Persistent organic pollutants (POPs) have been associated with a wide range of adverse health effects. Our case-control study was performed to explore the association between placental levels of selected POPs and risks for neural tube defects (NTDs) in a Chinese population with a high prevalence of NTDs. Cases included 80 fetuses or newborns with NTDs, whereas the controls were 50 healthy, nonmalformed newborn infants. Placental concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers were analyzed by gas chromatography-mass spectrometry. The medians of PAHs, o,p'-isomers of dichlorodiphenyltrichloroethane (DDT) and metabolites, alpha- and gamma-hexachlorocyclohexane (HCH), and alpha-endosulfan were significantly higher in case placentas than in controls. PAH concentrations above the median were associated with a 4.52-fold (95% confidence interval (CI), 2.10-9.74) increased risk for any NTDs, and 5.84-(95% CI, 2.28-14.96) and 3.71-fold (95% CI, 1.57-8.79) increased risks for anencephaly and spina bifida, respectively. A dose-response relationship was observed between PAH levels and the risk of NTDs, with odds ratios for the second, third, and fourth quartiles, compared with the first, of 1.77-(95% CI, 0.66-4.76), 3.83-(95% CI, 1.37-10.75), and 11.67-fold (95% CI, 3.28-41.49), respectively. A dose-response relationship was observed for anencephaly and spina bifida subtypes. Similar results were observed for o,p'-DDT and metabolites, alpha-HCH, gamma-HCH, and alpha-endosulfan, whereas no dose-response relationship was observed for the last two pollutants. Elevated placental concentrations of PAHs, o,p'-DDT and metabolites, and alpha-HCH were associated with increased risks of NTDs in this population.

Investigations on residues of organochlorine pesticides(OCPs) in soils in Huizhou,China were conducted.A total of 42 soil samples were collected from sites representative of the region for analysis of contents of OCPs.And with the aid of multi-variate geostatistics and GIS,residue and spatial distribution of 17 types of OCPs were analyzed.Results show that the 17 OCPs were detected,various in content in all the soil samples.HCHs and DDTs residues were detected,but below the criteria of the national standards for soil environment quality.Residue content of beta-HCH was the highest among HCHs,which implied some recent input of HCH to soils,while for DDT,no sign of new input was found.Compared with other regions in the country,Huizhou city was lower in soil HCH and DDT content.Principal component analysis demonstrated that the above-said 17 OCPs in the soil may have 5 major contributors,corresponding respectively to industrial use of HCH,natural factors,use of lindane,use of heptamul and use of Drinox.By means of ordinary Kriging interpolation,spatial distribution of OCPs was studied with results indicating that the 17 OCPs variaed greatly in spatial distribution between types选取位于珠江三角洲的惠州市为研究区域,对该市土壤进行了系统采样分析,测定了42个表层土壤样品中的17种有机氯农药的含量.利用多元地统计和GIS相 结合的方法,研究了17种有机氯农药的残留状况及空间分布情况.结果表明,17种有机氯农药在42个土壤样品中均有不同程度的检出,其中p,p′-DDE 检出率为100%,3种有机氯农药检出率在90%以上,6种有机氯农药的检出率在80%以上.其中六六六和滴滴涕残留较普遍,但并未达到污染水平.分析显 示,近期可能仍有新的六六六输入土壤环境,而滴滴涕则主要来自过去施用农药的残留.与国内其他地区比较,惠州市土壤HCH和DDT含量处于较低水平.主成 分分析显示上述17种有机氯农药可以由5个主成分反映,分别对应于工业HCH的使用,自然因素,林丹的使用以及七氯和艾氏剂等农药的使用.采用克里格插值 法对有机氯农药在研究区的空间分布进行了研究,结果表明不同有机氯农药在研究区分布存在很大差异

