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1.
The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.  相似文献   

2.
Persistent organochlorine pesticides pollutants (OCPs) have been reported to occur at relatively high concentrations in some Chinese waters. In order to map the distribution of organochlorine pesticides in the surface water throughout China, samples were collected from over 600 sites in seven major river basins and three main internal rivers drainage areas during 2003 and 2004. The surface water samples were analyzed for the representative organochlorine pesticides contaminants including lindane (gamma-HCH), p,p'-DDT and heptachlor epoxide. In general, the most frequently detected compound was lindane, being detected in 83.9% of samples (mean=31.3 ng/l; range <0.17-860 ng/l), and the highest concentration was present in the Yellow River basin. p,p'-DDT was detected in 63.1% of the samples collected (mean=14.6 ng/l; range <0.14-368 ng/l) with the highest concentration present in the Huaihe River basin. Heptachlor epoxide was detected in only 9.3% of water samples (range <0.11-10 ng/l). Measured concentrations for the three compounds were low and rarely exceed the environment quality standard for surface water of China. Lindane was more frequently detected at much higher concentrations in the rivers of northern China compared with those of southern China. The sites with higher concentration of lindane and p,p'-DDT mainly occurred in the Yellow River and Huaihe River basins, so the results of this investigation indicate that the organochlorine pesticide contamination of Yellow River and Huaihe River basins should be of particular concern relative to the other basins. When compared with other regions of the world, it appears that the Chinese surface water is moderately polluted by lindane and p,p'-DDT.  相似文献   

3.
太湖流域沉积物中有机氯农药空间分布特征及风险评价   总被引:1,自引:0,他引:1  
为了解太湖流域表层沉积物中有机氯农药的空间分布和污染特征,采集全流域111个表层沉积物样品,用GC-μECD分析了20种有机氯农药的含量,并基于沉积物质量基准法对沉积物污染风险进行评价。结果表明:太湖流域沉积物中20种有机氯农药(OCPs)的总含量介于16. 3~96. 9 ng/g dw之间,平均值为35. 0ng/g dw,其中HCHs和DDTs是主要的检出成分,平均含量分别为12. 1、7. 6 ng/g dw,两者含量之和占总OCPs的25. 5%~85. 5%。特征化合物指数法分析结果表明,HCHs主要来源于林丹,而且该区域仍然有新的DDT输入,并且大部分p,p’-DDT通过好氧生物降解为p,p’-DDE。沉积物质量基准法评价结果显示,γ-HCH、DDTs潜在生物毒性较大。  相似文献   

4.
In the Republic of Bénin, aquatic ecosystems are subject to poisoning risks due to the inappropriate use of pesticides, such as washing of empty bottles in rivers and using pesticides to catch fish. In some areas, cotton fields are located near riverbanks, increasing the probability of pesticide emission to the river. To assess contamination levels in the Ouémé River catchment area, different fish species were collected from different geographical areas along the river. DDT, its metabolites and isomers were the most frequently identified pesticides in fish flesh, alpha-endosulfan, beta-endosulfan, dieldrin, telodrin, lindane and octachlorostyrene were also detected. Concentrations of pesticide residues in fish ranged from 0 to 1364 ng/g lipid. A preliminary risk assessment indicated that the daily intake of chlorinated pesticides by people consuming fish from the Ouémé River still is rather low and does not present an immediate risk.  相似文献   

