Abstract
Heavy metals in water have severe toxicity towards aquatic life and human beings. In north-eastern region of India, increasing rate of heavy metal content in drinking water has become a matter of serious concern as it has adverse health affects at high concentration. Many researchers have already studied high concentration of arsenic and heavy metals in different districts in this region. In Lakhimpur district of Assam in India, no detailed study about arsenic and heavy metals in drinking water has been done till now. In order to assess the concentration of heavy metals in drinking water of Lakhimpur district of Assam, twenty locations were selected for the study. The analysis was carried out for three years from June 2005 to May 2008 covering four seasons in a year. Metals studied in the present investigation were Zn, Pb, Ni, Cu and As. From the analytical data, it was found that Cu and Zn concentration was within ISI permissible limit. The all season average values of Ni in all the sampling points were found within 0.1mg/L. Pb concentration was found to be at a higher level in almost all the sources. In 5% samples As content exceeded ISI limit of 0.05mg/L. Seasonal variations were also observed and high values were detected in monsoon season. Health survey in the district were also done with the help of a pre-prepared questionnaire and the over all health status was found to be not satisfactory. Most of the people in the district suffered from mild to severe gastrointestinal diseases. Though, arsenic concentration was high in a few locations, no case of arsenocosis has been reported till date.