Characterization, risk assessment and potential source identification of PM10 in Tehran

This study was performed to investigate the concentration and the health risk of metal(loid)s, polycyclic aromatic hydrocarbons (PAHs) and Water-soluble ions in PM10 during cold and warm seasons in two different stations, rural and an urban area at Tehran. The characterization of the metal(loid)s, PAHs and Water-soluble ions associated to the PM10 were carried out by inductively coupled plasma optical emission spectrometer (ICP-OES), gas chromatography/ mass spectrometry (GC-MS) and ion chromatography (IC), respectively. The average concentrations of ambient PM10 on cold and warm seasons were 79.6 and 67.9 mu g/m(3) in urban area and 57.3 and 58.8 mu g/m(3) in rural area, respectively. The elements from crustal source (Na+, Mg2+ , Ca2+, Al, Si, Fe and Ti) were the major compositions for PM10 in warm season, and NO3- and SO42- were major component of PM10 in cold season at both sites. The mean concentrations of total PAHs were found to be 103.8 +/- 81.2 and 67.1 +/- 28.1 ng/m(3) on cold and warm seasons for the urban area, and 31.85 +/- 18.91 and 26.61 +/- 15.72 ng/m(3) in cold and warm seasons for the rural area, were indicative of the significance of mobile sources in Tehran. Results from this study indicate that for both sites, the carcinogenic risk caused by inhalation pathway PM10 bound PAHs exceeded the acceptable level of world health organization safe limits, indicating the need for more investigation to reducing potential carcinogenic risk.