杭州市典型农业和工业区氯代POPs的残留、土气交换特征及健康风险研究

发布时间：2018-04-06 07:27

本文选题：有机氯农药　切入点：多氯联苯　出处：《浙江大学》2017年硕士论文

【摘要】：持久性有机污染物(Persistent organic pollutants,POPs)能够持久存在于环境中,并且能够随着食物链在动物和人体内不断积蓄,具有半挥发性和高毒性,目前受到全球范围的广泛关注。典型的氯代持久性有机物包括有机氯农药六六六(Hexachlorocyclohexanes,HCHs)、滴滴涕(Dichlorodiphenyltrichloroethanes,DDTs)和多氯联苯(Polychlorinated biphenyls,PCBs),虽然已被禁用几十年,但由于它们在我国的历史产量和使用量十分巨大,至今仍能在各种环境介质中检出,并且持续地对生态系统和人体健康造成危害。因此,研究这类物质在环境中的残留、归趋等行为以及评价其对人体的健康风险是十分必要的。在本论文的研究中,我们采集了杭州市典型农业和工业区的土壤和大气样品,分析了其中HCHs、DDTs和PCBs的浓度,并针对具有手性的有机氯农药α-HCH、o,p'-DDD和o,p'-DDT进行了对映体分析,利用异构体和对映体选择性残留特征阐述了它们的来源及土气交换行为,解释了其在空间和季节上的差异,最后利用美国EPA健康风险评价模型对土壤和大气中的此类物质进行了暴露风险评估。本文得到的主要结果如下:(1)研究区域土壤中冬季∑HCHs的浓度大于夏季浓度,农业区浓度大于工业区浓度,具体浓度水平为:冬季农业区0.224-3.71(均值1.47)ng/g,冬季工业区0.228-1.61(均值0.555)ng/g,夏季农业区0.023-2.36(均值0.615)ng/g,夏季工业区0.037-1.58(均值0.301)ng/g;其中β-HCH在大部分土壤样品中占主导地位。与土壤中浓度时空特征相反,大气中夏季∑HCHs浓度大于冬季浓度,工业区浓度大于农业区浓度,具体浓度水平为:冬季农业区20.1-42.0(均值27.9)pg/m~3,冬季工业区26.8-77.1(均值42.7)pg/m~3,夏季农业区32.4-73.0(均值40.8)pg/m~3,夏季工业区9.04-62.2(均值45.6)pg/m~3;其中α-HCH在大部分大气样品中占主导地位。来源分析结果表明,研究区域土壤和大气中HCHs的残留主要来源于历史上工业六六六的使用。对于手性α-HCH,大部分土壤中(-)-α-HCH会优先降解,而大气中冬季(+)-α-HCH优先降解,夏季则(-)-α-HCH优先降解。逸度分数表明,目前研究区域HCHs处于从土壤向大气挥发的状态,土壤仍是大气中HCHs的二次来源,且冬季的农业区HCHs挥发趋势较强。对土壤和大气中HCHs通过多种途後暴露于人体产生的健康风险进行评估,HCHs对人体不具有非致癌风险,致癌风险也非常低。(2)研究区域土壤中冬季∑DDTs的浓度大于夏季浓度,农业区浓度大于工业区浓度,具体浓度水平为:冬季农业区0.721-1594(均值96.5)ng/g,冬季工业区0.608-79.8(均值12.3)ng/g,夏季农业区0.312-938(均值67.5)ng/g,夏季工业区0.572-125(均值12.1)ng/g;其中p,p'-DDE和p,p'-DDT在大多数土壤样品中占主导地位。与土壤中浓度时空特征相反,大气中ΣDDTs的浓度夏季大于冬季,没有显著的空间差异性,具体浓度水平为:冬季农业区37.1-363(均值52.1)pg/m~3,冬季工业区48.5-141(均值42.5)pg/m~3,夏季农业区90.7-325(均值137)pg/m~3,夏季工业区33.5-401(均值162)pg/m~3;其中p,p'-DDE在大部分大气样品中占主导地位。来源分析结果表明,大多数土壤中DDTs的残留来源于历史上工业DDTs的使用,少部分土壤可能受到三氯杀螨醇或DDTs再次使用导致的新来源的影响;而大气中大部分样品可能受到三氯杀蹒醇等新来源的影响。对于手性o,p'-DDD和o,p'-DDT,所有土壤和大气样品中的o,p'-DDT和o,p'-DDD都是非外消旋的。对于o,p'-DDT,土壤和大气中都是(+)-对映体会优先降解;对于o,p'-DDD,土壤中(+)-对映体会优先降解,大气中则是(-)-对映体会优先降解。逸度分数表明,部分样品中DDTs处于挥发状态,部分样品中DDTs处于平衡状态,其余样品中DDTs处于沉降状态。且冬季的农业区DDTs的逸度分数较高。对土壤和大气中DDTs通过多种途径暴露于人体产生的健康风险进行评估,DDTs对人体不具有非致癌风险,致癌风险非常低。(3)研究区域土壤中∑PCBs的浓度不具有显著空间差异性,冬季浓度大于夏季浓度,具体浓度水平为:冬季农业区68.6-1828(均值524)pg/g,冬季工业区104-1838(均值404)pg/g,夏季农业区47.4-1327(均值323)pg/g,夏季工业区25.2-804(均值307)pg/g;在大多数土壤样品中5Cl-和6Cl-PCBs占主导地位。大气中∑PCBs的浓度不具有显著空间差异性,冬季浓度大于夏季浓度,具体浓度水平为:冬季农业区224-480(均值345)pg/m~3,冬季工业区233-537(均值326)pg/m~3,夏季农业区135-553(均值353)pg/m~3,夏季工业区39.6-253(均值133)pg/m~3;在大多数大气样品中7Cl-PCBs占主导地位。来源分析结果表明,土壤中的PCBs来源于工业品Aroclor1254,而大气可能受到多种工业品Aroclor的混合污染。逸度分数表明,大部分懫样点PCBs处于平衡状态或从大气向土壤沉降,其逸度分数的大小与PCBs的分子量大小有关。冬季的逸度分数高于夏季,空间变化特征与PCBs的分子量大小有关。健康风险评价表明,个别土壤样品中PCBs对儿童表现出了非致癌风险,其余大部分土壤和大气样品中PCBs对人体不具有非致癌风险。一部分土壤和大气样品中PCBs会对人体产生低的致癌性风险,其余样品对人体产生非常低的致癌性风险。
[Abstract]:Persistent organic pollutants (Persistent organic, pollutants, POPs) can persist in the environment, and can with the food chain in the animal and human body time savings, with semi volatile and highly toxic, currently widespread concern worldwide. Typical chlorinated organic compounds including persistent organochlorine pesticides (Hexachlorocyclohexanes, HCHs 666 (Dichlorodiphenyltrichloroethanes, DDTs), DDT and polychlorinated biphenyls (Polychlorinated) biphenyls, PCBs), although has been disabled for decades, but because they are popular in China and the use of history is huge, can still be detected