Distribution, partitioning and inhalation exposure of perfluoroalkyl acids (PFAAs) in urban and rural air near Lake Chaohu, China

Abstract

To investigate the distribution, partitioning, and inhalation exposure risks of perfluoroalkyl acids (PFAAs), gaseous and particulate samples were collected monthly between September 2013 and September 2015 in urban and rural areas near Lake Chaohu. Twelve PFAAs were determined by liquid chromatography-mass spectrometry. The mean concentrations of PFAAs in the gaseous phase and the particulate phase were 40.31 ± 31.47 pg/m3 and 63.26 ± 41.87 pg/m3, respectively. Perfluorobutanoic acid (PFBA) was the predominant contaminant in the gaseous phase (32.56% ± 9.28%), while perfluorooctanoic acid (PFOA) was the main contaminant in the particulate phase (33.21% ± 18.69%). The ratios of gaseous to particulate distribution ranged from 0.01 to 16.75. The gaseous-particulate partitioning coefficients, ranging from 0.01 to 23.41 ± 10−2 m3/μg, were significantly correlated with PM10 concentrations and meteorological conditions, such as temperature and air pressure. The inhalation exposures of PFOA and PFOS were 1.94–60.2 pg/(kg·d) and 0.30–4.22 pg/(kg·d), respectively. The carcinogenic risk of PFOA for urban males was the highest and that for rural females was the lowest; the risks were lower than the acceptable level (10−6) defined by the US Environmental Protection Agency (USEPA). The non-carcinogenic risks of PFOA and PFOS were far below one.