Studies on urban drinking water quality in a tropical zone

Anthropogenic activities associated with industrialization, agriculture and urbanization have led to the deterioration in water quality due to various contaminants. To assess the status of urban drinking water quality, samples were collected from the piped supplies as well as groundwater sources from different localities of residential, commercial and industrial areas of Lucknow City in a tropical zone of India during pre-monsoon for estimation of coliform and faecal coliform bacteria, organochlorine pesticides (OCPs) and heavy metals. Bacterial contamination was found to be more in the samples from commercial areas than residential and industrial areas. OCPs like α,γ-hexachlorocyclohexane and 1,1 p,p-DDE {dichloro-2, 2-bis(p-chlorophenyl) ethene)} were found to be present in most of the samples from study area. The total organochlorine pesticide levels were found to be within the European Union limit (0.5 μg/L) in most of the samples. Most of the heavy metals estimated in the samples were also found to be within the permissible limits as prescribed by World Health Organization for drinking water. Thus, these observations show that contamination of drinking water in urban areas may be mainly due to municipal, industrial and agricultural activities along with improper disposal of solid waste. This is an alarm to safety of public health and aquatic environment in tropics.     

Organochlorine pesticide residues in drinking water in the rural areas of Haryana,India

Drinking water samples collected from rural areas of three districts of Haryana during pre-monsoon and post-monsoon periods were analysed for the presence of organochlorine pesticide residues. The main source of drinking water in rural areas, i.e. groundwater in Ambala and Gurgaon districts and surface water supply in Hisar district, was found to be contaminated with isomers of HCH and endosulfan and metabolites of DDT, whereas dieldrin remained below detection limits. During the study period, the mean values observed for total HCH, DDT and endosulfan were 87.6, 848.2, and 27.4 ng/L and 99.8, 275.3 and 164.2 ng/L, respectively, for Ambala and Gurgaon districts. In the case of Hisar district, the values were 78.5, 115.9, and 53.0 ng/L, respectively. During the study period, 37% of the samples exceeded the total pesticide level of 500 ng/L indicated in the EECD directive for drinking water. Seasonal variations of pesticide residues were also observed during the study period.     

Organochlorine pesticide residues in ground water of Thiruvallur district, India

Modern agriculture practices reveal an increase in use of pesticides and fertilizers to meet the food demand of increasing population which results in contamination of the environment. In India crop production increased to 100% but the cropping area has increased marginally by 20%. Pesticides have played a major role in achieving the maximum crop production, but maximum usage and accumulation of pesticide residues was highly detrimental to aquatic and other ecosystem. The present study was chosen to know the level of organochlorines contamination in ground water of Thiruvallur district, Tamil Nadu, India. The samples were highly contaminated with DDT, HCH, endosulfan and their derivatives. Among the HCH derivatives, Gamma HCH residues was found maximum of 9.8 μg/l in Arumbakkam open wells. Concentrations of pp-DDT and op-DDT were 14.3 μg/l and 0.8 μg/l. The maximum residue (15.9 μg/l) of endosulfan sulfate was recorded in Kandigai village bore well. The study showed that the ground water samples were highly contaminated with organochlorine residues.     

Pesticide residue level in tea ecosystems of Hill and Dooars regions of West Bengal, India

In the present study we quantified the residues of organophosphorus (e.g. ethion and chlorpyrifos), organochlorine (e.g. heptachlor, dicofol, alpha-endosulfan, beta-endosulfan, endosulfan sulfate) and synthetic pyrethroid (e.g. cypermethrin and deltamethrin) pesticides in made tea, fresh tea leaves, soils and water bodies from selected tea gardens in the Dooars and Hill regions of West Bengal, India during April and November, 2006. The organophosphorus (OP) pesticide residues were detected in 100% substrate samples of made tea, fresh tea leaves and soil in the Dooars region. In the Hill region, 20% to 40% of the substrate samples contained residues of organophosphorus (OP) pesticides. The organochlorine (OC) pesticide residues were detected in 33% to 100% of the substrate samples, excluding the water bodies in the Dooars region and 0% to 40% in the Hill region. The estimated mean totals of studied pesticides were higher in fresh tea leaves than in made tea and soils. The synthetic pyrethroid (SP) pesticide residues could not be detected in the soils of both the regions and in the water bodies of the Dooars. Sixteen percent and 20% of the made tea samples exceeded the MRL level of chlorpyrifos in Dooars and Hill regions respectively. The residues of heptachlor exceeded the MRL in 33% (April) and 100% (November) in the Dooars and 40% (April) and 20% (November) in the Hill region. Based on the study it was revealed that the residues of banned items like heptachlor and chlorpyrifos in made tea may pose health hazards to the consumers.     

