Microbiological status of drinking water sources and its relationship with human health in Solan, India

In Solan district, the developmental activities associated with chemical based farming, rapid urbanization, and rampant industrialization have led to many diarrhoeal, gastroenteritis, and hepatitis disease outbreaks. This has necessitated for microbiological assessment of indicator organisms, the thermotolerant coliforms, in drinking water sources, and their relationship with diarrhoeal disease. All the 49 Public Health Institutes (PHIs) of the district were categorized into very low, low, moderate, and high disease burden regions by stratification method. For drinking water, 55.5, 16.5, and 17% people preferred springs, borewells, and hand-pump respectively. These sources inventoried by Knowledge, Attitude, and Practice survey in one of very low and seven of high disease burden regions, and were analyzed by multiple tube fermentation technique. A cross-sectional survey of 200 children was undertaken for diarrhoeal disease estimation. Parwanoo, an industrial and Kurgal, a non industrial region witnessed highest (30.20) and lowest (4.40) Most Probable Number (MPN) per 100 ml water of thermotolerant coliforms, respectively. Thermotolerant coliforms were also observed significantly more (16.77 MPN/100 ml water) in monsoon than in post monsoon season (9.04 MPN per 100 ml water). The thermotolerant coliform Escherichia coli was recovered from six and three water sources respectively during monsoon and post monsoon. A strong correlation (r = 0.78) existed between the diarrhoeal disease occurrence and the concentration of thermotolerant coliforms in monsoon whereas it was moderate (r = 0.61) in post monsoon. The study indicated more contamination of water sources due to industrial activities which further got aggravated during the rainy season of the region.