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Abstract: Atmospheric particulate and polycyclic aromatic hydrocarbon (PAH) size distributions were measured at a suburban area in central Taiwan during the rice straw burning and non-burning periods. Samples were acquired using a semi-volatile sampling train (PS-1 sampler) and a micro-orifice uniform deposit impactor (MOUDI). The collected materials were extracted and then analyzed by gas chromatograph/mass selective detector for 21 PAHs. The average total PAH concentrations of particulate and gaseous phases were 33.0 and 1160ngm−3, respectively, in the rice straw burning period, which were higher than those on the non-burning days. Potential sources of PAHs were identified using the characteristic ratios. Benzo[a]pyrene/benzo[ghi]perylene ratio indicates the burning of rice straw is a significant source for PAH contribution at the sampling area. It also suggests that the rice straw burning primarily contribute fine particulate PAHs. Bimodal size distributions are obtained with a predominance of total PAHs in the accumulation mode during rice straw burning periods and in ultra-fine mode during non-burning periods. The particulate and particulate phase PAHs from rice straw burning are coarser than those from vehicle exhaust. The results also suggest that the amounts of PAHs per unit mass of particulate are less for the burning of rice straw than those of vehicle emissions. [Copyright &y& Elsevier]

Abstract: Cooking exhausts may contribute significant organic compounds to the atmosphere. It has been shown that trans,trans-2,4-decadienal (tt-DDE) is an important toxic compound in cooking oil fumes (COF). In this study, the emissions of tt-DDE were quantified in both gaseous and particulate phases of three kinds of restaurant exhausts (Chinese, western and barbecue). Samples of exhausts were collected with a sampling system meeting the criteria of US EPA Modified Method 5. The tt-DDE was analyzed by HPLC–MS/MS. The results indicate that the emission factors of tt-DDE in terms of μgcustomer−1 were in sequence: barbecue (1990)>Chinese (570)>western (63.8). The average proportion of tt-DDE in the particulate phase of the exhausts was 83% for the 16 investigated restaurants. Evidently, the majority of tt-DDE in the exhausts was in the particulate phase. There was no evident correlation found between phase distribution of tt-DDE and exhaust temperature in the restaurants investigated. The efficiencies of removal of particulate tt-DDE by air pollution control devices (APCDs) were assessed. The removal efficiencies of electrostatic precipitator (ESP), ESP and activated carbon in series, and wet scrubber were 64.2%, 86.3% and 71.3%, respectively. [Copyright &y& Elsevier]