Dichlorodiphenyltrichloroethane (DDT) has been banned in China for decades, and yet high DDT concentrations are still being detected in the Chinese environment. This might be at least partly due to the current use of dicofol formulation, which contains DDT as an impurity. In this study, a method based on the ratios of two DDT isomers, o,p '-DDT and p,p '-DDT, was established and used to estimate the relative contributions of dicofol formulation and those of technical DDT to overall environmental DDT. Based on this method and field data from the literature, we calculated that dicofol formulation contributed >72% of atmospheric DDT in 2004 in the Taihu Lake region, China, and this value was >84% in summer when dicofol was applied for agricultural purposes. Sediment and soil, however, contained mostly residual DDT from the historical use of technical DDT. In most other regions of China, we found that dicofol contributed to a significant fraction of DDT in air samples. (C) 2010 Elsevier Ltd. All rights reserved.

Air and water samples were collected from Taihu Lake, East China through 2004 and analyzed for 33 congeners of polybrominated diphenyl ether (PBDE) and other seven brominated and chlorinated flame retardants. The annual concentration of total atmospheric PBDEs was 220 pg m(-3); BDE-209 was most abundant (average 41% of total PBDEs), followed by BDE-47 (17%) and BDE-28 (15%). The relative abundance of tetra- and tri-BDE congeners (including BDE-47, -28, -49, -66, and -17) instead of BDE-99 indicated that a specific penta-BDE formulation might be produced and/or consumed in this region. The source was confirmed by the analysis of air-water gas exchange, which was nearly at equilibrium in spring and summer but displayed strong volatilization flux in autumn and winter, especially for BDE-28, indicating the potential wastewater discharge of PBDEs into the lake. In addition to PBDEs, hexabromobenzene, 1,2-bis(2,4,6-tribromophenoxy)ethane, decabromodiphenylethane, and Dechlorane Plus were detected in air samples, with an annual mean concentration of 23 pg m-3 for decabromodiphenylethane, and <4 pg m(-3) for the others. (C) 2010 Elsevier Ltd. All rights reserved.

In this study,investigations were conducted on residues of organochlorine pesticides(OCPs)in soils in Zhanjiang city,China.A total of 61 soil samples were collected from sites which were representative of the region for analysis of contents of OCPs.And with the aid of multi-variate geostatistics and GIS,residues and spatial distributions of 17 types of OCPs were analyzed.Results show that the 17 OCPs were detected.various in contents of allthe soil samples.HCHs and DDTs residues were below the criteria of the national standards for soil environment quality.Residue content of 13-HCH was the highest among HCHs,indicating some recent input of HCH to soils,while for DD T,no sign of new input was found.Principal component analysis demonstrated that the 17 OCPs in the soil may have 6 major contributors,corresponding respectively to the use of industrial HCH and lindane,plant diseases and insect pests and the pesticide use,etc.By means of ordinary Kriging interpolation,studies on spatial distribution of OCPs showed that the 17 OCPs varied greatly in spatial distribution between types.选取位于中国大陆最南端的湛江市为研究区域,对该市土壤进行了系统采样分析,测定了61个表层土壤样品中的17种有机氯农药的含量.利用多元地统计和GI S相结合的方法,研究了17种有机氯农药的残留状况及空间分布情况.结果表明,17种有机氯农药在42个土壤样品中均有不同程度的检出,其中P,P'-D DE检出率为100%,3种有机氯农药检出率在90%以上.其中六六六和滴滴涕残留较普遍,六六六未达到污染水平,有一个土壤样品滴滴涕超过国家土壤环境 质量一级标准.分析显示,近期可能仍有新的六六六输入土壤环境,而滴滴涕则主要来自过去施用农药的残留.主成分分析显示17种有机氯农药町以由6个主成分 反映,分别对应于工业HCH和林丹的使用、农药使用习惯以及当地病虫害特点等.采用克里格插值法对有机氯农药在研究区的空间分布进行了研究,结果表明不同 有机氯农药在研究区分布存在很大差异.

