Journal of Environment and Sociobiology

Debasis Ghosh ¹, Mrinal Mandal ², Monali Banerjee ²

Affiliations
1 Department of Geography, University of Calcutta, West Bengal, IN
2 Department of Geography, Sidho-Kanho-Birsha University, Purulia, West Bengal, IN

Abstract

Fluoride contamination in drinking water is a burning environmental issue of the World today. The people of nearly 29 countries are affected with 'fluorosis' due to intake of fluoride-rich water including India. In West Bengal, excess fluoride in groundwater has been found in seven districts. Those are Purulia, Birbhum, Bardhaman, Bankura, Malda, South Dinajpur and North Dinajpur. Fluorine is a common element that does not occur in the elemental state in nature because of its high reactivity. It exists in the form of fluorides in a number of minerals. High fluoride is derived from fluoride rich minerals, such as, apatite, fluorite, hornblende and biotite which are present in the country rocks dominated by granite gneisses and hornblende-biotite gneiss. It is observed that the sub-surface geo-hydrological environment of Purulia is contaminated with fluoride. Intensive and prolonged semi-arid climate, long term withdrawal of groundwater for irrigation, alkaline nature of sub-surface circulating water, long residence time of water in fractured aquifers and geological structure are the favourable conditions for fluoride enrichment (2%-10%) in the Purulia region. Geological set up of Purulia plays a major role for availability of ground water as well as the quality of water. In Raghunathpur-I, Purulia II and Arsha Blocks of Purulia district, fluoride concentration is higher than permissible limit in ground water. Water samples were collected from 25 different tube wells under Purulia Block-II and Raghunathpur-II in Purulia district. Sampling bottles were labelled, tightly packed, transported to the laboratory and stored at 4°C for chemical analysis, such as, total dissolved solid (TDS), total hardness (TH), total alkalinity (TA), Calcium (Ca²+), Magnesium (Mg²+), total Iron (Fe) fluoride (F^-). Data were also collected from Natural Resources Data Management System (NRDMS) department of West Bengal. The present work peeps into the negative effect of fluoride on the human health of fluoride affected Blocks of the study area.

Keywords

Country Rocks, Geological Structure, Genesis, Contamination, Fluoride.

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