in various environmental media, and continuously to the ecosystem and human health hazard. Therefore, study on residue of such substances in the environment, and fate of behavior and evaluate the risk to human health is very necessary in the research of this thesis. , we collected soil and air samples in Hangzhou City, a typical agricultural and industrial areas, analyzes the HCHs, concentration of DDTs and PCBs, and the organochlorine pesticides with chiral alpha -HCH, O, p'-DDD and O, p'-DDT for the enantiomeric analysis, the isomers and enantiomers of residual features describes the sources and their rustic exchange behavior, explains its spatial and seasonal differences, finally using the EPA health risk assessment model of exposure risk assessment of such substances in soil and air. The main results are as follows: (1) concentration of regional soil in winter than in summer HCHs the concentration of agricultural area is greater than the concentration of industrial zone concentration, the specific concentration level: Winter agricultural area 0.224-3.71 (mean 1.47 ng/g), winter Industrial Zone 0.228-1.61 (mean 0.555) ng/g, the summer agricultural area 0.023-2.36 (mean 0.615 ng/g), summer industry 0.037-1.58 (mean 0.301) ng/g; the beta -HCH is dominant in most soil samples. In contrast with the concentration in the soil spatial characteristics, the concentration of HCHs in the atmosphere in winter than summer sigma concentration, industrial zone is greater than the concentration of agricultural area concentration, the specific concentration level: Winter agricultural area 20.1-42.0 (mean 27.9 pg/m~3), winter Industrial Zone 26.8-77.1 (mean 42.7 pg/m~3), the summer agricultural area 32.4-73.0 (mean 40.8 pg/m~3), summer Industrial Zone 9.04-62.2 (mean 45.6) pg/m~3; the alpha -HCH is dominant in most atmospheric samples. The results show that the use of HCHs in soil and air residue mainly comes from the history of the 666 industry. For most of the soil in the chiral -HCH (-) - alpha -HCH preferentially degraded, and the atmosphere in winter (+) - alpha -HCH preferentially degraded, summer (-) - alpha -HCH preferential degradation. The fugacity fraction showed that the study area HCH S from the soil to the atmosphere in the volatile state, the two sources of HCHs soil remains in the atmosphere, and the winter agricultural area. A strong tendency to volatilization of HCHs to evaluate the health risk of HCHs in soil and air through a variety of ways after exposure to the human body, HCHs on the human body does not have non carcinogenic risk, risk of cancer is very low. (2) concentration of regional soil in winter than that in summer the total DDTs concentration, agricultural area concentration is greater than the industrial area of concentration, the specific concentration level: Winter agricultural area 0.721-1594 (mean 96.5 ng/g), winter Industrial Zone 0.608-79.8 (mean 12.3) ng/g, the summer agricultural area 0.312-938 (mean 67.5 ng/g), summer Industrial Zone 0.572-125 (mean 12.1 ng/g); the P, p'-DDE and P, p'-DDT is dominant in most soil samples. In contrast with the concentration of space-time in soils, the concentration of atmospheric DDTs Sigma in summer than