Heavy metals in rice and garden vegetables and their potential health risks to inhabitants in the vicinity of an industrial zone in Jiangsu, China

Contamination of soil and agricultural products by heavy metals resulting from rapid industrial development has caused major concern. In this study, we investigated heavy metal (Cu, Zn, Pb, Cr, Hg and Cd) concentrations in rice and garden vegetables, as well as in cultivated soils, in a rural-industrial developed region in southern Jiangsu, China, and estimated the potential health risks of metals to the inhabitants via consumption of locally produced rice and garden vegetables. A questionnaire-based survey on dietary consumption rates of foodstuffs showed that rice and vegetables accounted for 64% of total foodstuffs consumed, and over 60% of rice and vegetables were grown in the local region. Average concentrations of Cr, Cu, Zn, Cd, Hg and Pb were 0.75, 2.64, 12.00, 0.014, 0.006 and 0.054 mg/kg dw (dry weight) in rice and were 0.67, 1.18, 4.34, 0.011, 0.002 and 0.058 mg/kg fw (fresh weight) in garden vegetables, respectively. These values were all below the maximum allowable concentration in food in China except for Cr in vegetables. Leafy vegetables had higher metal concentrations than solanaceae vegetables. Average daily intake of Cr, Cu, Zn, Cd, Hg and Pb through the consumption of rice and garden vegetables were 5.66, 16.90, 74.21, 0.10, 0.04 and 0.43 μg/(kg·day), respectively. Although Hazard Quotient values of individual metals were all lower than 1, when all six metal intakes via self-planted rice and garden vegetables were combined, the Hazard Index value was close to 1. Potential health risks from exposure to heavy metals in self-planted rice and garden vegetables need more attention.     

Environmental assessment of organic soybean (Glycine max.) imported from China to Denmark: a case study

Growing global trade with organic products has increased the demand for environmental impact assessments during both production and transport. Environmental hotspots of organic soybeans produced in China and imported to Denmark were identified in a case study using a life cycle assessment approach. Furthermore, environmental impacts of organic and conventional soybeans at farm gate were compared in the case study. The total global warming potential (GWP) per ton organic soybeans imported to Denmark revealed that 51% came from transportation and 35% from the farm level. Comparing organic and conventional soybean at farm gate showed that GWP, non-renewable energy use, acidification and eutrophication was lower per ton organic soybeans, whereas land use was slightly higher.     

阿特拉津在土壤中的降解途径及其对持留性的影响

通过田间和实验室试验，研究了除草剂阿特拉津在土壤中的降解代谢规律及其与土壤特性的关系。试验表明，阿特拉津施用后、在作物生长期内可降解９０％以上，土壤酸碱度对阿特拉津在土壤中的代谢有显著影响。在碱性土壤中阿特拉津主要经过微生物代谢而被降解；在酸性土壤中化学水解占优势地位。阿特拉津在强酸性土壤中的持留性（半衰期为６３ｄ）低于弱酸性土壤中的持留性（半衰期为８４ｄ），而在碱性土壤中由于较强的微生物降解作用，其持留性（半衰期为５１ｄ）最低。     

Identifying factors that influence soil heavy metals by using categorical regression analysis: A case study in Beijing,China

A method was proposed to identify the main influence factors of soil heavy metals. The influence degree of different environmental factors was ranked. Parent material, soil type, land use and industrial activity were main factors. Interactions between some factors obviously affected soil heavy metal distribution. Identifying the factors that influence the heavy metal contents of soil could reveal the sources of soil heavy metal pollution. In this study, a categorical regression was used to identify the factors that influence soil heavy metals. First, environmental factors were associated with soil heavy metal data, and then, the degree of influence of different factors on the soil heavy metal contents in Beijing was analyzed using a categorical regression. The results showed that the soil parent material, soil type, land use type, and industrial activity were the main influencing factors, which suggested that these four factors were important sources of soil heavy metals in Beijing. In addition, population density had a certain influence on the soil Pb and Zn contents. The distribution of soil As, Cd, Pb, and Zn was markedly influenced by interactions, such as traffic activity and land use type, industrial activity and population density. The spatial distribution of soil heavy metal hotspots corresponded well with the influencing factors, such as industrial activity, population density, and soil parent material. In this study, the main factors affecting soil heavy metals were identified, and the degree of their influence was ranked. A categorical regression represents a suitable method for identifying the factors that influence soil heavy metal contents and could be used to study the genetic process of regional soil heavy metal pollution.     

上海港区船舶防污漆中Irgarol 1051的环境风险评价

Irgarol 1051是一种常用于船舶防污漆的杀生活性物质。为了评价船舶防污漆杀生活性物质Irgarol 1051的海洋环境风险,根据ISO 13073-1的评价原则和程序,对其进行环境危害评价、环境暴露评价和风险表征。通过对公共数据库的文献检索获取数据,从理化性质、环境行为、生态毒性3个方面评价Irgarol 1051的环境危害。采用评估因子法计算Irgarol 1051的预测无效应浓度(PNEC)。采用质量守恒法计算Irgarol 1051在海水中的释放率,通过MAMPEC v3.0模型推导上海洋山深水港的集装箱船区、码头、航道等暴露场景的预测环境浓度(PEC)。经过比较上述暴露场景的风险商值(PEC/PNEC)发现,港口的海水相风险商值大于1,Irgarol 1051的环境风险需要关注。     