5.
Nutrient chemistry of River Pinios (Thessalia, Greece)   总被引:2,自引:0,他引:2  
The impact of human activities with 3-year monitoring on the fluctuation of nutrients along the Pinios River and its tributaries were studied. Their seasonal variations throughout the years 1996-1998 were also presented. High temperatures, from June to August, cause a restriction of the water flow, an enhancement of nutrient concentration with the subsequent increase of eutrophication. High concentrations of nutrients were observed first in winter (wet period), caused by leaching of fertilizers from terrestrial systems after heavy rainfall, later during the warm months due to low water flow of the river, and at last in autumn when plant organisms began to decompose. The intensive algal and macrophyte growth (spring, summer) resulted in severe depletion of nutrients. Organic carbon showed no seasonal trend but its values were high near the estuaries. Nitrate fluxes were high at the initial station (sources) and the Titarisios tributary, whereas nitrites and ammonium were low. In contrary, the Kalentzis tributary with relatively low nitrate values showed increased values of nitrite ammonium or total nitrogen. On the other hand, the Enipeas tributary showed high SO4 values. Phosphates are remarkably present mainly after the city of Larissa, where sewage and industrial discharges occur. None of the nutrients measured in the Pinios River and its tributaries showed a clear seasonal cycle of concentration. Concentrations of nutrients and organic carbon increased as a consequence of anthropogenic inputs, particularly point discharges from sewage treatment plants (i.e. showing distinct, but variable, concentration peaks), as well as diffuse urban and/or agricultural runoff over long areas during storm events. The agricultural management, the urban pollution, mainly from Larissa City, and the climate conditions in the catchment basin (Thessalia Plain) of Pinios River and its tributaries greatly affect the chemical composition of their waters.  相似文献   

6.
Samples collected from rural and urban streams in the City of Denton, Texas, USA were analyzed for the organophosphorus pesticides diazinon and chlorpyrifos during the years preceding and following a United States Environmental Protection Agency ban on many chlorpyrifos uses. A network of 70 monitoring stations, based mainly on topography and hydrological considerations, were established within the three main watersheds of Denton. Monitoring stations were sampled monthly from March through August during periods of normal flow (baseflow), resulting in a total of 308 samples and 311 samples collected during 2001 and 2002, respectively. Pesticide concentrations were determined using commercially available enzyme-linked immunosorbent assays (ELISA) specific for each pesticide. Results from this temporally and spatially dense monitoring effort were used to illustrate the impacts of a ban on most chlorpyrifos sales that was imposed in December 2001. The total number of samples exhibiting concentrations above method lower limits of detection (LLD) decreased between 2001 and 2002 for both chlorpyrifos and diazinon. The total number of sites exhibiting at least one sample with concentrations above the LLD for chlorpyrifos, however, significantly decreased (Fisher's exact test, p<0.0001, n=70) when comparing 2001 (before the ban) with 2002 (after the ban). Similar analyses indicated no significant difference (Fisher's exact test, p=0.50, n=70) in the number of sites exhibiting detectable diazinon concentration between 2001 and 2002. Our results indicate that the cessation of retail chlorpyrifos sales at the end of 2001 resulted in a highly significant decrease in the surface water occurrences of this pesticide during 2002.  相似文献   

7.
Environmental pollution is a recognized issue of major concern since a wide range of contaminants has been found in aquatic environment at ng L 1 to μg L 1 levels. In the year 2000, a strategy was defined to identify the priority substances concerning aquatic ecosystems, followed by the definition of environmental quality standards (EQS) in 2008. Recently it was launched the Directive 2013/39/EU that updates the water framework policy highlighting the need to develop new water treatment technologies to deal with such problem. This review summarizes the data published in the last decade regarding the application of advanced oxidation processes (AOPs) to treat priority compounds and certain other pollutants defined in this Directive, excluding the inorganic species (cadmium, lead, mercury, nickel and their derivatives).The Directive 2013/39/EU includes several pesticides (aldrin, dichlorodiphenyltrichloroethane, dicofol, dieldrin, endrin, endosulfan, isodrin, heptachlor, lindane, pentachlorophenol, chlorpyrifos, chlorfenvinphos, dichlorvos, atrazine, simazine, terbutryn, diuron, isoproturon, trifluralin, cypermethrin, alachlor), solvents (dichloromethane, dichloroethane, trichloromethane and carbon tetrachloride), perfluorooctane sulfonic acid and its derivatives (PFOS), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), nonylphenol and octylphenol, as well as the three compounds included in the recommendation for the first watch list of substances (diclofenac, 17-alpha-ethinylestradiol (EE2) and 17-beta-estradiol (E2)). Some particular pesticides (aclonifen, bifenox, cybutryne, quinoxyfen), organotin compounds (tributyltin), dioxins and dioxin-like compounds, brominated diphenylethers, hexabromocyclododecanes and di(2-ethylhexyl)phthalate are also defined in this Directive, but studies dealing with AOPs are missing.AOPs are recognized tools to destroy recalcitrant compounds or, at least, to transform them into biodegradable species. Diuron (a phenylurea herbicide) and atrazine (from the triazine chemical class) are the most studied pesticides from Directive 2013/39/EU. Fenton-based processes are the most frequently applied to treat priority compounds in water and their efficiency typically increases with the operating temperature as well as under UV or solar light. Heterogeneous photocatalysis is the second most used treatment to destroy pollutants defined in the Directive. Ozone alone promotes the partial oxidation of pollutants, and an increase in the effluent biodegradability, but complete mineralization of pollutants is difficult. To overcome this drawback, ozonation has been combined with heterogeneous catalysts, addition of H2O2, other AOPs (such as photocatalysis) or membrane technologies.  相似文献   

