physiochemical characteristics and oxidative potential of ambient air particulate matter (pm10) during dust and non-dust storm events: a case study in tehran, iran

In the present study, we investigated the characteristics of metal(loid)s, polycyclic aromatic hydrocarbons (pahs) and oxidative potential (op) in pm10 during dust and non-dust days in a rural and an urban area in tehran. water-soluble ions, metal(loid)s, pahs, and op were measured using ion chromatography (ic), inductively coupled plasma optical emission spectrometer (icp-oes) and gas chromatography/mass spectrometry (gc-ms), and dithiothreitol (dtt) assay respectively. the results showed that the average concentrations of ambient pm10 were 284 ± 90.4 and 123 ± 31.4 μg m−3 on dusty and regular days in urban areas respectively, and were 258 ± 48.3 and 124 ± 41.4 μg m−3 on dusty and regular days in rural areas, respectively; these values were 95% above the world health organization (who) guideline level. the crustal elements na+, mg2+, ca2+, al, si, fe and ti were the dominant for pm10 on dusty days, and no−3 and so42− were dominant for pm10 on regular days. the average ± sd concentrations of total pahs were 34.3 ± 22.5 and 55.1 ± 28.3 ng m−3 on dusty and regular days, respectively, with the maximum value occurring on inversion days. the average op was 8.90 ± 7.15 and 1.41 ± 0.35 and was 11.4 ± 3.97 and 19.9 ± 8.67 (nmol min−1 μg pm10−1) for water and methanol extracts on dusty and regular days, respectively, with the lowest value occurring on dusty days. the op was highly associated with cu and mn. briefly; the results of this study demonstrate that op is mass independent and consequence a promising proxy for pm mass.