in winter, no significant spatial difference. The concentration level, winter agricultural area 37.1-363 (mean 52.1) pg/m~3, winter Industrial Zone 48.5-141 (mean 42.5 pg/m~3), the summer agricultural area 90.7-325 (mean 137 pg/m~3), summer Industrial Zone 33.5-401 (mean 162) pg/m~3; P, p'-DDE is dominant in most atmospheric samples. Analysis results show that the use of DDTs source, residues in most soils in the history of industrial DDTs, the impact of new sources of some soil may be three dicofol or DDTs used again due to the influence of the atmosphere; most of the samples may be a new source of such three kill mites. For the chlorine alcohol chiral o, p'-DDD and O, p'-DDT all, atmosphere and soil samples of O, p'-DDT and O, p'-DDD are non racemic. For O, p'-DDT, soil and atmosphere are (+) - enantiomer of preferential degradation; for O, p'-DDD, soil (+) - enantiomer of the atmosphere is the preferred degradation. (- ) - enantiomers experience first degradation. The fugacity fraction showed that some samples of DDTs in a volatile state, part of DDTs in the sample is in balance, the remaining samples in DDTs in the subsidence state. High and winter agricultural area DDTs fugacity fraction. To assess the health risk of DDTs in soil and air through a variety of ways of exposure in the human body, DDTs on the human body does not have non carcinogenic risk, risk of cancer is very low. (3) the study area soil total PCBs concentration has no significant spatial difference, concentration in winter than summer concentration, the specific concentration level: Winter agricultural area 68.6-1828 (mean 524 pg/g), 104-1838 (winter industrial zone the mean value of 404 pg/g), the summer agricultural area 47.4-1327 (mean 323) pg/g summer Industrial Zone 25.2-804 (mean 307 pg/g); 5Cl- in most soil samples and 6Cl-PCBs was dominant. The concentration of atmospheric PCBs has no significant spatial difference Specific concentration in winter than that in summer, the concentration, the specific concentration level: Winter agricultural area in 224-480 (mean 345) pg/m~3, winter Industrial Zone 233-537 (mean 326) pg/m~3, summer agricultural district 135-553 (mean 353) pg/m~3 summer Industrial Zone 39.6-253 (mean 133) pg/m~3; 7Cl-PCBs is dominant in most atmospheric samples. The analysis results showed that the soil PCBs from industrial Aroclor1254, and the atmosphere may be mixed pollution in a variety of industrial products of Aroclor. The fugacity fraction showed that most Zhi sample PCBs in equilibrium or from atmosphere to soil subsidence, the molecular size and the size of PCBs. The fugacity fraction of winter fugacity the molecular weight fraction is higher than that in summer, the spatial variation and PCBs. Health risk assessment indicated that individual soil samples for PCBs in children showed a non carcinogenic risk, most of the remaining soil and air samples PCBs has no non carcinogenic risk to human body. Part of PCBs in soil and air samples will cause low carcinogenic risk to human body, and the rest samples will have a very low carcinogenic risk to human body.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X592

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