8.
Regional Environmental Change - Water governance in the South Saskatchewan River Basin (SSRB), a transboundary river basin in western Canada, occurs in one of the world’s most decentralized...  相似文献   

9.
按照流域尺度从小到大,分别选择新安江流域、珠江流域和长江流域作为研究对象,通过实证分析发现上下游水环境库兹涅茨曲线遵从一定的演递规律,即上游地区往往会重复下游地区的曲线过程,但其发展阶段落后于下游地区。上下游的发展差异越大,这种规律表现得越明显。产生这一规律的主要原因是我国多数流域下游地区的经济发展水平一般高于上游地区,下游比上游更早地到达了环境库兹涅茨曲线的峰值,并具有了更强的环境保护能力。这一规律有助于深化对上游水资源保护的重要性的认识。国家和下游地区需要加强对上游欠缺的生态环境保护能力的支持和援助,降低上游水环境库兹涅茨曲线的峰值和曲率,从长远意义上减轻上游发展过程中对全流域生态环境产生的不利影响和生态保护代价。  相似文献   

10.
Ethiopia has accumulated obsolete pesticide stocks since pesticides were first imported in the 1960s due to prolonged storage of pesticides, inappropriate storage conditions because of poor storage facilities, the lack of trained staff and lack of national legislation for pesticide registration and monitoring system of pesticide use in the country. The first pesticide inventory conducted in 1995 led by FAO in collaboration with the government of Ethiopia had identified about 426 tonnes of obsolete pesticides mainly on state-owned agricultural farms and held by the Ministry of Health. However, these stocks have increased to over 1500 tonnes (including 200 active ingredients) as found in a detailed inventory conducted in 1999. The stocks included organochlorines (258.3 tonnes), organophosphates (155.4 tonnes), carbamates (58.5 tonnes), coumarines (14.9 tonnes), inorganics (30.2 tonnes), others (257.2 tonnes), mixed pesticides (70.4 tonnes) and unknown pesticides (307.1 tonnes) including both liquid and solid state formulations. The obsolete organochlorine pesticides stocks were mostly pesticides such as chlordane, DDT, dieldrin and lindane that are banned or restricted in most countries. The highest amount of a single active ingredient found was the organophosphate insecticide pirimiphos methyl (172.1 tonnes). All these stocks were disposed of in the first phase of disposal in Finland (during 2000–2003) by the hazardous waste management company Ekokem at a cost of about US$ 4.44 million. Another 1000 tonnes of obsolete pesticides have been identified and are currently being eliminated in a second disposal phase at a total cost of US$ 8 135 500. Along with the disposal process, a number of activities are being implemented to prevent future pesticides accumulation. These activities include the development and enforcement of pesticide policy, the implementation of Integrated Pest Management (IPM) and Integrated Vector Management (IVM), capacity building in terms of providing professional trainings, creating awareness among stakeholders on the environmental and human health hazard posed by obsolete pesticides as well as other actions to prevent their accumulation and enforcement of national legislations and policies related to pesticides use. However, pesticide use in the country is increasing. For instance, 12 years of pesticides import data (1996–2007) by the Ministry of Agriculture shows that 2973 tonnes of pesticides were imported between 1996–1998, 3670 tonnes between 1999–2001, 5079 tonnes between 2002–2004 and 8302 tonnes between 2005–2007. Moreover, 6 years of insecticide import data (1996/97–2001/02) by the Ministry of Health shows that around 919 tonnes of insecticides were imported between 1996/97–1997/98, 812 tonnes between 1998/99–1999/00 and 970 tonnes between 2000/01–2001/02 for malaria and other vector borne diseases control.  相似文献   

