Biman Gati Gupta

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Chatta Canal and Churial Canal are under severe pollution stress due to the discharges of huge quantity of effluent from more than 800 tiny and small scale (SSI) textile bleaching, dyeing and printing units located at Maheshtala Region (22.29 0 N, 88.11 0 E), South 24-Parganas, West Bengal. In the past, the canal was a source of fishing and feeding water to the adjoining land for irrigation. The canal now carries exclusively industrial effluents and sewage except in rainy season and hence poses severe threat to agri-irrigation. Surface water samples were collected from various locations of Chatta canal during summer, rainy and winter season for two years (2012-13) for assessment of water quality following standard analytical methods. The study revealed that the chemical parameters like COD (552mg/l), suspended solids (540mg/l), total dissolve solids (3398 mg/l), biological oxygen demand (172 mg/l), carbonate (711mg/l), Chromium (0.10mg/l) and Lead (0.027 mg/l) exceeded the maximum permissible discharge limits laid down by Bureau of Indian Standards (BIS) and WHO (2003) standards. Hence, a comprehensive eco-planning is urgently required to reduce contamination of agricultural fields as well as crops, fruits and vegetables grown for human consumption.

The environmental exposure to heavy metals is a well-known risk factor for several gastrointestinal (GI) disorders. The present study was conducted at Maheshtala textile, bleaching dyeing industrial area for two consecutive years (2012–2013) to study the impact of bleaching and dyeing effluent discharge on accumulation of heavy metals in canal water, soil, fruits, and vegetable as a part of environment management of the area and ecological planning. During experiment, we investigated the levels of heavy metals (Pb, Zn, Ni) in effluent of small bleaching and dyeing units in soil, fruits, and vegetable samples of Maheshtala region of South 24-Pargana district of West Bengal, India, where gastrointestinal disorders have become an epidemic dimension among the people inhabiting that area. Heavy metals contents of the samples were determined by atomic absorption spectrophotometer. Three heavy metals (Pb, Cd, and Ni) were present in 2–40 fold higher concentrations whereas zinc level was present in 50 fold lower concentrations in vegetable and fruits. The higher concentrations of heavy metals in aquaphytes, vegetables, and fruit samples tested were found to be strongly correlated with the concentrations of metals present in soil or water matrix contaminated with effluents of bleaching and dyeing industries. The soil, fruits, and vegetable samples contained potentially toxic heavy metals in such high levels that these elements could be related to higher prevalence and/or vulnerability of GI disorder, ulcer, and cancer risks in Maheshtala region under study.