.5)) became the focus partly due to its strong adsorption of nocuous substances like Pb and Cd, which will do serious harm to human health through affecting body's nervous, immune, cardiovascular system, etc. Many studies have analyzed the composition and sources of metal elements in PM_(2.5). However, few of them have explored spatial-temporal variations, specifically for a school in China. With the support from STEM (Science, Technology, Engineering and Mathematics) program directed by Nanjing Foreign Language School, this study measured the metals in PM_(2.5). Specifically, we selected the playground and classroom in Nanjing Foreign Language School as sample sites for outdoor and indoor environment. Samples were collected by the portable particulate monitor (MicroPEM, RTI International) for four seasons. For each site in each season, there were three samples with 24-hours continuous monitoring PM_(2.5) data. Then, all samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to characterize six typical metal elements, including Pb, Mn, Cu, Cr, Sb and Ni. Results showed that spatial and temporal distribution of metals in PM_(2.5) followed some rules. The concentrations of most metals were higher in spring and winter, lower in summer and autumn. Outdoor metal contents were significantly higher than indoor in spring and winter, probably because closed indoor environment in cold days significantly hindered penetration of outdoor pollutants. In addition, Pb is the dominated metals in PM_(2.5) in Nanjing mainly due to vehicle emissions. From the results, the government should pay more attention to pollutant sources like motor vehicle. And it is recommended for individuals to take action like wearing masks or staying indoors so as to reduce damage to their health in spring and winter.
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