Extensive organohalogen contamination in wildlife from a site in the Yangtze River Delta

Statistical Survey of Persistent Organic Pollutants: Risk Estimations to Humans and Wildlife through Consumption of Fish from U.S. Rivers

U.S. EPA conducted a national statistical survey of fish tissue contamination at 540 river sites (representing 82 954 river km) in 2008-2009, and analyzed samples for 50 persistent organic pollutants (POPs), including 21 PCB congeners, 8 PBDE congeners, and 21 organochlorine pesticides. The survey results were used to provide national estimates of contamination for these POPs. PCBs were the most abundant, being measured in 93.5% of samples. Summed concentrations of the 21 PCB congeners had a national weighted mean of 32.7 μg/kg and a maximum concentration of 857 μg/kg, and exceeded the human health cancer screening value of 12 μg/kg in 48% of the national sampled population of river km, and in 70% of the urban sampled population. PBDEs (92.0%), chlordane (88.5%) and DDT (98.7%) were also detected frequently, although at lower concentrations. Results were examined by subpopulations of rivers, including urban or nonurban and three defined ecoregions. PCBs, PBDEs, and DDT occur at significantly higher concentrations in fish from urban rivers versus nonurban; however, the distribution varied more among the ecoregions. Wildlife screening values previously published for bird and mammalian species were converted from whole fish to fillet screening values, and used to estimate risk for wildlife through fish consumption.

Spatial distribution and bioaccumulation of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in snails (Bellamya aeruginosa) and sediments from Taihu Lake area, China

Taihu Lake area is one of the densest metropolitan areas in the world including diverse industrial activity. In the present study, the snail (Bellamya aeruginosa) and sediment were collected from the Taihu Lake area to investigate the contamination status, congener pattern, spatial distribution, and bioaccumulation effect of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The samples underwent liquid extraction, lipid removal by sulfuric acid, and acidic silica gel column, and subsequently analyzed by gas chromatography-electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). Concentration of ∑22PCBs ranged between 90 and 680 ng g-1 lipid weight in the snails and between 0.018 and 0.82 ng g-1 dry weight in the sediments. Concentration of ∑24PBDEs varied from 25 to 200 ng g-1 lipid weight in the snails and from 0.62 to 67 ng g-1 dry weight in the sediments. The levels of PCBs and PBDEs observed were in the medium to low range compared with other studies in the world. CB-153 was the predominant PCB congener in both snails and sediments whereas BDE-209 showed a low bioavailability in the snails, even if it contributed up to 70% of ∑24PBDEs in the sediments. The spatial distribution showed that the highest concentration of PCBs and PBDEs were detected in samples from Zhushan Lake. East Taihu Lake and Dianshan Lake showed lower concentration of PCBs and PBDEs than the other sampling sites. Biota-sediment accumulation was found between snails and sediments of most of PCB and PBDE congeners except for the highly brominated BDEs (i.e., BDE-209). Therefore, sediment is suggested to be an appropriate matrix to monitor BDE-209 while aquatic species such as the snail could be good for monitoring of PCBs and lower brominated BDE congeners. No significant correlation (Spearman correlation test, two-tailed) of CB-153 (r = 0.54, p = 0.27) or BDE-47 (r = 0.60, p = 0.21) was found between snails and sediments.

Human Exposure to Short- and Medium-Chain Chlorinated Paraffins via Mothers' Milk in Chinese Urban Population

Chlorinated paraffins (CPs) are high production volume synthetic chemicals, found ubiquitously in various environmental matrices. However, little information is available on CP contamination in mothers' milk. In this study, 1370 urban mothers' milk samples were collected from 12 Chinese provinces in 2007 and 16 provinces in 2011. CP geographical distribution and congener group profiles were studied to assess the CP levels and figure out the source of exposure in humans. Twenty-eight pooled samples were analyzed for 48 short-chain CP (SCCP) and medium-chain CP (MCCP) congener groups using the GC × GC-ECNI-HRTOFMS method. The median concentrations of SCCPs were 681 and 733 ng/g lipid in 2007 and 2011, respectively; median concentrations of MCCPs were 60.4 and 64.3 ng/g lipid in 2007 and 2011, respectively. Variations of more than 2 orders of magnitude in CP exposure levels were found between different provinces. The levels of CPs increased from 2007 to 2011, which indicates that CP production and use may be an important exposure source. This is the first global comprehensive and large-scale investigation of CPs in mothers' milk, and it lays foundations for improving our understanding of the metabolism of CPs in humans. The high CP concentrations found in Chinese mothers' milk should raise concern about potential toxic effects in both mothers and breastfeeding infants.