Nan Gai

Perfluorinated compounds in soil, surface water, and groundwater from rural areas in eastern China.

Little research on perfluorinated compounds (PFCs) has been conducted in rural areas, although rural PFC sources are less complicated than in urban and industrial areas. To determine the levels and geographical distribution of 17 PFC compounds, samples of soil, surface water, and groundwater were collected from eight rural areas in eastern China. The total PFC concentrations (∑PFCs) in soils ranged from 0.34 to 65.8 ng/g ∑PFCs in surface waters ranged from 7.0 to 489 ng/L and ∑PFCs in groundwater ranged from 5.3 to 615 ng/L. Ratios of perfluorononanoic acid/perfluorooctanoic acid (PFNA/PFOA), perfluoro-n-butyric acid/perfluorooctanoic acid (PFBA/PFOA), and perfluoroheptanoic acid/perfluorooctanoic acid (PFHpA/PFOA) in rainwater increased due to the fluorine chemical plants in the surrounding rural and urban areas, suggesting that atmospheric precipitation may carry PFCs and their precursors from the fluorochemical industrial area to the adjacent rural areas.

Organochlorine pesticides and polychlorinated biphenyls in grass, yak muscle, liver, and milk in Ruoergai high altitude prairie, the eastern edge of Qinghai-Tibet Plateau.

In highland pastures, where no agricultural and industrial activities exist, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are believed to be mainly coming from water-soil-grass system which is subject to air-water and air-soil exchanges and atmospheric precipitation. Samples of grass and yak muscle, liver, and milk were measured for OCPs and PCBs in the summer and winter of 2011. The total concentrations of HCHs, DDTs, endosulfans, HCB, and PCBs in grass samples were in the range of 0.53-2.45, 1.6-6.0, 1.10-4.38, 0.30-1.24, 0.65-2.04 ng g(-1) dw (dry weight), with the means 1.38, 2.86, 2.06, 0.73, and 1.19 ng g(-1) dw, respectively. The mean concentrations of HCHs and DDTs in yak muscle were 1.65 and 0.55 ng g(-1) fw (fresh weight), respectively; no significant seasonal differences. The average total concentrations of HCHs, DDTs, HCB, endosulfans, and PCBs in yak milk were 4.46, 0.59, 1.00, 0.27, and 0.097 ng g(-1) fat, respectively. Among the POPs investigated, β-HCH and HCB were dominant in yak muscle and liver, whereas β-HCH dominated the yak milk. Consistent with the results of other studies, PCB 153, 138, and 180 were detected in yak milk that is in accordance with the case reported for farmed cow milk in China and other countries. A human health risk was conducted based on the intake of OCPs via consumptions of the yak muscle and milk. Since the daily intake of HCHs and DDTs was lower than WHO or USEPAs acceptable daily intake or minimal risk level, showing that the consumptions of the yak muscle and milk would not pose any immediate risk to local people.