CHEMICAL ANALYSIS OF WATER SAMPLES FROM KUTTANAD WETLAND ECOSYSTEM FOR PERSISTENCE OF PYRETHROID PESTICIDE RESIDUES: LAMBDA CYHALOTHRIN, FENVALERATE AND CYPERMETHRIN

Kuttanad wetland is popularly considered as the “rice bowl of Kerala” where the history of paddy cultivation can be traced back to centuries. A preliminary survey revealed that various types of pyrethroid pesticides are extensively applied in Kuttanad. Lambda cyhalothrin, Fenvalerate and Cypermethrin are some of them. 5 sampling stations were selected from the rural regions of kuttanad .Two crop periods (Virippu and Puncha periods of agricultural activities) and Monsoon season were selected for the study. The water samples were collected between 7 am and 10 am The selected samples were analysed using Gas Chromatography Mass Spectrometry (GCMS). The Monsoon season and the comparatively less active cropping Virippu period followed, showed absence of residues in the surface water except for Cypermethrin. These results are suggestive of insufficiency in natural processes that degrade the pesticides released into the system due to the enormous dumping of different types of chemicals.