A pesticide is causing wide-spread cancer, impotency, thyroid deficiency and premature puberty in parts of North Kerala and Karnataka, health Minister Dr C P Thakur told the Pioneer on Thursday. Dr Thakur said that a study conducted by the Indian Council of Medical Research (ICMR) has shown that the spread of Indo Sulphane pesticide on cashew plantation in the two states, has had dangerous fallout on a large population.