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IntroductionPollution of natural waters with waste effluentsarising from various industries has become a seriousproblem in India.In Rajasthan particularly,textilemills represent an important economic sector.Effluents from these textile and other dye-relat…  相似文献   
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In this study, nerve conduction, organochlorine (OC) pesticide residues in blood and cholinesterase activity levels of pesticide sprayers employed in mango plantations at Lucknow, North India, were determined. Fifty-two sprayers from mango plantations who regularly spray mixture of pesticides like organophosphates (OP), OCs, and carbamates were considered as exposed group. Eighteen subjects with similar socio-economic status of exposed group, who do not handle pesticides, were selected as controls. Questionnaire-based interviews related to personal and occupational histories of the study subjects were carried out. Sprayers did not use any personal protective equipment during pesticide handling. The blood-pesticide analyses of sprayers show higher mean values of hexachlorohexane (HCH), γ-HCH, δ-HCH, total HCH, op-DDT compared with the controls. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activites were significantly reduced among sprayers. Risk of motor nerve conduction deficits was observed in sprayers with low AChE activity. Negative correlation of motor and sensory nerve conduction deficits was observed with the duration of exposure and age among sprayers. The study demonstrated that the prolonged exposure to mixture of pesticides, ergonomic factors, decline in cholinesterase activity may lead to nerve conduction dysfunction. The findings suggest the need for controlled use of pesticides in the plantation and indicated the need for training and implementation of hygiene practices like proper usage of personal protective equipments.  相似文献   
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Samples from three cultivated soils and one from a roadside, all in Ontario, were found to contain less than 1 to 68 ppb of 1,2-Benzanthracene (BA). Two plots subjected to stubble (residue of wheat crop) burning annually for 15 years did not contain significant amounts of BA, although polyaromatic hydrocarbons, including BA, result from pyrolysis of most organic matter.  相似文献   
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In February 1972 the Nixon Administration proposed a tax on sulfur oxide emissions, beyond the Federal standards, of electric power plants. It was hoped that such a tax would discourage power plant locations in heavily polluted areas like urban areas. Assuming that such a tax varies over space because pollution is not invariant over space, the spatial theory of the firm is presented in this paper cast doubt on the efficacy of such a polltuion tax to achieve the desired goal of the administration. In particular it is shown that the cost-minimizing spatial firm would abate its pollution in response to a tax by either changing its location or by reducing waste through process change or by using a transportable abatement good if the tax savings due to the change in marginal abatement through location change per unit change in abatement is greater than or equal to transport rate on the abatement good. If the goal of the firm is to maximize profits, the desired outcome would follow if in addition to the fulfillment of the above condition the percentage change in the delivered price of raw material (situated at one end of the linear location space) per unit distance is greater than or equal to the percentage change in net marginal revenue, i.e., marginal revenue net of transport cost per unit of output. In simple terms, the conclusions of this paper raise doubts regarding the effectiveness of a pollution tax in curtailing pollution of a firm which is operating in a space economy. This outcome is peculiar to a spatial firm. Sufficient conditions also have been obtained when land input is included in the production function of the firm.  相似文献   
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Investigations on geohydrological aspects of coastal aquifer are important in order to understand the mechanism of ground water salinisation. The present study describes the salinity variations of ground water in deep boreholes drilled in Charnockite rock formation of Kalpakkam, on the eastern coast of India. Water samples collected up to 600m depth were analyzed for salinity variation. It is noticed that in one of the boreholes, (borehole K1), the salinity level is found to be 74 parts per thousand (ppt) at 400 m depth. Influence of surface saline water bodies viz., sea (26-28.5 ppt), backwaters (27-30 pt) and Buckingham canal (27-32 ppt) as the possible sources of recharge of fresh waters through joint and fracture system of the rock are discussed in this paper. Studies would assist in understanding the geohydrological characteristics of deep geological formation.  相似文献   
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