At 14: 28 on 12 May 2008, Sichuan Province of China suffered a devastating earthquake measuring 8.0 on the Richter scale with more than 80 000 human lives lost and millions displaced. With inadequate shelter, poor access to health services, and disrupted ecology, the survivors were at enormous risk of infectious disease outbreaks. This work, believed to be unprecedented, was carried out to contain a possible outbreak through onsite monitoring of airborne biological agents in the high-risk areas. In such a mission, a mobile laboratory was developed using a customized vehicle along with state-of-art bioaerosol and molecular equipment and tools, and deployed to Sichuan 11 days after the earthquake. Using a high volume bioaerosol sampler (RCS High Flow) and Button Inhalable Aerosol Sampler equipped with gelatin filters, a total of 55 air samples, among which are 28 filter samples, were collected from rubble, medical centers, and camps of refugees, troops and rescue workers between 23 May and 9 June, 2008. After pre-treatment of the air samples, quantitative polymerase chain reaction (qPCR), gel electrophoresis, limulus amebocyte lysate (LAL) assay and enzyme-linked immunosorbent assay (ELISA) were applied to detect infectious agents and to quantify environmental toxins and allergens. The results revealed that, while high levels of endotoxin (180 similar to 975 ng/m(3)) and (1,3)-beta-D-glucans (11 similar to 100 ng/m(3)) were observed, infectious agents such as Bacillus anthracis, Bordetella pertussis, Neisseria meningitidis, Mycobacterium tuberculosis, influenza A virus, bird flu virus (H5N1), enteric viruses, and Meningococcal meningitis were found below their detection limits. The total bacterial concentrations were found to range from 250 to 2.5 x 10(5) DNA copies/L. Aspergillus fumigatus (Asp f 1) and dust mite allergens (Der p 1 and Der f 1) were also found below their detection limits.

BACKGROUND: A previous study from our laboratory showed that polybrominated diphenyl ethers (PBDEs) were metabolized to hydroxylated PBDEs (HO-PBDEs) in mice and that para-HO-PBDEs were the most abundant and, potentially, the most toxic metabolites. OBJECTIVE: The goal of this study was to determine the concentrations of HO-PBDEs in blood from pregnant women, who had not been intentionally or occupationally exposed to these flame retardants, and from their newborn babies. METHODS: Twenty human blood samples were obtained from a hospital in Indianapolis, Indiana, and analyzed for both PBDEs and HO-PBDEs using electron-capture negative-ionization gas chromatographic mass spectrometry. RESULTS: The metabolite pattern of HO-PBDEs in human blood was quite different from that found in mice; 5-HO-BDE-47 and 6-HO-BDE-47 were the most abundant metabolites of BDE-47, and 5'-HO-BDE-99 and 6'-HO-BDE-99 were the most abundant metabolites of BDE-99. The relative concentrations between precursor and corresponding metabolites indicated that BDE-99 was more likely to be metabolized than BDE-47 and BDE-100. In addition, three bromophenols were also detected as products of the cleavage of the diphenyl ether bond. The ratio of total hydroxylated metabolites relative to their PBDE precursors ranged from 0.10 to 2.8, indicating that hydroxylated metabolites of PBDEs were accumulated in human blood. CONCLUSIONS: The quite different PBDE metabolite pattern observed in humans versus mice indicates that different enzymes might be involved in the metabolic process. Although the levels of HO-PBDE metabolites found in human blood were low, these metabolites seemed to be accumulating.

Previous work has shown that certain parts of the Great Lakes region are polluted with Dechlorane Plus (DP), a highly chlorinated flame retardant that was used as a replacement for Dechlorane/Mirex. It was suspected that a source of DP to the environment might be its manufacturing facility located in the city of Niagara Falls, New York. To confirm this source location and to determine DP's spatial distribution, 26 tree bark samples were collected in triplicate from the northeastern United States, and the concentrations of DP and several brominated flame retardants (BFRs) were measured. Most concentrations of DP in tree bark were found to be much higher than those of the BFRs. The highest DP concentrations were > 100 ng g(-1) bark in the city of Niagara Falls, dropping rapidly width distance from the potential source. A simple one-dimensional, Gaussian diffusion model was used to explain the spatial distribution of DP and to locate the source. The calculated source location was < 7 km away from the DP manufacturing plant it! Niagara Falls, New York.

