Evaluation of groundwater quality and its impacts on child health

摘要

Groundwater is the major source of drinking water supply in all sub-urban areas. The physical, chemical and biological characteristics of groundwater play a major role in the health of the people. Spatial and temporal analysis of the groundwater quality has been done for shallow and deep wells in Pallikaranai, Kancheepuram district, Tamil Nadu, India. Three zones have been identified in the study area based on the distribution of electrical conductivity. Sixteen representative wells have been selected for continuous monitoring of both chemical and microbiological parameters from December 2009 to December 2010. Ninety five per cent of the analysed well shows that the groundwater is unhealthy for drinking purpose also the quality were gradually degraded towards the marsh in the eastern and northern part of the study area. TDS and CI- exceeds the recommended limits of BIS and WHO whereas nitrite and nitrate are within the permissible limits. The range, mean and standard deviation values revealed considerable variations in the water samples with respect to their chemical composition. Statistically significant correlations between turbidity, ammonia nitrogen total coliform and E. coli which illustrate that the chemical parameter influences the abundance of coliforms. The prevalence of pathogenic organism such as vibrio is high in zone 2 during pre and post monsoon. In zone 3 Vibrio sp. were not observed during pre monsoon whereas it was observed in post monsoon, the highest rates of diarrheal cases were detected in the north eastern part of the study area.