Distribution of persistent organochlorine pesticides in tissue/organ of silver carp (Hypophthalmichthys molitrix) from Guanting Reservoir, China.

The concentration of organochlorine pesticides (OCPs) in tissues and organs of silver carp (Hypophthalmichthys molitrix) from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight (ww) for total OCPs, 0.16-0.75 ng/g ww for. HCB, 0.75-26.80 ng/g ww for sigmaHCH (sum of alpha-, beta-, gamma- and delta-HCH) and 0.68-35.94 ng/g ww for sigmaDDT( sum of p, p'-DDE, p, p'-DDD, o, p'-DDT and p, p'-DDT). The mean concentrations of total OCPs, HCB, sigmaHCH, and sigmaDDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, beta-HCH and p, p'-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.

[Level, composition and sources of medium-chain chlorinated paraffins in soils from Chongming Island].

In order to understand the contents, spatial distribution and sources of medium-chain chlorinated paraffins (MCCPs) in the soils from Chongming Island, the concentrations of MCCPs in 27 soil samples were analyzed by GC-ECNI-MS. The total concentrations of MCCP8 (sigma MCCPs) in all samples ranged from 2.56-96.3 ng x g(-1), with a median of 7.32 ng x g(-1). All soil samples were classified into two categories by cluster analysis. C14-MCCPs and C15-MCCPs, and Cl5-MCCPs and Cl6-MCCPs were the most predominant carbon and chlorine congener groups in most of the samples, accounting for 29.8% and 28.9%, and 29.9% and 23.3%, respectively. C14-MCCPs were the most predominant carbon congener groups in some samples, accounting for 68.5%, which was similar to that of CP-52. Atmospheric deposition and soil-air exchange were the major sources of MCCPs for soils in Chongming. Soils at a few sites were probably contaminated by sewage sludge from sewage treatment plants (STPs) or other unidentified source. No significant correlations were observed between MCCPs and TOC. The correlation analysis also showed significant correlation among the carbon congener groups of MCCPs, which suggested that MCCP congener groups might have been derived from similar sources. Compared to other studies at home and abraod, the MCCPs concentrations in the present study were at a lower level.

[Levels, distribution and possible sources of polychlorinated biphenyls in river sediments from an electronic waste recycling area].

The concentrations of 144 polychlorinated biphenyls (PCBs) in the river sediments from Luqiao were analyzed by GC-muECD. The objectives of this study were to understand the contents, spatial distribution and possible sources of PCBs. The Sigma PCBs concentrations detected in the river sediments were in the range of 1.66 to 5 930 ng x g(-1), with a mean of 763 ng x g(-1). Tri-CBs, tetra-CBs and penta-CBs were the primary PCB congeners in all samples, accounting for 2.63%-57.6%, 10.4%-54.6% and 7.82%-46.1%, respectively. Octa-CBs and deca-CBs were the minor PCB congeners in all samples, with the percentages of 0-8.57% and 0-11.0%, respectively. The hierarchical cluster analysis (HCA) showed that 22 samples were mainly polluted by Ar1248, 9 samples were polluted by Ar1254, and 6 samples were contaminated by Ar1016, Ar1232 and Ar1242. The PCBs concentrations found in the present study were at an upper-middle level compared with those in other studies in the world. The PCBs pollution in the present area had a high ecological risk.

[Level, distribution, and source identification of polychlorinated naphthalenes in surface agricultural soils from an electronic waste recycling area].

The concentration of 46 polychlorinated naphthalenes (PCNs) in the agricultural soils from Luqiao was analyzed by GC-NCI-MS. The objectives of this study were to investigate the contents, spatial distribution and sources of PCNs. The total concentrations of PCNs (sigma PCNs) in soil samples were in the range of 0.062 to 2.92 ng x g(-1), with a mean of 0.630 ng x g(-1). Tetra-CNs and penta-CNs were the predominant homologues in most of the samples, accounting for 18.4% - 88.8% and 8.40% - 53.1%, with average values of 46.7% and 30.7%, respectively, followed by tri-CNs, accounting for 0 - 47.3%, with a mean of 10.6%. Cluster analysis and combustion marker analysis showed that the sampling sites were mainly polluted by Halowax 1014 and Halowax 1013, also possibly polluted by PCBs mixtures and e-waste combustion process. Compared to other studies, the PCNs concentration in this study was at a medium level.

[Characteristics of polychlorinated biphenyls in soils from an electronic waste recycling area].

