Recent survey and effects of cooking processes on levels of PCDDs,PCDFs and Co-PCBs in leafy vegetables in Japan

We report here the latest levels of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and coplanar polychlorinated biphenyls (Co-PCBs) in leafy vegetables in Japan as well as the effect of cooking processes on the reduction of these contaminants. Three kinds of leafy vegetables (“komatsuna”, lettuce and spinach) from seven districts in Japan in 1998 were analyzed for the 2,3,7,8-chlorine substituted PCDD/Fs and three non-ortho-PCBs (#77, 126 and 169). The mean total TEQ levels (using the WHO-TEFs) in the komatsuna, lettuce and spinach were 0.094, 0.025 and 0.196 pg/g fresh weight, respectively. The TEQ levels are dominated by 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3^′,4,4^′,5-PeCB in many of the samples. For one of these isomers, the 2,3,4,7,8-PeCDF TEQ levels showed good correlation with the total TEQ levels in the samples (r=0.957). This suggests that 2,3,4,7,8-PeCDF may be an indicator for dioxin contamination in the analysis of the leafy vegetables. Also, the effects of two cooking processes (washing and washing followed by boiling) on the dioxin levels in two types of spinach samples were investigated. On average, in both samples, the total concentrations of the PCDDs, PCDFs and Co-PCB were reduced to about 38%, 73% and 88% of the initial concentrations by washing, and to 21%, 35% and 61% of the initial concentrations by washing followed by boiling. The total TEQ levels were reduced to about 30% of the initial TEQ levels by washing followed by boiling. Significant reductions in the TEQ levels were observed in the cooked samples. Thus, the cooking processes may reduce the risk of dioxin intake from the leafy vegetables.     

Levels and patterns of polychlorinated biphenyls in residues from incineration of established source-classified MSW in China

Municipal solid waste (MSW) source-classified collection represents an advancement in resource cycling and secondary pollution control in China. Comparative experiments were performed to assess the levels and patterns of polychlorinated biphenyls in bottom ash, fly ash from boiler, and fly ash from bag filter from an MSW incineration plant with source-classified collection of MSW. Polychlorinated biphenyls were concentrated in the bag filter fly ash and in the bottom ash. The total amount of polychlorinated biphenyls was much lower than in fly ashes and bottom ash from traditional mixed waste incineration. Total concentration of coplanar polychlorinated biphenyls and toxic equivalent quantities were also reduced. Due to variations of feed waste, complete combustion, including continuously high incineration temperature, low CO concentrations and high air excess ratio were observed. Incineration temperature showed a negative correlation, while CO concentration showed a positive correlation with total and coplanar polychlorinated biphenyls, indicating that the latter can be reduced by controlling combustion conditions related to properties of feed waste.     

电子废物拆解区农业土壤中PCNs的污染水平、分布特征与来源解析

用GC-NCI-MS法测定了路桥农业表层土壤中46种多氯萘(PCNs)的含量.目的是了解该地区表层土壤中PCNs的污染水平、空间分布特征和来源.结果表明,所有表层土壤样品中ΣPCNs的含量为0.062～2.92 ng.g-1,平均值为0.630 ng.g-1.多数样品中tetra-CNs和penta-CNs是最主要的同族体,分别占18.4%～88.8%(平均值为46.7%)和8.40%～53.1%(平均值为30.7%),其次是tri-CNs,范围为0～47.3%,平均值为10.6%.聚类分析和燃烧指示物分析表明,采样点主要受Halowax1014和Halowax 1013工业品污染,PCBs工业品和电子废物燃烧也可能对污染有贡献.与国内外其它研究相比,研究区域内土壤中PCNs污染处于中等水平.     

现代黄河三角洲土壤中多氯联苯来源解析研究

对现代黄河三角洲22个表层土壤样品中类二英类多氯联苯（PCBs）进行双毛细管柱GC-ECD结合MS测试,并对所得数据进行主成分分析,在同系物水平上解析了现代黄河三角洲土壤中PCBs污染的类型、来源、贡献率和同系物组成.结果表明,现代黄河三角洲土壤中PCBs污染存在4类污染源：第1类污染是由地表径流带来的非点源污染,来自黄河沿岸企业的工业生产和使用,其贡献率为49.6％,同系物组成与国产PCBs相似,且与Aroclor1221相对应;第2和第3类同属点源污染,来自沿海地区的油田开采活动,贡献率分别为15.0％和10.1％,第2类同系物组成与Aroclor1221和Aroclor1242叠加的结果类似,第3类与Aroclor1260相似;第4类污染是由大气污染导致的非点源污染,来自大气的干、湿沉降,其贡献率为8.4％,同系物组成与Aroclor1242、Aroclor1248和Aroclor1260叠加的结果类似.     

Occurrence and congeners specific of polychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% of ∑PCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% of ∑PCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.     

