Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.16.2 (PCP)
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The distribution and metabolic fate of several rice paddy pesticides were evaluated in a modified model ecosystem. Among the three BHC isomers, beta-isomer was the most stable and bioconcentrated in all of the organisms. Alpha- and gamma-isomers were moderately persistent and degraded to some extent during the 33 day period. Disulfoton was relatively persistent due to the transformation to its oxidation products. Pyridaphenthion was fairly biodegradable. N-Phenyl maleic hydrazide derived from the hydrolysis of pyridaphenthion was not detected in the organisms though it was found in the aquarium water after 33 days. Cartap and edifenphos were considerably biodegradable, and the ratio of the conversion to water soluble metabolites was very high. There was a distinct difference in the persistence of Kitazin P and edifenphos in the aquarium water. It appeared that the hydrolysis rate of the pesticides affected their fate in the organisms. PCP appeared to be moderately biodegradable. CNP was considerably stable and stored in the organisms though the concentration in the aquarium water was relatively low. The persistence and distribution of the pesticides in the model ecosystem were dependent on their chemical structures. In spite of the limitation derived from short experimental period, the model ecosystem may be applicable for predicting the environmental fate of pesticides.
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PMID:Environmental fate of rice paddy pesticides in a model ecosystem. 43 58

Long term environmental fate of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were studied using the fugacity-based dynamic multimedia environmental fate model. New formulation about soil wind erosion into air was included into the model. Effect of process assumption, sensitivity analysis for parameters, and tentative validation against the measured sediment core analysis was performed. Mass fluxes between compartments were estimated by the dynamic modeling. From the model estimates, major mass fluxes coming from emission source were shown to go to the soil and water through wet/dry deposition, then go to degradation mainly in the soil and sediment. Major mass fluxes of TCDD and OCDD come from the impurities in CNP (Chlornitrofen) and PCP (Pentachlorophenol) directly into the soil. Consideration about multimedia environmental dynamics using the modeled mass fluxes was shown in the discussion.
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PMID:Simulation of long-term environmental dynamics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans using the dynamic multimedia environmental fate model and its implication to the time trend analysis of dioxins. 1073 34

Various types of endocrine disruptors or environmental hormones flow from their sources down into harbours through rivers and other watercourses, and are accumulated in sediment on the sea bottom. Tributyltin, which has been used as paint for ship bottoms, is considered one of the endocrine disruptors. In close cooperation with the other ministries and agencies, the Ports and Harbours Bureau of the Ministry of Land, Infrastructure and Transport carried out an investigation in 1999 to determine the actual condition of 12 endocrine disruptors in the sediment of 39 harbours, in order to gather fundamental data to be used in future examinations of policy. Furthermore, in 2000 the bureau chose seven harbours out of the above 39 harbours as subjects of an additional investigation regarding the surface distribution of endocrine disruptors in the harbour areas and the synchronistic change of accumulation of dioxin and other substances. As the result of the investigation regarding the surface distribution of endocrine disruptors accumulated in seven harbours, relatively high concentrations were measured in the innermost parts of harbours and the mouths of rivers. Synchronistic changes in the amount of dioxin and other substances accumulated in sediments of five harbours were determined. Small amounts of dioxin and other substances, including an especially small amount of coplanar-PCBs, were found in the layers formed before or around 1950. Relatively large amounts of these substances were measured in the upper layers formed during roughly 1960-1990, though no significant yearly differences in concentration could be identified. This result coincides with the facts that, during roughly 1960-1980, PCP and CNP were used as agricultural chemicals and full-scale production of PCBs started in 1960.
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PMID:The nationwide investigation of endocrine disruptors in sediment of harbours. 1278 9

The vertical distribution of dioxins in a sediment core was investigated to elucidate historical trends of dioxins discharged into Sendai Bay, Japan. The dioxin concentration was 410 pg/g dry weight (dw) in sediments deposited in the mid-1930s and 3870 pg/g dw in those deposited in the mid-1980s. Dioxin fluxes increased from the mid-1930s and then reached a maximum in the mid-1980s. 1,3,6,8-TeCDD+1,3,7,9-TeCDD, OCDD, and Co-PCB concentrations were 110, 140, and 26 pg/g dw, respectively, in mid-1930s sediments, and reached maximums of 1800, 1100, and 200 pg/g dw, respectively, in mid-1980s sediments. Shipments to Miyagi Prefecture of CNP and PCP products, the major sources of 1,3,6,8-TeCDD+1,3,7,9-TeCDD and OCDD, were highest in 1975 (4700t) and 1970 (3100t), respectively; and in Japan, the amount of PCBs, the major source of Co-PCB congeners, used was highest (11,100t) in 1970. Thus, the period for which the maximum concentrations of 1,3,6,8+1,3,7,9-TeCDD, OCDD, and Co-PCBs were measured in the sediment core (mid-1980s) did not correspond to the time of maximum use of CNP, PCP, or PCB products, but lagged behind by more than 10 years. We attributed this time lag to the time required for the movement of dioxins from Miyagi Prefecture to Sendai Bay.
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PMID:Historical trends of PCDD/Fs and CO-PCBs in a sediment core collected in Sendai Bay, Japan. 1532 77

The temporal variations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in 33 agricultural soil samples in the vicinity of a municipal solid waste incinerator (MSWI) in Eastern China were determined one year after the initial investigation in 2006. The soil PCDD/F concentrations in 2007 ranged from 73.6 to 377 ng kg(-1) (0.60-6.38 ng I-TEQ kg(-1)). During 2006-2007, the overall soil PCDD/F levels increased significantly, i.e., 33% and 39% for total concentration and I-TEQ (median value), respectively. Moreover, soils in the study area are proved to be almost free from previously suspected PCDD/F sources, i.e., pentachlorophenol/sodium penta-chlorophenate (PCP/PCP-Na) and 1,3,5-trichloro-2-(4-nitrophenoxy) benzene (CNP) contaminations. Furthermore, the results from a congener-specific factor analysis between soils (collected in two investigations) and dioxin emission sources suggest that diffuse sources including open burning of wastes, traffic and hot water boilers are major contributors that are responsible for the accumulation of PCDD/Fs in soils. By contrast, the impact of the presumably major PCDD/F source identified in our previous study, i.e., the MSWI, seems to be limited.
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PMID:Agricultural soil monitoring of PCDD/Fs in the vicinity of a municipal solid waste incinerator in Eastern China: temporal variations and possible sources. 1913 6