The concentrations of 144 polychlorinated biphenyls (PCBs) in the soils from Luqiao were analyzed by GC-microECD. The objectives of this study were to understand the contents, spatial distribution and sources. The sigma PCBs concentrations in soils samples were in the range of 0.779 ng x g(-1) to 937 ng x g(-1), with a mean of 75.7 ng x g(-1), and the relatively high level of PCBs were mainly distributed in the south central area. Penta-CBs, hexa-CBs and tetra-CBs were the primary homologues in 38 samples, with the range of 13.0% - 61.1%, 4.59% - 48.8% and 10.1% - 31.5%, respectively. Di-CBs was the most predominant homologues in other samples, with the range of 47.1% - 75.2%. The hierarchical cluster analysis (HCA) showed that most of samples were mainly polluted by Ar1254, few samples were polluted by Ar1221. Significant correlations were observed between sigma PCBs and TOC, which suggested PCBs were affected by TOC in soils. The correlation analysis also showed significant correlation among the PCBs homologues (except di-CBs and nona-CBs), which suggested PCBs might have the similar sources. Compared to other studies from different countries and regions, the PCBs concentrations in the present study were at an upper-middle level.

[Levels, distribution and possible sources of polybrominated diphenyl ethers in river sediments from an electronic waste recycling area].

The concentrations of 41 polybrominated diphenyl ethers (PBDEs) in the river sediments from Luqiao were analyzed by GC-NCI-MS. The objectives of this study were to understand the contents, spatial distribution and sources. The Sigma40 PBDEs (excluding BDE209) concentrations in sediments sampled were in the range of 0.177 to 161 ng x g(-1), with a mean of 22.5 ng x g(-1), and the concentrations of BDE209 were from 0.36 to 958 ng x g(-1), with a mean of 148 ng x g(-1). Deca-BDE was the most predominant in 9 PBDE homologues in most of samples, accounting for 38.4%-96.0%, with an average of 74.4% nona-BDEs and hepta-BDEs, accounting for 3.3%-25.8% and 0.01%-14.1%, respectively. Significant correlations were observed among all of PBDEs congeners, which suggested these PBDEs might have the similar sources. The homologue composition of PBDEs and hierarchical cluster analysis (HCA) showed that most of sampling sites were mainly polluted by deca-BDE formulation, and others polluted by deca-BDE and octa-BDE formulations. Compared to other studies from different countries and regions, the PBDEs concentrations in the present study were at a medium-to-low level. But it should be concerned that a few of sampling sites were highly contaminated by point sources.

[Residues of organochlorine pesticides in urban soil of Shanghai].

The 55 soil samples were collected from Shanghai urban areas in March 2007. The residues and distribution characteristics of organochlorine pesticides (OCPs) in the soil samples were investigated with gas chromatography. The results showed that HCHs, DDTs, and HCB were in the ranges of nd-38.58 microg x kg(-1), 1.81-79.61 microg x kg(-1) and 0.16-40.25 microg x kg(-1), respectively. The total OCPs concentrations in urban soil of Shanghai ranged from 3.12 microg x kg(-1) to 91.07 microg x kg(-1) with a mean of 22.33 microg x kg(-1), and the p,p'-DDE took over 60% of the total OCPs. The main contaminated areas were distributed in the park and greenbelts. The composition of OCPs indicated that OCPs in soil samples mainly came from historical application. Compared to the reference data, the pollution burden in soil of Shanghai was lower than those in other areas of China and in German, Argentina and Poland.

[Distribution, possible source and ecological risk assessment of polycyclic aromatic hydrocarbons in river sediments from a typical contaminated area].

The concentrations of 16 US EPA PAHs in 37 sediment samples collected from Luqiao were analyzed by isotope dilution gas chromatograph/mass spectrometer (GC/MS), and their distribution characters,sources and ecological risk were further investigated. Each of the 16 PAHs could be detected in all of the sediment samples, the total concentrations of the 16 PAHs in the sediments ranged from 59.3 microg/kg to 3 180 microg/kg,with a mean of 722 microg/kg. The pollution level of PAHs can be categorized as low to moderate when compared with other studies around the world. SigmaPAHs were significantly correlated with TOC (r = 0.699, p < 0.001), indicating that TOC was a key soil property affecting the level and fate of PAHs in sediments. The isomeric ratios and factor analysis revealed that PAHs in the Luqiao sediments were originated from mixed sources, and combustion source was dominant. Six sampling sites had the mean PAH ERL quotient > 1, indicating that some sediments in Luqiao may have potential ecological risk. The toxic benzo[a]pyrene equivalents (TEQ(BaP)) of the 16 PAHs ranged from 3.41 microg/kg to 485 microg/kg, 98.4% of which was contributed by 7 carcinogenic PAHs, indicating that 7 PAHs were the main influential factors to the ecological risk.