滨海湿地土壤典型有机污染物生态效应及健康风险研究

发布时间：2018-01-29 08:23

本文关键词： 滨海湿地生态效应土壤酶活性土壤微生物健康风险评价蒙特卡罗模拟　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,随着工业化和城镇化的迅速发展,人类向环境排放了大量的污染物,使滨海湿地受到了空前的环境压力。一些持久性有机污染物由于其难降解的特性,易在湿地环境中不断累积,对生态环境和人体健康产生潜在危害。因此,进一步研究有机污染物在湿地环境中的生态效应和健康风险对保护生态环境和人体健康具有重要意义。本研究以滨海湿地环境中普遍存在的持久性有机污染物多环芳烃(Polycyclic Aromatic Hydrocarbons, PAHs)和五氯酚(Pentachlorophenol, PCP)为研究对象,探讨了PCP、菲和芘对滨海湿地土壤中土壤微生物(细菌、真菌、放线菌)数量和土壤酶(脲酶和蔗糖酶)活性的影响。选取我国两大滨海湿地(辽河口湿地和胶州湾湿地)为研究对象,计算了滨海湿地土壤中PAHs和PCP经由直接摄入、皮肤接触和呼吸摄入三类暴露途径的致癌风险。在进行致癌风险评价时,分别应用了两种致癌风险评价模型(ILCR模型和RAGS模型)计算致癌风险,并比较了两种模型之间的差异。为了提高评价结果的准确性,在健康风险评价过程中我们成功将概率风险评价方法(蒙特卡罗模拟)用于健康风险评价,并确定了对评价结果准确性影响最大的关键参数,为提高评价结果的准确性提供依据。本研究结果表明：(1)土壤中PCP的存在会对土壤细菌产生促进效应,对土壤真菌在浓度低于100x103ng/g时促进,在浓度为150x103ng/g时抑制,而对土壤放线菌则产生抑制效应。土壤中菲的存在会对土壤细菌产生抑制效应,而对土壤真菌在浓度低于300ng/g时促进,高于600 ng/g时抑制,对土壤放线菌则产生刺激效应。芘对土壤细菌、真菌和放线菌均产生抑制作用。(2)土壤中PCP能抑制土壤脲酶和蔗糖酶活性。菲在浓度低于300 ng/g时对土壤脲酶和蔗糖酶活性具有促进作用,而在浓度高于600 ng/g时对土壤脲酶和蔗糖酶活性具有抑制作用。芘对土壤脲酶活性具有抑制作用,在浓度低于150 ng/g时对土壤蔗糖酶活性促进,浓度高于300 ng/g时对土壤蔗糖酶活性抑制。(3)辽河口湿地和胶州湾湿地致癌风险评估结果表明,暴露于PAHs污染下的3类人群致癌风险值远小于10-6,无致癌风险。BaP和DBahA为主要的致癌风险贡献者。各暴露途径中,直接摄入和皮肤接触为主要的致癌暴露途径。敏感性分析表明,污染物浓度和暴露年限为最敏感参数。暴露PCP下不同人群均无致癌风险oRAGS模型估算的致癌风险值小于ILCR模型,这种评价结果的差异主要是由于两种模型所选取的致癌斜率因子不同所导致的。
[Abstract]:In recent years, with the rapid development of industrialization and urbanization, people have released a large number of pollutants to the environment, which has caused unprecedented environmental pressure on coastal wetlands. Some persistent organic pollutants (pops) are difficult to degrade. Easy to accumulate in the wetland environment, ecological environment and human health have potential harm. Further study on ecological effects and health risks of organic pollutants in wetland environment is of great significance for the protection of ecological environment and human health. Cyclic aromatic hydrocarbons (. Polycyclic Aromatic Hydrocarbons. PAHs and pentachlorophenol (PCPs) were used to study the effects of PCPP, phenanthrene and pyrene on soil microbes (bacteria, fungi) in coastal wetland soil. Effects of actinomycetes quantity and soil enzyme (urease and sucrase) activity. Two major coastal wetlands in China (Liaohekou wetland and Jiaozhou Bay wetland) were selected as the research objects. The carcinogenic risks of PAHs and PCP in coastal wetland soil were calculated through direct intake, skin contact and respiratory ingestion. In order to improve the accuracy of the evaluation results, two carcinogenic risk assessment models were used to calculate the carcinogenic risk, and the differences between the two models were compared in order to improve the accuracy of the evaluation results. In the process of health risk assessment, we successfully apply the probabilistic risk assessment (Monte Carlo simulation) to health risk assessment, and determine the key parameters that have the greatest impact on the accuracy of the evaluation results. In order to improve the accuracy of the evaluation results, the results show that the presence of PCP in the soil can promote the soil bacteria. Soil fungi were promoted at a concentration below 100 x 103 ng / g and inhibited at a concentration of 150 x 103 ng / g. The presence of phenanthrene in the soil could inhibit soil bacteria, while the concentration of soil fungi was less than 300ng 路g ~ (-1) 路g ~ (-1) 路g ~ (-1) 路g ~ (-1) 路g ~ (-1) 路g ~ (-1) ~ (-1). When the concentration of pyrene was higher than 600 ng/g, it had a stimulating effect on soil actinomycetes and pyrene on soil bacteria. Both fungi and actinomycetes produced inhibitory effects. (2) PCP could inhibit soil urease and sucrase activities. Phenanthrene promoted soil urease and sucrase activities when the concentration of phenanthrene was less than 300 ng/g. When the concentration was higher than 600 ng/g, the soil urease and sucrase activities were inhibited, and pyrene inhibited the soil urease activity. Soil sucrase activity was promoted when the concentration was less than 150 ng/g. The results of carcinogenic risk assessment of Liaohekou wetland and Jiaozhou Bay wetland showed that the inhibition of soil sucrase activity was higher than 300 ng/g. The carcinogenic risk values of the three groups of people exposed to PAHs pollution were much less than 10-6. The non-carcinogenic risk. Bap and DBahA were the main contributors of carcinogenic risk. Direct intake and skin contact were the main carcinogenic exposure pathways. Sensitivity analysis showed. The concentration of pollutants and exposure years were the most sensitive parameters. The carcinogenic risk estimated by oRAGS model was lower than that of ILCR model by oRAGS model without carcinogenic risk in different populations exposed to PCP. The difference is mainly due to the different carcinogenic slope factors selected by the two models.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

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