WHO agency confirms insecticide caused cancer

The International Agency for Research on Cancer (IARC), the specialised cancer agency of the World Health Organization said that a common insecticide causes cancer.

The agency reached the conclusion after evaluation of the carcinogenicity of the anti-lice insecticides Lindane and pesticide DDT and the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D).

The WHO said in a statement yesterday, after a review of the latest available scientific literature, a working group of 26 experts from 13 countries convened by the IARC Monographs Programme classified the Lindane as carcinogenic to humans (Group 1).

The WHO said sufficient evidence existed that showed the carcinogenicity of lindane for non-Hodgkin lymphoma (NHL) in humans. The insecticide DDT was classified as probably carcinogenic to humans (Group 2A), on the basis of sufficient evidence that it caused cancer in experimental animals while there was limited evidence of its carcinogenicity in humans.

Epidemiological studies had also shown associations between exposure to DDT and NHL, testicular cancer, and liver cancer and there was also strong experimental evidence that DDT could suppress the immune system and disrupt sex hormones.

However, overall, no association was shown between breast cancer and DDT levels measured in samples of blood or fat.

Meanwhile, experts warned that the findings of the specialist panel of the World Health Organisation (WHO) that Lindane could cause cancer was a warning to Indian consumers who might be still using anti-lice shampoo containing Lindane.

Until restrictions were placed on the use of Lindane in  India three years back, it was also used for agricultural purposes and as a substitute for DDT, according to C Jayakumar, Steering Committee member of the International POPs Elimination Network. POPs is an acronym for persistent organic pollutants.

Though it had been banned in the country, Lindane might be an ingredient in many anti-lice shampoos available in the market. He added, the findings of the International Agency for Research on Cancer (IARC) under the WHO found that Lindane could cause cancer was a cause of grave concern.

The agency report, released on Wednesday, also pointed out that it was an ingredient in some head lice and scabies treatments in some developing countries including India.

The findings of the agency were largely based on studies among agricultural workers, and the  research found ''a consistent, approximately 50 per cent increase in risk, with higher risks in heavily exposed exposed agricultural workers.''

Though the agricultural use of Lindane was restricted in India after other countries including the US and the EU banned it, its use was allowed for 'medicinal purposes,' according to C Jayakumar, who is also the director of Thanal, a Thiruvananthapuram-based NGO.