Organochlorine pesticide residues in Songkla Lake

The water quality of Songkla Lake for organochlorine (OC) pesticide contamination was studied from chosen sampling sites (stations) using the lakes geographic data and pollution sources. The water samples were collected monthly from 13 stations in Songkla Lake during September 1991–November 1992. The OC pesticide residues found were Heptachlor, Heptachlor Epoxide, DDD, DDE, DDT and Aldrin in the range 0–0.5690 ppm. This study showed that DDT and its metabolite products (DDD and DDE) dominated OC pesticide residues in the lake. The concentration of OC residues also depended on the season, i.e. at some sampling stations the concentration of OC residues in the dry season (July–September) were higher than in the wet season (October–January).     

Pesticides residues in okra (non-target crop) grown close to a watermelon farm in Ghana

The study looked at the levels of pesticides in okra grown close to a watermelon farm herein referred to as a non-target crop. The watermelon received some pesticide application in the course of its cultivation, and the okra which was not meant to be sprayed was also affected by the pesticide. About 500 okra samples were collected for a period of 6 weeks and pesticides extracted with 1:1 n-hexane and dichloromethane which was analysed with Agilent 2222 GC/MS coupled with 389 auto-sampler. The results confirmed accumulation of significant levels of pesticides in the non-target crop (okra grown close to watermelon farm). Levels of organochlorine pesticides ranged from 3.10 to 7.60 μg/kg whilst the organophosphorus pesticides had levels ranging from 2.80 to 2016.80 μg/kg. The synthetic pyrethroid pesticide mean levels also ranged from 0.10 to 4.10 μg/kg and were below World Health Organization/Food and Agriculture Organization-recommended residue levels, and though not appearing to constitute a grave threat to life, their occurrence is a concern, and pre-emptive techniques must be developed to thwart the contaminations. Though the non- target crop was not treated directly with the pesticides, some level of contamination with organochlorine and organophosphorus pesticides persisted in the crops. It can be inferred that application of pesticides affected the adjoining crops, meaning that inter-cropping and mix-cropping might not be acceptable when one of the crops requires pesticide application. It is important for the farmers to be trained to ensure proper application of pesticide to minimise its impact on the health of consumers.     

Riverine pollution in some northern and north eastern states of india

Water samples from 30 rivers in northern and north-eastern hilly states of India were analysed for bacteriological and physicochemical parameters along with metals and pesticide residues. It was found that 34% of samples had >50 coliforms/100 ml, while 24% of samples demonstrated >50 thermotolerant (faecal) coliforms/100 ml. Among the metals, iron was found to be above maximum permissible limits in the rivers of all the states, while manganese was found to be above the maximum permissible limit in the rivers of Tripura and some northern states. Zinc, lead, nickel, chromium, copper, cobalt and cadmium plus physicochemical parameters and residual pesticides, however, were within their maximum permissible limits.     

我国农田农药流失现状及减控策略

农业面源污染已经成为全球水污染的主要来源,其中具有生物毒性的农药污染物对人体健康和生态环境安全构成了严重威胁。分析了我国农田农药流失现状,指出流失的主要农药品种与用药历史和特点密切相关,水体中检出的有机氯农药主要源于早期农药残留,检出的有机磷农药和长残效除草剂部分种类目前仍在使用。提出从影响农药流失的各个环节入手,制定严密的减控策略。植物缓冲带是拦截农药流失的常用措施,可以实现对农业面源污染的可持续治理。建议实行生态功能区划,严格限制高毒农药的施用,减少化学农药施用量,规范农药喷洒器械和施药技术,从源头上控制农药流失,从而降低农业非点源污染带来的危险。     

Determination of some organochlorine pesticide residues in honeys from Konya, Turkey

In this study, 24 organochlorine pesticide residues in 109 different honey samples collected from stores and open markets in Konya, Turkey were analyzed by gas chromatography-electron capture detection. Aldrin, cis-chlordane, trans-chlordane, oxy-chlordane, 2,4^′ -DDE, and 4,4^′ -DDE were found in all honey samples. The mean value was 0.0540 μg g^???1 for oxy-chlordane. In the 55 samples of 109, levels of organochlorine pesticide residues of oxy-chlordane were determined as higher than those of Turkish Alimentarius Codex maximum residual limits (MRLs). Other organochlorine pesticide residues also exceeded MRLs except for cis-heptachlor epoxide and α-hexachlorocyclohexane. Since all of the honey samples are found contaminated and most of these samples exceeded MRLs, a control of organochlorine pesticide residues in honey is necessary for consumer health.     