11.
12.
淮河(江苏段)水体有机污染物风险评价   总被引:10,自引:2,他引:8  
淮河(江苏段)水体检测到的半挥发性有机物和有机氯农药绝大多数属于USEPA的优先控制污染物。应用USEPA规定的水中优先控制污染物和非优先控制污染物对人体健康的摄入与饮入之和的水体有机物浓度标准,计算了淮河(江苏段)水体的48种有机污染物的环境暴露浓度,并根据最高环境暴露浓度与USEPA水质指标的比值,参考IARC的化合物致癌性指标,建立了一套表征水体有机污染物的风险特征以及采取相应管理措施和建议的评价体系,对这些化合物的环境健康风险进行了评价。结果表明,有18种有机污染物超过了USEPA的标准浓度要求,其中9种物质具有一定的生态风险,其中六氯苯、N-亚硝基二正丙胺、3,3'-二氯联苯胺、2,4,6-三氯酚、五氯酚、茚并(1,2,3-cd)芘、4,4'-滴滴涕、七氯在内的8种化合物具有一定的风险,而多环芳烃二苯并(a,h)蒽需要引起更高警惕;在此基础上探讨了这些化合物的来源及作用,并提出了相应的防治建议。  相似文献   

13.
黄河流域生态保护和高质量发展已成为重大国家战略,流域内的经济增长、产业发展与生态环境协同发展问题正逐渐成为研究热点。文章分析了黄河流域经济增长、产业发展与生态环境三者的耦合协同机理。在此基础上构建耦合协同综合评价指标体系,运用耦合协调度模型、空间自相关模型、灰色关联模型分析了2012—2018年黄河流域62个地级市经济增长、产业发展与生态环境各系统的综合水平及三者耦合协调度的时空差异及其驱动因素。运用GM(1,1)灰色预测模型预测了短期内三者耦合协调度的变化趋势。研究表明:①黄河流域经济增长、产业发展与生态环境各系统综合水平总体上呈现平稳态势,三者发展速度差异不明显,但耦合协同严重失调,黄河流域整体尚未达到三者协同发展状态。②黄河流域经济增长、产业发展与生态环境三者的耦合协调度呈现出显著的空间自相关性,全局空间自相关为正,局部空间自相关呈现出聚集趋同特征。③预测结果表明黄河流域经济增长、产业发展与生态环境三者的耦合协同发展在短期内保持平稳。在预测期内黄河流域经济增长、产业发展与生态环境仍未达到协同发展状态,部分地区的耦合协调度有所提高,但总体提升与演进的速度较缓慢。最后,基于黄河流域经济发展与生态环境保护分析,为黄河流域经济增长、产业发展与生态环境耦合协同构建了包含组织保障、空间治理、政策保障以及体制机制等支撑体系,以期为实现黄河流域高质量发展奠定科学决策基础。  相似文献   

