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731.
The residue levels of presistent chlorinated pesticides such as HCH (hexachlorocyclo-hexane) isomers and DDT (dichlorodiphenyl trichloroethane) compounds were quantified in water samples collected from the River Kaveri and its distributor River Coleroon in Tamil Nadu, South India. HCH showed higher levels in River Kaveri during premonsoon (July to September) and monsoon (October to December) months, reflecting the HCH usage during that season for paddy crops. But in the case of DDT no clear trend in residue level was observed. the α-HCH was detected as the dominant isomer in all the three sampling sites. Among DDT compounds, p,p'-DDT and p,p'-DDE showed higher percentage of the total. International comparison of residue levels revealed that the present values are comparable to the waters from Asian and South East Asian nations, but lower than some samples from other parts of India. the value of DDT is well below the EEC's maximum acceptable concentration for surface waters and lower than the recommended limit of 2000ng 1-1 in USA water for protection of aquatic life (Water Quality Criteria, 1972).  相似文献   
732.
Butyltin compounds (BTs) and organochlorine residues (OCs) were determined in green mussel (Perna viridis L.) collected along the coastal waters of India in 1994 and 1995 to elucidate their contamination levels and distribution. BTs were detected in all of the mussel samples, ranging from 2 to 378 ng/g wet wt, which indicated that BTs are widely distributed, with elevated concentrations in intense boating areas. BTs concentrations in green mussels were lower than those reported for developed nations as well as developing countries such as Thailand. Concentrations of OCs were much lower than those of BTs. Among OCs examined, DDTs were found to be greatest, followed by HCHs, PCBs, CHLs and HCB. Considering the fact that the usage of tributyltin (TBT), DDTs and HCHs are not controlled in India, their contamination in the aquatic environment may increase unless regulatory measures are imposed. To our knowledge, this is a first report on the detection of BTs in Indian mussels.  相似文献   
733.
为探讨基于FH插值法构建的二元有机磷混合物联合作用新模型在等效线图法中的应用,选择野生型秀丽隐杆线虫(Caenorhabditis elegans)为受试生物,测定敌敌畏(DDVP)和久效磷(MCP)的单一毒性以及二元联合毒性;依据单个农药作用线虫4 h的急性毒理试验结果,以等效线图法原理绘制30%、50%和70%线虫死亡效应的浓度加和等效线及置信区间(CI);利用二元混合农药联合作用结果,基于FH插值法建立二元有机磷农药混合物联合作用模型;利用等高线与混合物联合作用曲面,绘制30%、50%和70%线虫死亡效应下混合农药的观测等效线。结果表明:DDVP、MCP单一作用线虫4 h的LC30、LC50和LC70及CI分别为35.40(26.85~41.64)、43.55(36.00~50.76)、53.58(45.99~64.95)μmol·L~(-1)和13.15(9.12~16.07)、16.96(13.35~20.55)、21.87(18.11~28.36) mmol·L~(-1); 30%、50%和70%线虫致死效应的观测等效线均在加和等效线置信区间内,表明DDVP与MCP混合农药的联合作用表现为相加作用,与多元统计分析结果一致。上述研究实现了对二元有机磷农药混合物联合作用下任一效应观测等效线的预测,并为全面有效地评价二元混合物联合作用效应提供了新的方法。  相似文献   
734.
The concentration of organochlorine pesticides(OCPs) in tissues and organs of silver carp(Hypophthalmichthys mofitrix) from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight(ww) for total OCPs, 0.16- 0.75 ng/g ww for HCB. 0.75 -26.80 ng/g ww for SHCH(sum of α-,β-, γ- and δ-HCH) and 0.68-35.94 ng/g ww for SDDT( sum of p, p'-DDE, p, p'-DDD, o, p'-DDT and p, p'- DDT). The mean concentrations of total OCPs, HCB, ∑HCH, and ∑DDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, β-HCH and p, p'-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.  相似文献   
735.
活性炭纤维萃取浓缩水样中微量有机磷农药   总被引:1,自引:1,他引:0  
采用活性炭纤维(ACF)为固相萃取剂填料,萃取测定水样中微量有机磷农药。研究分析了ACF用量、洗脱剂类型、农药初始质量浓度、水样过柱速度及pH等因素对萃取回收率的影响。结果表明:洗脱剂类型和ACF用量是显著的影响因素。最佳萃取条件为:含0 1μg L有机磷农药的1L加标水样,需0 2gACF和8mL二氯甲烷,水样过柱速度40mL min。pH对萃取影响不大。萃取回收率为80 7%~118%。   相似文献   
736.
