Airborne particulates and polycyclic aromatic hydrocarbons (PAHs) in ambient air in Donghe, Northern China

Abstract

Five sets of size-fractionated particles were collected in a northern China village in various seasons in order to measure respirable airborne particulates (PM10) and particulate phase polycyclic aromatic hydrocarbons (PAHs) in ambient air. The time-weighted annual mean concentration and standard deviation of PM10 were 358 ± 107 μ g/m3, higher than both the national standard (100 μ g/m3) and the levels observed in several contaminated northern Chinese cities. In addition to high levels of PAHs (391 ± 487 ng/m3), the fraction of higher molecular weight PAHs was higher than most reported in the literature, and the time-weighted annual mean benzo(a)pyrene equivalent concentration was 44.2 ± 51.4 ng/m3, more than four times the national standard of 10 ng/m3 and 44 times the WHO guideline of 1 ng/m3. Apparently, residents in Donghe suffer from exposure to high levels of both PM10 and particulate phase PAHs. The particle size distribution was centered in the range of Dp ≤ 3.3 μm in winter and shifted to the ranges of Dp ≤ 2.1 μm and 5.8 μ m < Dp < 10 μm in spring and summer respectively. Approximately 90.0% of PAHs were associated with airborne particulates with Dp ≤ 2.1 μ m.