Effect of Soil Arsenic on Soil Microbial Populations in West Bengal, India

Original Research Article Arsenic, predominantly of geogenic source, has contaminated ground water and soil of the West Bengal, covering 111 blocks under 12 districts. Arsenic ingestion causes terrible health hazards to human being. Reported groundwater as content of 50 – 1600 μg/L, is several times more than permissible limit. Arsenite (III) binds to proteins and Arsenate (V) affects energy production in biological cells which results in skin melanosis to cancer. Microbes populations are indicators of soil health, influences soil fertility and may also offer possibilities of alleviation. Influence of as toxicity and tolerance in different soil microbes needs to be studied. Microorganisms are capable to use arsenate (V) or arsenite (III), in their metabolism through their ars genetic system. The present investigation involves enumeration of bacteria, actinomycetes and fungi in the affected areas of Nadia District. Soil samples were collected from 21 zones. The present study was showed how the microbial population varies in different arsenic contaminated area. The samples were analysed in a Parkin Elmer Atomic Absorption Spectrometer with Flow Injection Analysis system (FIAS 400). The data was analysed in using standard statistical tools. The total arsenic loading in the sample soils ranged between 0 to 20.00 mg kg -1 ; bacterial population varied from 44x10 -8 to 203x10 -8 , and actinomycetes from 10 x10 5 to 61 x10 5 and fungi from 4x10 5 to46x10 5 CFU per gram soil. Total soil As content and microbe populations were highly significant with bacteria -0.802 **, actinomycetes --0.763 ** and fungi -0.732 ** .