There are significant differences in the water chemistry of the Himalayan and southern peninsular rivers. Large and small rivers also show different types of water quality. Liquid and solid waste definitely contribute to water quality in urban centres such as Delhi and even coastal regions, as near Mumbai, are affected by waste discharges. The sub-continent also suffers from problems associated with floride and also arsenic in different parts. Even drinking water shows contamination with metals and POP. Thus over one billion people, both qualitatively and quantitatively, are at water risk.
Water quality studies in such aspects as POP, heavy metals and microbiology are urgently needed - particularly in regions such as Nepal and Bhutan where data base is scanty. The intensive agricultural activity in the sub- continent is reflected in enhanced levels of nutrients in various water bodies in many parts of the region. Thus, water in south Asia may be thought no longer to represent natural water quality but shows impact of different types of human activities practically in every part of the sub-continent.
Keywords: Water quality, south Asia, metals, POP