Research On Perfluoroalkyl Acid (PFAA) Contamination Status And Trend In The Sediments Of Typical Water Bodies And The Environment Around A Point Source

Research on Perfluoroalkyl Acid (PFAA) Contamination Status and Trend in theIn the past five decades, perfluorochemicals (PFCs),featured with perfluoroalkyl acids (PFAAs), have been employed universally in both industrial and domestic products, due to their special physicochemical characteristics.In recent years, these compounds have been detected in various environmental matrices, biota and human globally, resulting from their environmental persistence.Their existences have posed certain environmental risks to the ecosystems and human, in terms of their bioaccumulation and diverse toxicities.In 2009, perfluorooctane sulfonate (PFOS) and its salts together with its precursor, perfluorooctane sulfonyl fluoride (PFOSF), were consequently added to Annex B of the Stockholm Convention, calling for restricted production and use worldwide.Research on the occurrences and distributions of PFCs in China so far have been mainly focused on diverse water bodies, wet precipitation, biota, and non-occupationally PFCs-exposed populations, yet little is known about the current contamination status and features of sediment PFCs in typical water bodies within Chinese regions.In addition, sources of PFCs contaminations have not been identified in the previous research on the PFCs contaminations in ecosystem, environment, and non-occupationally exposed populations, it is thus necessary to carry on studies on the PFCs contaminations and distribution features in ecosystem, environment, and non-occupationally exposed populations around known PFCs point sources in China.The present study aimed to investigate the sediments from the Hun River, Taizi River, and Daliao River in the Liao River system, the Huangpu River in the Yangtze River Delta, the Zhujiang River in the Pearl River Delta of China, and the ecosystem, environment, and non-occupationally exposed populations around Fuxin fluorochemical industrial park. As a result, four conclusions could be drawn as follows.1)The total concentrations of PFCs were determined in the range of 0.19 to 1.0 ng/g dry weight (dw) in sediments from the Liao River system, and those in river water there were between 5.6 and 43 ng/L.PFOS was the dominant PFC contaminant in the sediments, while PFBS and PFOA were the dominant ones in the river water. An overall decreasing trend of PFCs contaminations with depth was observed in all the sediment cores from the three main streams of the Liao River system.2) The total concentrations of PFCs were determined between 0.09 and 3.6 ng/g dw in sediments from the Zhujiang River of Guangzhou, and those in sediments from the Shenzhen Bay and the Buji River of Shenzhen were between 0.22 and 0.54 ng/g dw. PFOS was the dominant PFC contaminant in the sediments from Guangzhou, while PFOA was the dominant one in the sediments from Shenzhen. The total concentrations of PFCs were determined between 0.25 and 1.1 ng/g dw in sediments from the Huangpu River of Shanghai, and those in sediments from the Lake Xuanwu and Qinhuai River of Nanjing were between 0.14 and 0.46 ng/g dw. PFOA was the dominant PFC contaminant in both the sediments from Shanghai and Nanjing.An overall decreasing trend of PFCs contaminations with depth was observed in all the sediment cores from the main water bodies of the Yangtze and Pearl River Deltas.3)Based upon the continuous monitoring on the PFCs contaminations in the wastewater and sediments from Shenyang Lingkong Canal at various time points, the levels of several PFCs in the wastewater fluctuated in the range of 30% to 1189%, while those in the sediments were relatively stable, indicating that the single sampling in the same water body at any time point might lead to over-or under-estimation of the PFCs levels in that water body, however, sediment might reflect the long-term PFCs contamination levels in a water body.4) Severe PFOA contamination with an increasing trend existed in the environment around Fuxin fluorochemical industrial park. The maximum concentration of PFOA in river and sediment were 668 ng/L and 48 ng/g dw, respectively;the highest PFOA concentration in groundwater beneath the park was 524 ng/L;the highest PFOA concentrations in the raw, finished, and drinking water of Fuxin were 16,2.7, and 1.7 ng/mL, respectively. One-compartment pharmacokinetic model indicated that, drinking water contributed 13% of the daily PFOA exposure in Fuxin. In human serum, PFOA had the geometric mean at 4.3 ng/mL,ranging from 0.02 to 93 ng/mL.The maximum concentrations of serum PFOA in chicken and ducks around the park were 3.0 and 15 ng/mL, respectively.As the dominant PFCs contaminations, the maximum concentrations of liver PFOS and PFOA in chicken and ducks there were 3.8 and 4.1 ng/g wet weight (ww),respectively.Results of the present study provide the current contamination status and trend of PFCs in typical water systems of China for the relative Chinese administrative sections, as the scientific bases for the environmental risk assessments and legislative controls for PFCs contaminations.In addition, it could provide supporting method and data for the long-term monitoring of PFCs point sources, contributing to minimize the potential risks of PFCs contaminations posed on the surrounding ecosystems and human health.