14.
Surface waters located in intensive agricultural areas are more vulnerable to the pesticides contamination, which is a major concern if the water is intended to be used for human consumption. The aim of this study was to evaluate the presence and the distribution of pesticides in the Alqueva reservoir, an important source of water supply (South of Portugal), considering their representativeness in the agricultural practice of the area. For the analysis of pesticides risk impact we used the environmental quality standards in the field of water policy proposed recently by the European Commission. The pesticides belonging to the classes of phenylureas, triazines, chloroacetanilides, organophosphorous and thiocarbamates were analysed by on-line solid phase extraction-liquid chromatography-tandem mass spectrometry. The pesticides more frequently detected were atrazine, simazine, diuron and terbuthylazine. The highest levels of these pesticides were registered in spring, after pesticides treatment, namely in olive-tree and vine crops. The priority pesticides atrazine and diuron reached values above the annual average proposed in the European Union Legislation. The herbicide atrazine reached values that surpassed the proposed maximum allowable concentration (2 000 ng L? 1). The sampling stations most affected by these pesticides were Sra. Ajuda, Lucefecit and Alcarrache, located in the northern part of the reservoir, closer to Spain where the agricultural activity is more intensive.  相似文献   

15.
In Pakistan there is little data on environmental contamination of rural water sources by pesticides. This study evaluated pesticide contamination of groundwater in four intensive cotton growing districts. Water samples were collected from 37 rural open wells in the areas of Bahwalnagar, Muzafargarh, D.G. Khan and Rajan Pur districts of Punjab and analysed for eight pesticides which are mostly used. Information on types of pesticide used and distance to nearest pesticide mixing area and application areas was obtained for each site. From the eight pesticides analysed, six pesticides were detected in the water samples. Only cypermethrin and cabosulfan were not detected. The percentage of detection of bifenthrin, lambda-cyhalothrin, carbofuran, endosulfan, methyl parathion and monocrotophos was, respectively 13.5%, 5.4%, 59.4%, 8%, 5.4% and 35.1% in July; 16.2%, 13.55%, 43.2%, 8%, N.D. (not detected) and 24.3% in October. Maximum contamination levels (MCLs) established by the U.S. Environmental Protection Agency for drinking water were not exceeded. The study has shown the need for monitoring pesticide contamination in rural water resources, and the development of drinking water quality standards for specific pesticides in Pakistan. The conclusions and recommendations will be disseminated to senior decision makers in central and local governments, extension agents and farmers.  相似文献   

16.
从长江流域生态系统长期演化的视角,分析了长江流域自然与湿地环境演变特征,归纳了长江流域湿地资源概况,分别总结了长江源区、三峡库区湿地区、中游湖泊群以及长江三角洲湿地的区域性特征及其面临的威胁因素,论述了典型重要湿地区域湿地保护与生态工程建设的示范案例,在此基础上探讨了长江流域湿地保护、修复与生态管理的对策和建议,旨在助力于长江大保护,为长江流域湿地的保护和科学管理提供依据。  相似文献   

17.
Analyses of environmentally persistent pollutants like polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, and dichlorodiphenyltrichloroethane (DDT) and its metabolites in seawater and sediment samples collected from six locations along the east coast of India were carried out using High-Resolution Gas Chromatograph with High-Resolution Mass Spectrometer (HRGC-HRMS). Sediment and water from Chennai harbour and Cuddalore fishing harbour contained higher concentration of all the compounds. The highest concentration (6570 pg/g dry weight) of total PCB was found in sediment from Chennai harbour followed by sediments sampled in Chennai (opposite to Cooum River mouth) (505 pg/g), Cuddalore fishing harbour (335 pg/g) and Mandapam (251 pg/g). Concentrations in other locations were two orders of magnitude lower than Chennai harbour. A distinct PCB distribution pattern in sediment was observed between harbours and other locations. Greater concentrations of tetra-, penta- and hexachlorobiphenyls were observed in sediments of harbours and opposite to Cooum river mouth, but in other locations lower chlorinated biphenyls (di, tri and tetra-) were more. In seawater, HCH concentration was greater than DDT, but it was quite opposite in sediments. Elevated levels of DDT in sediment were observed only at highly populated urban locations, reflecting the local usage and input of this pesticide. Based on sediment/water quality criteria/guidelines, some coastal locations of the Bay of Bengal could be designated as being polluted by DDTs and gamma-HCH (lindane), but not by PCBs. This investigation reveals the declining trend on the environmental burden of persistent pesticides in Indian marine environment. Data on the organochlorine concentrations found in this survey can be used as reference levels for future POPs monitoring programme.  相似文献   

