Pesticide residue induced blemished water bodies in the riparian tributaries of Chalakkudy River

Abstract

Agricultural, industrial, and techno-socio-cultural intervention by man had an influence on the quality of the river water and its tributaries. Contemporary agriculture practices reveal and augment the use of pesticides to meet the food security and to satisfy the needs of surging population which results in contamination of the aquatic environment. In the pursuit to achieve maximum crop production, pesticide use has played a major role and has resulted in the accumulation of pesticide residues deemed to be highly detrimental to aquatic and related ecosystem. This study funded by Kerala State Council for Science, Technology and Environment was aimed at understanding the extent of pesticidal residues and pollution of water bodies in the riparian tributaries of Chalakkudy river. The efforts to assess the quality of water in the Chalakkudy tributaries confirmed the presence of pesticide residues of quinalphos and ethion (0.21-2.90 µgL-1) through chemical analysis in 41.18% of total number of water samples. Pesticide residues of ethion constituted 71.42% of the water sample inveterate for pesticide residues. When pesticide residues of quinalphos (4.80 µgL-1) and ethion (1.80 µgL-1) were detected in the middle reaches of Chalakkudy river, in the upper reaches it was ethion that was detected at maximum level (2.20 µgL-1) near to Kerala Sholayar dam. Results suggest that the continuous presence of pesticide residues of ethion and quinalphos can contaminate other nearby surface water bodies or even ground water that can masquerade critical health threats to the health of local residents of this area.