蔬菜中有机磷农药残留的生物传感器法检测   总被引:7,自引:0,他引:7  
将乙酰胆碱酯酶(AChE)固定在醋酸纤维膜上,将该膜组装在一支pH玻璃电极敏感膜表面,制成用于测定有机磷农药的电位型生物传感器,优化其制备方法。当溶液中存在有机磷农药,酶的活性受到抑制,酶活性的降低引起pH玻璃电极电位的改变,其改变程度与溶液中农药的浓度大小有关。用本文方法测定了蔬菜中的对硫磷、辛硫磷、氧乐果、敌敌畏,结果满意。  相似文献   
737.
北京市郊再生水灌区土壤有机氯农药垂向分布特征   总被引:3,自引:0,他引:3  
在北京市郊再生水灌区采用正三角型布点法进行了3个钻孔的采样工作,钻孔间隔为1m,从表层开始每隔0.5m取一个样,3个钻孔共36组样品,同时采集钻孔附近的灌溉水及地下水,分别测试了土壤的理化参数及其土壤、灌溉水及地下水中9种有机氯农药的质量分数。测试结果表明:表层土壤是有机氯农药的主要残留层,表层土壤中检出的DDTs和BHCs质量分数较高,分别为2814.21ng·kg^-1和1130.41ng·kg^-1,但均符合土壤环境质量一级标准,残留污染程度较轻;其他层位以七氯和艾氏剂为主要检出物,最高质量分数分别为1286.19ng·kg^-1和781.23ng·kg^-1;其中艾氏剂未在表层土壤中检出;灌区内未检出的γ-BHC和(DDE+DDD)/DDT的计算值为1.80,都说明近期内没有新污染源的输入;检出的有机氯农药在土壤剖面上的迁移能力有HEP〉ALD〉BHCs〉DDTs〉HCB,与地下水中检出的规律一致。  相似文献   
738.
农药和化肥对无尾两栖类蝌蚪的毒性效应研究进展   总被引:4,自引:0,他引:4  
以两栖动物研究环境污染物的毒性效应进而监测环境的变化,已成为国内外的研究热点.两栖类的胚胎发育和变态过程对水的依赖性极强,而且鳃和皮肤有很强的渗透性,当其受到污染胁迫时,在细胞、组织及生理生化水平上都会发生显著变化,进而会影响其存活和生长发育.在总结国内外相关研究基础上,综述和分析了农药、化肥(氮肥)对无尾两栖类蝌蚪的行为表现、生长发育、组织结构和生理生化变化等方面的毒性效应,以期为农药、化肥的水环境监测及合理使用提供全面的科学依据.  相似文献   
739.
为初步了解青岛近海生物体内多环芳烃、多氯联苯和有机氯农药的含量和组成特征,于2007年10~11月采集了青岛近海13个站位的鱼、虾和软体类动物,分析了其肌肉中的多环芳烃、多氯联苯和有机氯农药的含量和组成.结果表明,多环芳烃、多氯联苯和有机氯农药更易在鱼类体内富集,其含量远大于软体类和虾类.高氯代联苯和高环芳烃在同系物中的比例在鱼类体内最小,这可能是由鱼类和虾类、软体类不同的生活习性造成的.有机氯农药中,滴滴涕的含量显著高于六六六.  相似文献   
740.
Contaimination of anguillid eels by organochlorine pesticides and PCBs is reviewed using a risk assessment-management approach. Quantitative structure-activity relationships, biomonitoring of body residues and field and laboratory studies demonstrate hazards and risks of persistence; organic carbon binding, sediment transport and sinks; volatility, aerial transport and deposition; hydrophobicity/lipophilicity, bioaccumulation, bioconcentration and dietary biomangification. Risks of acute narcotic toxicity are generally lower than those of chornic effects. Cause-effect relationships and critical loadings are, however, unclear. Critical environmental and body residue levels to protect eels and animal and humans consumption must be formulated and interpreted with caution. Risks for eels at different life-stages and in different habitats are compared with respect to routes of uptake, elimination, bioaccumulation and biomagnification. It is concluded that organochlorine contamination has not been a major cause of recent declines in eel recruitment. the use of eels in biomonitoring and biomarker studies are recommended. Appropriate methodologies and uses in risk assessment and management are discussed.  相似文献   
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