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Levels, profiles and gas–particle distribution of atmospheric PCDD/Fs in vehicle parking lots of a South China metropolitan area

Li, Huiru, Zhou, Lin, Ren, Man, Sheng, Guoying, Fu, Jiamo, Peng, Ping’an
Chemosphere 2014 v.94 pp. 128-134
air, air pollution, breathing, neoplasms, parks, petroleum, polychlorinated dibenzodioxins, polychlorinated dibenzofurans, principal component analysis, risk, urban areas, vapors, China, Japan
Vehicle exhaust is one important PCDD/F source in urban areas. In this study, occurrence and inhalation of atmospheric PCDD/Fs in three enclosed/semi-enclosed large-scale vehicle parks were investigated. The park for heavy-duty diesel-trucks exhibited the highest atmospheric 2,3,7,8-PCDD/F concentrations (17.7±4.3pgm−3, 0.818±0.264pg I-TEQm−3), followed sequentially by those for liquefied petroleum gas-buses and for unleaded gasoline-cars. High-chlorinated congeners/homologues dominated 2,3,7,8-PCDD/F profiles. Principal component analysis indicated their similarities with tailpipe studies. More than 70% of PCDD/Fs were particle-bound and their congener/homologue patterns differed from those of gaseous PCDD/Fs. In all studied parks logarithms of the gas/particle partitioning coefficients (Kps) of PCDD/F homologues were linearly correlated with those of their sub-cooled vapor pressures (pLs). Daily PCDD/F doses inhaled by park-workers were estimated to be between 0.099–0.227pg I-TEQkg−1d−1. Their probabilistic incremental lifetime cancer risks were 1.08×10−5–2.07×10−5, which were in the acceptable range (1.0×10−4–1.0×10−6). However, all data from the diesel-truck park significantly exceeded the upper limit for PCDD/Fs in ambient air of Japan (0.6pg TEQm−3). Hence, air pollution and adequate ventilation should be considered during the design and construction of such enclosed/semi-enclosed parks.