Persistent Organochlorine Pesticide Residues in Soil and Surface Water of Northern Indo-Gangetic Alluvial Plains

This study reports the concentration levels and distribution pattern of the organochlorine pesticide (OCPs) residues in the soil and surface water samples collected from the northern Indo-Gangetic alluvial plains. A total of 31 soil and 23 surface water samples were collected from the study region in Unnao district covering an area of 2150 km² and analyzed for aldrin, dieldrin, endrin, HCB, HCH isomers, DDT isomers/metabolites, endosulfan isomers (α and β), endosulfan sulfate, heptachlor and its metabolites, α-chlordane, γ-chlordane and methoxychlor. In both the soil and surface water samples β- and δ-isomers of HCH were detected most frequently, whereas, methoxychlor was the least detected pesticide. The results showed contamination of soil and surface water of the region with several persistent organic pesticides. The total OCPs level ranged from 0.36–104.50 ng g^–1 and 2.63–3.72 μg L^–1 in soil and surface water samples, respectively.     

Ground water contamination by organochlorine insecticide residues in a rural area in the indo-gangetic plain

Residues of several organochlorine insecticides were monitored in the ground water from a rural area near Farrukhabad in the vicinity of the Ganga River in northern India for one year (1991–1992). Almost all the samples were found to be contaminated with residues of Hexachlorocyclohexane (HCH) and Dichloro-diphenyl-trichloroethane (DDT). Residues of Aldrin, endosulfan and heptachlor were also detected in a large number of samples. The concentrations of aldrin residues greatly exceeded the WHO guideline value for drinking water, concentrations of heptachlor and DDT residues also occasionally exceeded the specified limits. Migration of pollutants through ground water recharge with polluted Ganga River water and monsoon rains carrying undergraded residues downwards from the soil surface are throught to be important sources of insecticide contamination of ground water in the region.     

Effectiveness of wastewater management in rural areas of developing countries: a case of Al-Chouf Caza in Lebanon

Ghaggar, one of the major rivers of northern India originating in outer Himalayas and flowing through the state of Punjab, Haryana, and Rajasthan, is put to multiple uses. Along its course of 464 km, it receives discharge from various cities and runoff from agricultural lands. Punjab and Haryana are two predominantly agricultural states of India using substantial amounts of agrochemicals, yet there are no reports available in literature on the level of pesticides in the stretch of river Ghaggar through Punjab and Haryana. This is the first report on pesticide pollution of the river Ghaggar in Haryana. Water samples along the 230-km stretch of the river in Haryana were analyzed for the presence of organochlorine insecticide residues. While aldrin and dieldrin were below detection limits, both hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) were traceable in all the water samples. High concentration of β-HCH among ΣHCH indicates old pollution source whereas predominance of p,p^′ -DDT among ΣDDT reflects its recent use in the catchment area of the river. The concentrations of HCH and DDT in all the samples were above the permissible limits prescribed by the European Commission Directive for drinking purposes.     

The Contamination Levels of Organochlorine Pesticides in Water and Sediment Samples in Uluabat Lake, Turkey

The Uluabat Lake is a reservoir of 125 km² surface area, in the boundaries of Bursa province, Turkey. The results showed that Uluabat Lake was still contaminated by organochlorine pesticides and their residues despite the existence of bans over a long time. Considerable amounts of organochlorine pesticides (HCB, p.p^′-DDT, p.p^′- DDE, α -, β- and γ-BHC, Aldrin, Heptachlor epoxide, Endrin, Endosulfan I and II) were detected in water and sediment samples during one-year study in this lake. Samples of water and sediment were collected in different regions, (6 sampling point) of the lake between February 2002 and November 2002.The mean levels of organochlorine pesticides in water and sediments were determined. According to results, it was found that various environs in Uluabat Lake were contaminated by 11 different organochlorine pesticides. Residue analyses showed that higher organochlorine pesticides and their residues were generally more accumulated in the sediment samples.     

Prevalence of certain inorganic constituents in groundwater samples of Erode district, Tamilnadu, India, with special emphasis on fluoride, fluorosis and its remedial measures

A total of 60 drinking water samples collected from Erode district, Tamilnadu, India were analysed for fluoride contamination, besides water quality parameters such as pH, electrical conductivity, total dissolved solids, total alkalinity, total hardness, fluoride, bicarbonates, calcium, magnesium, nitrate, sulphate, phosphate, sodium and potassium. The results obtained were found to exceed the permissible limits. The concentration of fluoride in the water samples ranged between 0.5 and 8.2 mg/l and revealed that 80% of the water samples contain fluoride above the maximum permissible limit. Similarly, the concentrations of nitrate, hardness, calcium and magnesium in some samples were also more than the permissible level. Pearson’s correlation coefficient among the parameters showed a positive correlation of fluoride with total hardness and calcium. It is inferred from the study that these water sources can be used for potable purpose only after prior treatment.     

