ASSOCIATION OF HEAVY METALS IN THE FINE PARTICLE AND LUNG FUNCTION IN AMBIENT AIR POLLUTION
Introduction: The heavy metals in air pollution particles are iron (Fe), manganese (Mn), zinc (Zn), lead (Pb), chromium (Cr), nickel (Ni), copper (Cu) and so on. These metals can contribute to lung injury,following exposure to air pollution particles.
Aim: The purpose of this study was to assess the exposure to concentrated metals in fine particles (i.e. PM2.5) and to determine whether lung function in children decreases following exposure to metals contained in particulate air pollutants.
Methods: Daily ambient concentrations of PM2.5 were collected for 40 days, during the spring season, at elementary schools in Beijing, China. These samples were analyzed for heavy metals such as Fe, Ni, Mn, Pb, and Zn by inductively coupled plasma emission spectroscopy (ICP). The pulmonary functions such as peak expiratory flow rate (PEFR), FEV1, FVC and FEV1/FVC were evaluated. One hundred children (50 boys and 50 girls, mean age: 10.4 years) participated in this study. The levels of PEFR in subjects were measured 3 times a day for the study period with baseline measurements of FVC and FEV1 were taken on the first day. Inference on air pollution and time effects of PEFR data were made by a mixed-model after adjustment for weather information such as temperature, humidity and atmospheric pressure.
Results: The mean concentrations of PM2.5, Fe, Ni, Mn, Pb, and Zn over the study period were 10.49±4.51, 0.72±0.22, 0.01±0.00, 0.04±0.02, 0.09±0.03, 0.12±0.04 μg/m3, respectively. The levels of PM2.5 were significantly correlated with individual heavy metals (P <0.01) and total heavy metals (P <0.01). The range of daily measured PEFR for this study was 213.1-545.5 L/min. Increase of individual or total heavy metal concentration (one day lag) was negatively associated with daily mean PEFR.