Fresh evidence has emerged about prevalence of endosulfan residues in the groundwater of Kasaragod district and recent use of the pesticide in the area.

A study by P.S. Akhil and C.H. Sujatha of the Department of Chemical Oceanography of Cochin University of Science and Technology (Cusat) reported that organochlorine insecticides, particularly high concentrations of endosulfan and BHC (hexachlorobenzene), were persisting in the environment. This was despite restrictions on use of BHC, and ban imposed by the High Court and the government on use of endosulfan. The pesticide residues which remained in the soil from earlier application become the source of pollution of water bodies through land runoff, leaching and ultimately contaminate drinking water sources.