Previous research in the Taihu Lake Region (TLR) of China found high levels of atmospheric organochlorine pesticides (OCPs). To understand the sources and the environmental behaviors of these OCPs in the TLR, research on air-water gas exchange was performed in 2004. Hexachlorocyclohexanes (HCHs), DDT related compounds (DDTs), cis-chlordane (CC), trans-chlordane (TC), heptachlor (HEPT), and alpha-endosulfan in both air and water samples were analyzed, and air-water gas exchange fluxes of these compounds were calculated. The net volatilization flux of alpha-HCH was 58 ng m(-2) day(-1), suggesting that the residue of technical HCH in the lake sediment might have been an important source of alpha-HCH to the air of this region after the ban of technical HCH two decades ago. The main components of technical chlordane, TC, CC, and HEPT, each had net volatilization fluxes > 230 ng m(-2) day(-1), suggesting that waste discharge from manufacturing plants in the upper region was the main source of chlordane to the lake. Unlike alpha-HCH and chlordane, o,p'-DDT and alpha-endosulfan had net deposition fluxes, suggesting that these compounds were transported through the atmosphere from land sources and then deposited into the lake. The correlation between air concentrations and ambient air temperature indicated that the current sources of o,p'-DDT and alpha-endosulfan were from land; alpha-HCH and chlordane were mainly from the lake.

Our previous research on atmospheric samples suggested that Lake Ontario might receive significant amounts of Dechlorane Plus (DP), a highly chlorinated flame retardant, from the atmosphere and from inputs from DP's manufacturing facility in Niagara Falls, New York. To confirm this suspicion, a sediment core from the central basin of Lake Ontario was analyzed for the two isomers of DP, for polybrominated diphenyl ethers (PBDEs), and for 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE). The results showed that the concentration of DP in sediment increased rapidly starting in the mid-1970s and reached its peak concentration (310 ng g(-1) dry weight) in the mid-1990s. The peak flux and total inventory of DP were estimated to be 9.3 ng cm(-2) yr(-1) and 120 ng cm(-2), respectively. These values suggest that the total burden of DP in Lake Ontario is similar to 20 tons and that the maximum load rate was similar to 2 tons per year. The highest concentrations of PBDEs and TBE were found in the surficial sediment, with average concentrations of 2.8, 14, and 6.7 ng g(-1) d.w. for PBDE3-7 (tri- through hepta-BDEs), BDE-209, and TBE, respectively. The surface fluxes were 0.08, 0.43, and 0.20 ng cm(-2) yr(-1), and the inventories were 0.87, 3.9, and 1.8 ng cm(-2) for PBDE3-7, BDE-209, and TBE, respectively. The concentration of DP in Lake Ontario sediment exceeds that of the brominated flame retardants combined.

BACKGROUND: Previous studies have shown that polybrominated diphenyl ethers (PBDEs) behave as weak estrogens in animal and cell culture bioassays. In vivo metabolites of PBDEs are suspected to cause these effects. OBJECTIVES: To identify candidate metabolites, mouse plasma samples were collected after continuous oral and subcutaneous exposure to DE-71, a widely used commercial pentabromodiphenyl ether product, for 34 days. METHODS: Samples were extracted, separated into neutral and phenolic fractions, and analyzed by gas chromatographic mass spectrometry. RESULTS: In the plasma samples of orally treated animals, 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153) represented 52% of total measurable PBDEs, whereas it represented only 4.3% in the DE-71 mixture. This suggested that BDE-153 was more persistent than other congeners in mice. Several metabolites were detected and quantitated: 2,4-dibromophenol, 2,4,5-tribromophenol, and six hydroxylated PBDEs. The presence of the two phenols suggested cleavage of the ether bond of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodipheny ether (BDE-99), respectively. The hydroxylated (HO)-PBDEs might come from hydroxylation or debromination/hydroxylation. Among the quantitated hydroxylated metabolites, the most abundant was 4-HO-2,2',3,4'-tetra-BDE, which suggested that there was a bromine shift during the hydroxylation process. para-HO-PBDEs have been proposed to behave as endocrine disruptors. CONCLUSIONS: There seem to be three metabolic pathways: cleavage of the diphenyl ether bond, hydroxylation, and debromination/hydroxylation. The cleavage of the diphenyl ether bond formed bromophenols, and the other two pathways formed hydroxylated PBDEs, of which,para-HO-PBDEs are most likely formed from BDE-47. These metabolites may be the most thyroxine-like and/or estrogen-like congeners among the HO-PBDEs.