土壤中多氯联苯分析方法研究进展

文中综述了多氯联苯的分析技术及其研究进展。介绍了样品前处理技术如索氏萃取法、超声萃取法、微波辅助萃取、超临界流体萃取、加速溶剂萃取等在土壤样品中多氯联苯分析中的应用;阐述了气相色谱、液相色谱、气质联用技术在土壤样品中多氯联苯的检测,并对土壤中未来多氯联苯检测技术的发展提出了展望。     

A national survey of polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in Chinese mothers' milk

Seven polybrominated diphenyl ethers (PBDEs) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) congeners (CB-28, CB-52, CB-101, CB-138, CB-153 and CB-180) were measured in 24 pooled human milk samples comprised of 1237 individual samples from 12 provinces in China. The samples were taken to estimate the background body burden of general population and assess nursing infant exposure via human milk in China. The median concentrations of ∑₇PBDEs and ∑₆PCBs were 1.49 and 10.50 ng g⁻¹ lipid weight (lw), respectively. BDE-28, BDE-47 and BDE-153 were predominant PBDE congeners accounting for nearly 70% of ∑₇PBDEs. As for indicator PCBs, CB-153 was the most abundant congener, followed by CB-138. In our study, there was no significantly statistical relationship between concentrations of PBDEs in milk samples and maternal age as well as dietary habits. ∑₇PBDEs did not correlate to ∑₆PCBs in Chinese mothers’ milk. The human exposure to indicator PCBs in China was found to be significantly determined by maternal age, dietary habits and geographical factors. It is suggested that Chinese general population is probably exposed to PBDEs with multiple sources and pathways. The estimated daily intakes (EDI) of BDE-47, BDE-99 and BDE-153 for the Chinese nursing infant were much lower than corresponding threshold reference values suggested by USEPA.     

Volatile organic compounds at swine facilities: A critical review

Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions.Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples.The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts.Identification and quantification of VOCs were restricted by using instruments based on gas Chromatography (GC) and liquid chromatography (LC) with different detectors most of which require time-consuming procedures to obtain results. Various methodologies and technologies in sampling, sample preparation, and sample analysis have been used. Only four publications reported using GC based analyzers and PTR-MS (proton-transfer-reaction mass spectrometry) that allowed continuous VOC measurement. Because of this, the majority of experimental studies were only performed on limited numbers of air, manure, or dust samples. Many aerial VOCs had concentrations that were too low to be identified by the GC peaks.Although VOCs emitted from swine facilities have environmental concerns, only a few studies investigated VOC emission rates, which ranged from 3.0 to 176.5 mg d⁻¹ kg⁻¹ pig at swine finishing barns and from 2.3 to 45.2 g d⁻¹ m⁻² at manure storages. Similar to the other pollutants, spatial and temporal variations of aerial VOC concentrations and emissions existed and were significantly affected by manure management systems, barn structural designs, and ventilation rates.Scientific research in this area has been mainly driven by odor nuisance, instead of environment or health concerns. Compared with other aerial pollutants in animal agriculture, the current scientific knowledge about VOCs at swine facilities is still very limited and far from sufficient to develop reliable emission factors.     

Residues of organochlorine pesticides and PCBs in some Brazilian municipal solid waste compost

Persistent organic pollutants (POPs), organochlorine pesticides and polychlorinated biphenyls (PCBs), listed as per the Stockholm Convention (α -HCH, β -HCH, γ -HCH, p,p′-DDT, o,p′-DDT, p,p′-DDD, p,p′-DDE, aldrin, endrin, dieldrin, PCBs 28, 52, 118, 138, 153, and 180), were analyzed in municipal solid waste (MSW) compost samples from three different Brazilian composting plants located in three São Paulo State cities: Araras, Araraquara and São Paulo (Vila Leopoldinha). Quantitative and qualitative analyses were carried out using gas chromatography electron capture detection (GC-ECD) and gas chromatography mass spectrometry (GC-MS) (Ion Trap, electron impact ionization), respectively. The samples were analyzed in triplicate and the target POPs were not detected by GC-ECD. Twelve pollutants were identified in two samples when qualitative analysis (GC-MS) was used (β -HCH, γ -HCH, p,p′-DDT, o,p′-DDT, p,p′-DDD, and p,p′-DDE, PCBs 28, 118, 138, 153 and 180). The composting process has advantages such as urban solid waste reduction and landfill life-span increase, however the MSW compost quality, which can be utilized for agricultural purposes, should be evaluated and be controlled. This kind of study is the first step in making available information to answer questions regarding MSW compost for sustainable agricultural use, such as the pollutants accumulation in soil and in groundwater, and plants uptake.     

Linking empirical estimates of body burden of environmental chemicals and wellness using NHANES data

Biomonitoring of industrial chemicals in human tissues and fluids has shown that all people carry a “body burden” of synthetic chemicals. Although measurement of an environmental chemical in a person's tissues/fluids is an indication of exposure, it does not necessarily mean the exposure concentration is sufficient to cause an adverse effect. Since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) associated with low-level exposures to multiple classes of contaminants, which may impact a variety of organ systems. The objective of this research is to link measures of body burden of environmental chemicals and a “holistic” measure of wellness. The approach is demonstrated using biomonitoring data from the National Health and Nutrition Examination Surveys (NHANES). Forty-two chemicals were selected for analysis based on their detection levels. Six biological pathway-specific indices were evaluated using groups of chemicals associated with each pathway. Five of the six pathways were negatively associated with wellness. Three non-zero interaction terms were detected which may provide empirical evidence of crosstalk across pathways. The approach identified five of the 42 chemicals from a variety of classes (metals, pesticides, furans, polycyclic aromatic hydrocarbons) as accounting for 71% of the weight linking body burden to wellness. Significant interactions were detected indicating the effect of smoking is exacerbated by body burden of environmental chemicals. Use of a holistic index on both sides of the exposure-health equation is a novel and promising empirical “systems biology” approach to risk evaluation of complex environmental exposures.