[Levels and Risk Assessment of Short and Medium-Chain Chlorinated Paraffins in Soil from Paper Mill Area].

Short-chain chlorinated paraffins are persistent organic pollutants, and chlorinated paraffins were widely used as sizing agent in the paper industry. In order to investigate the levels and risk assessment of short-chain and medium-chain chlorinated paraffins in the paper mill plant, the surface soil and soil of different depths were collected.The concentrations, congener group profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in soil were determined by two-dimensional gas chromatography coupled with electron capture-negative ion mass spectrometry. The SCCPs and MCCPs concentrations were 42-3853 ng·g-1 and 34-2091 ng·g-1. The chlorine contents were 59.9%-61.9% and 48.7%-52.8%. The concentrations of SCCPs and MCCPs were different in the soil collected in different sampling site. The concentration of SCCPs and MCCPs were relatively higher in soil of sewage treatment area and coating area. The CP levels in soil from the paper mill plant were at a high level compared with those in other regions. C10Cl6-7 and C14-15Cl5 were the main congener groups in most soil samples. The results of principal component analysis showed that the CP52 commercial products may be sources of SCCPs and MCCPs in the soil. The risk quotient (RQ) for SCCPs and MCCPs were assessed in soil of paper mill plant. The results showed that the RQ values for SCCPs in soil ranged from 0.01 to 0.73 which are the medium risk, and the RQ values for MCCPs in soil ranged from 0 to 0.07, which are the low risk. The human exposure values of children and adults are lower than TDI[10 µg·(kg·d)-1] in both cases. The health risks caused by non-dietary exposure under paper mill area are low.

Health risks posed to infants in rural China by exposure to short- and medium-chain chlorinated paraffins in breast milk.

Chlorinated paraffins (CPs) are complex mixtures of synthetic chemicals found widely in environmental matrices. Short-chain CPs (SCCPs) are candidate persistent organic pollutants under the Stockholm Convention. There should be great concern about human exposure to SCCPs. Data on CP concentrations in human breast milk is scarce. This is the first study in which background SCCP and medium-chain CP (MCCP) body burdens in the general rural population of China have been estimated and health risks posed to nursing infants by CPs in breast milk assessed. The concentrations of 48 SCCP and MCCP formula congeners were determined in 24 pooled human milk samples produced from 1412 individual samples from eight provinces in 2007 and 16 provinces in 2011. The samples were analyzed by comprehensive two-dimensional gas chromatography electron capture negative ionization high-resolution time-of-flight mass spectrometry. The median SCCP and MCCP concentrations were 303 and 35.7ngg-1 lipid weight, respectively, for the 2007 samples and 360 and 45.4ngg-1 lipid weight, respectively, for the 2011 samples. The C10 and C14 homologs were the dominant CP carbon-chain-length groups, contributing 51% and 82% of the total SCCP and MCCP concentrations, respectively. There are probably multiple CP sources to the general Chinese population and numerous exposure pathways. The median estimated daily SCCP and MCCP intakes for nursing infants were 1310 and 152ngkg-1d-1, respectively, in 2007 and 1520 and 212ngkg-1d-1, respectively, in 2011. SCCPs do not currently pose significant risks to infants in China. However, it is necessary to continuously monitor CP concentrations and health risks because CP concentrations in Chinese human breast milk are increasing.

[Pollution Characteristics and Risk Assessment of Polybrominated Diphenyl Ethers in the Surface Sediments from Middle Reaches of the Yangtze River].

Polybrominated diphenyl ethers (PBDEs) are highly lipophilic compounds with high toxicity and long-term bioaccumulation, which have strong affinities to suspended particulates in water. So PBDEs are easily adsorbed to sediments, and cause potential risks to human beings and aquatic ecosystem. In order to investigate the levels and patterns of PBDEs in the Yangtze River, 13 surface sediment samples were collected from the middle reaches of the regions and the concentrations of 9 PBDE congeners in the sediments were determined using High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS). The total concentrations of PBDEs ranged from 46.1 to 326 pg · g⁻¹ dry weight. BDE-99 and BDE-47 were the dominant PBDE congeners, which averagely contributed 51.6% and 19.6%, respectively. The concentrations of PBDEs were relatively low compared to those in other studies. The total organic carbon (TOC) was also analyzed in this study, and the results indicated that there was no obvious positive correlation between the levels of PBDEs and TOC. In addition, based on the PBDEs concentration levels, the ecotoxicological risks of PBDEs contamination in surface sediments of the Yangtze River were evaluated by the quotient method. The results showed that the levels of PBDEs were considerably low and these compounds should have no risk to human health.

[Levels distribution and risk assessment of the indicator and dioxin-like polychlorinated biphenyls in ten different species of marine fish of Bohai Bay, China].