Parametric approach of the domino effect for structural fragments

More specific and accurate probabilistic models of the numbers of fragments generated respectively by Boiling Liquid Expanding Vapor Explosions (BLEVEs), Mechanical Explosions (MEs), Confined Explosions (CEs), and Runaway Reactions (RRs) of a horizontal cylindrical vessel were developed using the maximum entropy principle based on historical accident data. The theoretical results from the four probability density functions were compared to the observed data, and the numbers of fragments followed discrete exponential distributions in the interval [1, 9]. Beside the summary of the probabilistic distributions of the other random variables in the process of fragment projection, the effects on the fragment trajectory and target terms were investigated using a parametric approach. The results showed that using the complete model, wind shear, turbulence, and absence of fragment rotation caused the fragments to impact within shorter distances; fragment rotation and lack of wind decreased the probability of impact within a given distance, but the rupture probability of the target was not affected by fragment rotation or wind. The probabilistic confidence intervals of fragment range, impact, and target penetration became narrower with the number of simulation runs, but the accuracy of the results increased. The probability of fragment impact increased with the volume of the target vessel and the degree of filling of the explosion vessel, but did not depend on the kind of explosion. The probability of target rupture increased slowly with the degree of filling of the explosion vessel, but was little influenced by the volume of the target vessel or the kind of explosion.     

五氯酚对土壤跳虫代谢转化酶基因和蜕皮相关基因表达的影响

五氯酚(PCP)是一种广泛存在于环境中的有机污染物。利用土壤跳虫(Folsomia candida)作为受试生物,研究了不同浓度的PCP暴露下细胞色素P450(CYP450)基因、谷胱甘肽转移酶(GST)基因和蜕皮相关基因表达水平的变化。结果显示,PCP暴露下,跳虫CYP450基因Fcc01651、Fcc02155、Fcc03650和GST基因Fcc04073、Fcc05260的表达水平未发生显著变化。在PCP浓度为240 mg·kg-1时,跳虫GST基因Fcc00494的表达显著上调。在PCP浓度为120 mg·kg-1和240 mg·kg-1时,几丁质酶基因Fcc00881和几丁质结合域基因Fcc01306的表达受到显著抑制。研究结果可为评价PCP暴露对跳虫的毒性提供一定依据。     

室内环境中持久性卤代有机污染物的人体暴露及潜在生殖健康影响

卤代持久性有机污染物(Hal-POPs),如多溴联苯醚(PBDEs)、多氯联苯(PCBs)、滴滴涕(DDT)等是环境中广泛存在的全球性有机污染物,同时它们又是内分泌干扰物,是威胁人类生殖健康的重要因素之一。由于人们每天约有80%以上的时间在室内度过,且室内环境是Hal-POPs人体暴露的主要来源之一,因此室内环境中Hal-POPs对人体内分泌系统的干扰作用及其机理等问题亟待研究,但目前这方面的研究很有限。本文通过综述Hal-POPs在室内环境中的赋存水平和在人体体内的负荷水平及其半衰期,探讨了其对人体内分泌系统尤其是男性生殖健康的影响情况及其可能的机理,并分析了目前研究的不足之处及研究前景,为进一步开展这方面的研究提供借鉴。     

Dechlorination of 2,2＇,4,4＇,5,5＇-hexachlorobiphenyl by thermal reaction with activated carbon-supported copper or zinc

Activated carbon （AC）-supported copper or zinc made from ion exchange resin （IRCu-C and IRZn-C） have an increased metal load of 557.3 mg·g^-1 and 502.8 mg·g^-1 compared to those prepared by the traditional method involving impregnation with AC and copper （II） citrate or zinc citrate solution （LaCu-C and LaZn-C） of 12.9 mg·g^-1 and 46.0 mg·g^-1 respectively. When applied to decompose 2,2＇,4,4＇,5,5＇-hexachlorobiphenyl at 250 ℃, IRCu-C achieved higher activity of 99.0% decomposition efficiency than LaCu-C of 84.7%, IRZn-C of 90.5% and LaZn-C of 62.7%. When the reaction temperature rose to 350 ℃, all the four kinds of reactants can decompose PCB- 153 with efficiency above 90%. Further, X-ray photoelec- tron spectroscopy characterization of IRCu-C before and after the reaction indicated transformation of 19.1% of Cu atoms into Cu^2＋, illustrating that Cu is the active ingredient or electron donor promoting the decomposition of PCB- 153. The mechanism underlying this process differs from a traditional H donor. However, there is no significant change on the surface of IRZn-C before and after the reaction, suggesting that Zn acts as catalyst during the process of PCB-153 decomposition.     

钼矿区选矿场周边农田土壤重金属污染状况分析与评价

以葫芦岛市钼矿区为例,分析钼矿区选矿场周边农田土壤重金属污染状况并对其污染现况进行评价.选择选矿场周边受污染农田土壤样本20个,采用HNO3-HF-HClO4混酸对土壤样品进行处理,运用等离子体发射光谱仪(ICP-AES)测定土壤样品中Mo、Pb、As、Hg、Cr、Cd、Zn、Cu、Ni的全量并进行评价.结果表明:钼矿区选矿厂周边农田土壤重金属Nemerow综合指数8.46,综合评价结果为该区土壤已受严重污染;主要污染物为Cd、Cr、Hg、Zn,并伴有Ni、Cu污染;选矿厂周边农田土壤重金属元素全量中化学形态分布为:残余态＞有机结合态＞氧化结合态＞酸可提取态;农田酸可提取态、氧化结合态、有机结合态三种形态的重金属可能来源于不同外援污染;重金属Hg的有效态比例较大,可能会影响农作物的正常生长;钼矿区选矿区周边农田土壤重金属污染除来源于污染地下水的浇灌,还来源于大气降尘、汽车尾气以及矿物运输过程中矿石的遗落.