Studies showed that DDT levels were still high in Tianjin, China, even though its use was banned in 1983. To estimate current risk of DDT to human health in Tianjin area, a non-steady-state (Level IV) multimedia fugacity model was used to simulate the fate and transfer of pp'-DDT before and after the ban. The ordinary linear equations of Level IV model were solved with a matrix approach. The calculated pp'-DDT concentration in air, water, soil, and sediment reached a maximum in the 1980s and then decreased, and agree well with those measured. The biggest bulk sinks of pp'-DDT were soil and sediment, which accounted for 90% of total amount of pp'-DDT in the environment. Air deposition and diffusions through the interfaces of water-air and water sediment were the major intermedia transfer processes, while the degradation in soil and sediment were the key eliminating routes for pp'-DDT in the environment. (c) 2005 Elsevier Inc. All rights reserved.

High DDT concentrations and o,p'-DDT/p,p-DDT ratios observed in the air over Taihu Lake, a lake near Shanghai, China, led us to suggest that current use of dicofol in the area north of the lake was the main source of the measured DDTs. To examine this hypothesis, samples of commercially available formulated dicofol in China were collected in 2003 to measure the impurities of DDT related compounds (DOTS). The o,p'-DDT/p,p'-DDT ratio in the samples was 7.0, close to the observed value in the air over Taihu Lake. Average contents of op'-DDT, pp'-Cl-DDT, op'-DDE, and p,p'-DDT in the samples were 114, 69, 44, and 17 g per kg dicofol, respectively. On the basis of a production and distribution survey, total input of DOTS to the environment from the dicofol use in China was estimated to be 8770 t between 1988 and 2002. "Dicofol type DDT pollution", defined as DDT pollution caused by dicofol use and characterized with high op'-DDT/pp'-DDT ratio, might be serious in China, especially in southern and eastern China. The conversion of pp'-Cl-DDT to pp DOE can lead to high pp'-DDE/p,p-DDT ratio and could mislead the evaluation of pp'-DDT resident time in the environment. Therefore, more studies on pp'-Cl-DDT in the environment are needed.

Organochlorine (OC) pesticides have been used broadly in China's past, yet very little is known about their atmospheric concentrations and transport. In this work, air samples were collected in the Taihu Lake Region, China, from July 23 to August 11, 2002, to measure concentrations of OC pesticides in air. The average concentrations of alpha and gamma-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), heptachlor (HEPT), alpha-endosulfan, p,p'-DDT, p,p'-DDE, p,p'-DDD, and o,p'-DDT in the air were 74 and 46, 47, 53, 307, 124, 212, 36, and 767 pg m(-3), respectively. It was interesting to note that the concentrations of p,p'-DDT, p,p'-DDE, and o,p'-DDT were all very high, even though the use of technical DDT has been banned in China since 1983. Moreover, the average concentration ratios of o,p'-DDT/p,p'-DDT and p,p'-DDE/p,p'-DDT were as high as 6.3 and 1.8. This-suggested that there could be an unknown source of DDT-related compounds (DDTs), especially o,p'-DDT and p,p'-DDE. It is very likely that this unknown source was the application of dicofol, an acaricide manufactured from technical DDT and used mainly on cotton fields to treat mites in China. Backward trajectory analysis also provided consistent evidence that the high air concentrations of DDTs were related to trajectories from the area north of the Yangtze River, where cotton fields account for a significant fraction of land use.