Polychlorinated biphenyls (PCBs) are highly lipohilic compounds with high metabolic persistence and toxicity. PCBs tend to accumulate in the aquatic food chain and make fish a source of various environmental toxicants to humans. Industries in the Bohai Bay include iron and steel smelting, cement manufacturing and waste incineration, which are potential emission sources of PCBs. In this study, risks and potential effects of PCBs in the Bohai Bay were assessed. Twelve dioxin-like polychlorinated biphenyls (dl-PCBs) and seven indicator PCBs in marine fish samples were analyzed by High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS). The concentrations of dl-PCBs in marine fishes ranged from 28.9 pg x g(-1) to 1067.6 pg x g(-1) wet weight. The concentrations of indicator PCBs were between 185.5 pg x g(-1) and 8 371.7 pg x g(-1) wet weight. PCB-118 and PCB-105 were the major congeners of the dl-PCBs congeners, which contributed 41% - 56% and 15% - 21%, respectively. The predominant indicator PCBs were PCB-153 and PCB-138, which contributed 27% and 22%, respectively. The concentrations of dl-PCBs and indicator PCBs were relatively low as compared with those in other studies.

[Analysis of HCH in a typical waste contaminated site].

Soil samples in contaminated site of a historical HCH plant were collected and the levels and the distribution of HCH were analyzed and studied. The highest level of SigmaHCH was 271.72 mg kg(-1). The contamination of HCH was mainly in 0 - 40 cm depth of soil, while the concentration of HCH in 0 - 40 cm depth of soil was much more than that in 40 - 150 cm depth of soil. The concentration of beta-HCH was much more than other three kinds of isomers. The distribution of HCH in 0 - 20 cm depth of soil was calculated by Kriging model. The induration of the surface soil, which stopped the rainwater infiltrating, made theconcentration of HCH reduce with depth and made the depth of contaminated soil shallow.

Levels of polychlorinated biphenyls in 1,4-dichlorobenzene mothballs.

Although polychlorinated biphenyls (PCBs) are globally recognized pollutant, an understanding of their resources as by-products in chemical industry is poorly investigated. This paper presents data from a study that was conducted in order to determine the extent of PCBs in 1,4-dichlorobenzene( p-DCB) mothballs. Total PCBs and dioxin-like PCBs were detected in five mothball samples. Total PCB concentrations ranged from 328 ng/g to 1798 ng/g, while the levels of WHO-TEQ were between 0.16 pg/g and 13 pg/g. Mean concentrations of total PCBs and WHO-TEQ in the samples were 724 ng/g and 3. 2 pg/g, respectively. The highest level of PCB congeners was that of trichlorinated biphenyls (537 ng/g), which maybe due to the relatively low chlorination in the process of p-DCB production. A mechanism of the formation of PCBs from polychlorinated benzene in the presence of chlorine is also suggested. The results suggested that re-estimation on the risk of p-DCB products, especially the products for daily use such as mothballs, is expected.

[Speciation analysis of mercury in traditional Chinese medicine by vapor-generation atomic fluorescence spectrometry].

A sensitive method has been proposed for the determination of inorganic mercury and total organic mercury in traditional Chinese medicine (Wanshi Niuhuang Qingxin) by vapor-generation atomic fluorescence spectrometry. The experimental conditions that influence the atomic fluorescence signal intensity of Hg and the oxidization of organic mercury were investigated and optimized. Thiourea citric acid was selected as a sensitization agent, which greatly enhanced atomic fluorescence signal intensity of mercury. The influence of foreign ions and their elimination were studied. The detection limit of the method for Hg was 7.6 ng x L(-1) and the relative standard deviation was 1.56%-3.28% for Hg. The proposed method was successfully applied to the determination of mercury speciation in real samples with a recovery range of 90.3%-110.3%.

[Speciation analysis of arsenic in traditional Chinese medicines by hydride generation-atomic fluorescence spectrometry with ion exchange resin separation].

A method for the determination of arsenic species (arsenide, arsenate) in traditional Chinese medicines using hydride generation atomic fluorescence spectrometry (HG-AFS) with ion exchange resin separation has been studied. The ion exchange resin was used to separate the arsenide and arsenate, and the separation conditions were investigated. The experimental conditions that influence the fluorescence intensity and the reduction of arsenic(V) were investigated and optimized, and the influence of foreign ions and its elimination were studied. The proposed method was applied to the determination of arsenic species in water leachate of traditional Chinese medicines. A detection limit of 89.1 ng x mL(-1) and a recovery range of 91.1%-109.3% were obtained.

Speciation analysis of arsenic in traditional Chinese medicines by hydride generation-atomic fluorescence spectrometry.

A method has been described for the determination of arsenic species (arsenite and arsenate) by hydride generation-atomic fluorescence spectrometry (HG-AFS). The experimental conditions that influence the fluorescence intensity and the reduction of arsenic were investigated and optimized, and the influences from foreign ions and their elimination were studied. The detection limit was found to be 79.7 ng L(-1). The proposed method was applied to the determination of arsenic species in water leachate of traditional Chinese medicines with a recovery range of 91.1-109.5%.