加速溶剂萃取-凝胶净化色谱-气相色谱质谱法测定农用地土壤中有机氯农药方法研究

通过对加速溶剂萃取、平行蒸发及净化方法等环节的优化实验,建立了加速溶剂萃取-凝胶净化色谱-气相色谱质谱法测定农用地土壤中23种有机氯农药的检测方法。结果表明,方法检出限为0.0034~0.0052 mg/kg;对化合物质量分数为0.25 mg/kg的土壤加标样品进行平行实验,回收率为82.0%~93.7%;测定结果的相对标准偏差（RSD）≤8.7%。对土壤有证标准质控样品进行分析,测定结果均在验收范围之内。该方法准确可靠,灵敏度较高,样品净化效果较好,能够满足农用地土壤中有机氯农药残留痕量分析的要求。     

Analysis of pesticide residues in Peninsular Malaysian waterways

The use of organochlorine pesticides has caused concern due to their effects on human health and the Malaysian aquatic ecosystem, particularly so in view of their persistent and bioaccumulative properties. Since the extent of organochlorine pesticide pollution in Malaysian waterways is unknown except for isolated instances, a systematic survey has now been carried out. Water samples from various rivers were extracted, cleaned up with Florisil and analysed for the individual organochlorine pesticides by gas chromatography (GC) with an electron capture detector (ECD). DDE, DDT and heptachlor were present in all the river water samples of the west coast of Peninsular Malaysia. Other organochlorine pesticides were also identified from the water samples. However, the levels of all these are still below criteria values for Malaysian aquatic life, indicating that organochlorine pesticide pollution is less of a problem than other organic or inorganic pollutants.     

Monitoring of pesticide residues levels in fresh vegetable form Heibei Province,North China

In this study, 226 samples of seven types of domestic vegetables collected from several vegetable-growing regions in Hebei Province of China were tested for the presence of 38 different agricultural pesticides using a gas chromatograph equipped with electron capture and nitrogen phosphorus detectors. The aim of this study was to investigate the distribution of pesticides in main vegetables from Hebei Province. Results showed that, in 65.93 % of the samples, no residues were found, 31.42 % of the samples contained pesticide residues at or below the maximum residue levels (MRLs), and 2.65 % of the samples contained pesticide residues above MRL. The most frequently detected pesticides were acephate (31), followed by cyhalothrin (15), bifenthrin (8), omethoate (6), isazophos (6), dimethoate (5), chlorpyrifos (2), and malathion (1). Some (1.33 %) of the samples contained multiple residues. The results provide useful information on the current contamination status of a key agricultural area in North China, and points to the continuous monitoring and strict regulation of pesticide use on vegetables are necessary.     

Pesticide residues in rain water from Hisar, India

Presence of pesticide residues was studied in rain water during 2002 employing multi residue analysis method by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns. The presence of pesticide residues in surface aquatic system triggered the investigation of the presence of pesticides in rain water. A total of 13 pesticides were detected in rain water samples. Among the different groups of pesticides, organochlorines were present in the range of 0.041–7.060 ppb with maximum concentration of p,p’-DDT up to 7.060 μg l⁻¹. Synthetic pyrethroids were present ranging from 0.100 to 1.000 μg l⁻¹ and organophosphates in the range of 0.050–4.000 μg l⁻¹ showing maximum contamination with cypermethrin (1.000 μg l⁻¹) and monocrotophos (4.000 μg l⁻¹) of the respective groups. Almost 80% samples showed the residues above MRL of 0.5 ppb fixed for multi residues and on the basis of single pesticide, 16–50% samples contained residues above the MRL value of 0.1 ppb.     

Groundwater quality and hydrogeochemical properties of Torbalı Region, Izmir, Turkey

The large demand for drinking, irrigation and industrial water in the region of Torbali (Izmir, Turkey) is supplied from groundwater sources. Almost every factory and farm has private wells that are drilled without permission. These cause the depletion of groundwater and limiting the usage of groundwater. This study investigates spatial and temporal change in groundwater quality, relationships between quality parameters, and sources of contamination in Torbali region. For this purpose, samples were collected from 10 different sampling points chosen according to their geological and hydrogeological properties and location relative to factories, between October 2001 and July 2002. Various physical (pH, temperature, EC), chemical (calcium, magnesium, potassium, sodium, chloride, alkalinity, copper, chromium, cadmium, lead, zinc) and organic (nitrate, nitrite, ammonia, COD and cyanide) parameters were monitored. It was observed that the groundwater has bicarbonate alkalinity. Agricultural contamination was determined in the region, especially during the summer. Nitrite and ammonia concentrations were found to be above drinking water standard. Organic matter contamination was also investigated in the study area. COD concentrations were higher than the permissible limits during the summer months of the monitoring period.