18.
鄱阳湖流域基本特征、面临挑战和关键科学问题   总被引:2,自引:0,他引:2  
鄱阳湖流域总面积占长江流域面积的9%,占江西省国土面积的939%,鄱阳湖流域的生态健康维系着流域内,特别是长江中下游的生态安全,是区域经济、社会、生态可持续发展的重要保障。在全面认识鄱阳湖流域基本特征和面临挑战的基础上,探讨了鄱阳湖流域面临的五大科学问题:“山 江 湖”的相互关系与流域的生态健康;全球变化背景下流域生态系统的响应;流域生物多样性地理格局与社会经济合理分区;长江流域环境演变对鄱阳湖流域的影响;流域科学管理的理论与实践。为鄱阳湖生态经济区的建设和全流域的综合管理提供科学的建议和对策  相似文献   

19.
BackgroundEnvironmental pollutants such as dioxins and PCBs, heavy metals, and organochlorine pesticides are a global threat to food safety. In particular, the aquatic biota can bioaccumulate many of these contaminants potentially making seafood of concern for chronic exposure to humans.ObjectivesThe main objective was to evaluate trends of contaminant levels in Norwegian farmed Atlantic salmon in light of the derived tolerable intakes.MethodsThrough an EU-instigated surveillance programme, the Norwegian Food Safety Authority (NFSA) has between 1999 and 2011 collected more than 2300 samples of Norwegian farmed Atlantic salmon (Salmo salar) for contaminant analyses. The fillets of these fish were homogenised and analysed for dioxins, PCBs, heavy metals and organochlorine pesticides.ResultsThe levels of the contaminants mercury, arsenic, dioxins, dioxin-like PCBs and DDT in Norwegian farmed salmon fillet have decreased during our period of analyses. The levels of cadmium, lead and several organochlorine pesticides were too close to the limit of quantification to calculate time trends. For PCB6 and quantifiable amounts of pesticides, except DDT, stable levels were observed.ConclusionThe contaminant levels in Norwegian farmed salmon have generally decreased between 1999 and 2011. Excluding other dietary sources, the levels of dioxins and dioxin-like PCBs in 2011 allowed consumption of up to 1.3 kg salmon per week to reach the tolerable weekly intake. The group of contaminants which was the limiting factor for safe consumption of Norwegian farmed salmon, based on currently established TWI values, is the sum of dioxins and dioxin-like PCBs.  相似文献   

20.
In case of an avian-influenza-derived human flu pandemic, an inordinately high use of medicines over several weeks is predicted, in particular for the recommended influenza antiviral oseltamivir (Tamiflu). While the risk of oseltamivir to sewage works and freshwater bodies has already been assessed, the fact that a large percentage of the human population worldwide lives relatively close to the sea raises concern for its environmental compatibility in coastal marine waters. The potential risk of high oseltamivir use to the marine compartment is assessed in this publication, based on the 2003 European Community Technical Guidance Document (TGD) for risk assessment. Subchronic embryo–larval ecotoxicity tests with three marine invertebrates (Pomatoceros triqueter, Annelida; Mytilus edulis, Mollusca; Paracentrotus lividus, Echinodermata) and chronic growth inhibition tests with two different groups of marine microalgae (Isochrysis galbana, Haptophyta; Skeletonema costatum, Heterokontophyta) were performed with the active substance oseltamivir carboxylic acid to derive a dependable marine predicted no-effect concentration (PNEC). This was compared to a predicted environmental concentration (PEC) for oseltamivir in coastal waters, based on the worst-case freshwater PEC. The PEC/PNEC risk characterisation ratio for the marine compartment is well below 1, which in the terminology of the TGD signifies no immediate concern. Further, while oseltamivir may be persistent (P), it is not bioaccumulative (B) nor highly ecotoxic (T) and therefore not a PBT substance. In conclusion, even a high pandemic use of oseltamivir would not lead to a significant risk for the marine compartment, in confirmation of the risk assessment for sewage works and freshwaters.  相似文献   

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