Quantification of benzene in groundwater sources and risk analysis in a popular South Indian Pilgrimage City – A GIS based approach

Abstract The present research work quantified the concentration of benzene in a total of hundred groundwater samples at the proximity of petrol bunks and residential places in Madurai District. The average values recorded in Jan 2011, Feb 2011 and Mar 2011 were 0.100 mg L −1 (10 times of PL), 0.138 mg L −1 (14 times of PL) and 0.060 mg L −1 (6 times of PL) respectively. A significant variation in the benzene level during February–March 2011 was validated through Student’s t -test analysis. Hierarchical cluster analysis using dendograms revealed the un-symmetric distribution of benzene during the study period. The cancer risk analysis at corporate locations among children was seven folds higher as compared to the risk of adults. The benzene concentration levels are interpreted using Arc Geographical Information System (Arc GIS) through thematic maps.