Studies On Environmental Geochemistry Behaviors Of Organochlorine Pesticides In Environmental Mediums From The Yellow River Estuary

Organochlorine pesticides (OCPs) as an important class of typical persistent organic pollutants in the environment, it is difficult to oxidation, degradation of long cycle and high toxicity, the pollution and harm to ecological environment and human health has caused widespread concern around the world. The distribution, migration, transformation and ecotoxicological effects of OCPs in the coastal region is to explore its global distribution, migration behavior and the pollution level,In this thesis, organochlorine pesticides in water, soil, sediments and sedimentary column from the Yellow River estuary is as the research object, Solid phase extraction, Soxhlet extraction, gas chromatography-mass spectrometry, principal component analysis, isotopic dating, mathematical models and other direct and indirect test and analysis method are used. Study on the occurrence regularity, potential ecological risk, human health risk, the historical settlement record and input source of OCPs in different medium is to explore the behavior and fate of organochlorine pesticides and exchange rules in different medium.The main results are obtained in the following aspects through the study:(1) The method for analysis of organochlorine pesticides was established in multi media system, Methods of the detection limits for water samples and solid samples are0.001-0.01ng/L and0.001-0.004ng/g, respectively. They are superior to the similar reports in the literature; the recovery rate is in the range of75%-102%, the relative standard deviation is in the0.2%-10%, The detection limit was superior to similar reports in the literature, the recovery rate and standard deviation was in accordance with the requirements of USEPA, the method can be applied to the analysis of organic chlorine pesticide in the environment of multi media.(2) According to the distribution rules research of the organic chlorine pesticide in different medium phase,It was revealed the organic chlorine pesticide in regional environmental medium source from the redistribution of organochlorine pesticides in the environment in this study. HCHs tend from to the water to sedimentary facies deposition, DDTs tend to release by sedimentary to water phase.(3) The settlement dating recording of organic chlorine pesticides was studied by using210Pb isotope. It was revealed the settlement record changes of organochlorine pesticides during the years1925-2005was related with the past history use and soil residue.(4) The characteristics of the content, distribution, source, destination, risk, and their environmental behaviors of organic chlorine were studied systematically for the first time in multimedia environment from the the Yellow River estuary. It was found HCHs and DDTs in environmental media are existed in the form of β-HCH and DDE, which was mainly due to degrading difficultly in environment; The source analysis showed that the pesticide in the study area was mainly from the historical residue. Recently there are a large number of Lin Dan used in industrial. Correlation analysis between organochlorine pesticides compounds have revealed the migration of similar in different media. Risk assessment showed that the γ-HCH and p’p-DDE will cause more ecological risk. The carcinogenic risk of β-HCH should cause height to take seriously, the cancer risk of organochlorine pesticide in the region was low.