The National Poisons Information Centre (NPIC) functioning at the All India Institute of Medical Sciences (AIIMS), New Delhi has revealed that 34.13per cent of poison cases that were reported to the centre during a period of three years (1999-2002) were caused by fast moving insect repellents like All-Out, Good Knight and Lakshman Rekha. These products were found to contain synthetic pyrethroids like d-allethrin, prallethrin and deltamethrin, which were the major causes of poisoning. The NPIC observation is based on a total of 2719 cases it attended during the period.
The NPIC observed that there has been an increasing trend to use pyrethroids over the last few years because of their less toxicity and flooding of market with new products. The queries received by NPIC were categorized into two, household and agricultural pesticides. Poisoning due to household insecticides was as high as 68per cent when compared to the pesticide poisoning.
According to Dr SK Gupta, chief NPIC, the household poisoning was mainly due to synthetic pyrethroids to be followed by rodenticides (28.5per cent), organophosphates (13.36per cent), carbamates (10.15per cent) and parad (13.84per cent). Rodenticides included zinc phosphide, barium carbonate and superwarfarins. Poisoning due to organophosphates and carbamates showed a downward trend when compared to NPIC's previous study, he said.
An important observation is the rise in the number of poisoning cases due to a grain insecticide marketed as "Parad" containing elemental mercury, which is commonly used in households, he added.
The data studied indicated that it was largely the improper storage of pesticides, which caused poisoning both in households as well as in fields. "The public needs to be thoroughly educated about the risks of various chemicals and their proper storage both in fields as well as in homes which could decrease poisoning incidence to a great extent", Dr Gupta suggested.
The NPIC also highlighted a study conducted by Indian Council of Medical Research on the amount of pesticide residues in food. The ICMR study had found that the milk samples contained 28per cent HCH and 37per cent DDT above the tolerance level. NPIC felt that lack of stringent laws to maintain quality standards in food products is a matter of concern. The required coordination is lacking between various ministries like Ministry of Chemicals and Fertilizers, Health and Family Welfare, Environment and Forests and Consumer Affairs and Food and hence the quality standards for food products are poor. The result is the presence of alarmingly high levels of pesticides in almost all the food items available in our country, Dr Gupta observed.
According to NPIC, the major pesticides associated with high health risks are Alachlor (herbicides - carcinogenic and mutagenic potential), Carbaryl (carbamates - neurotoxic, mutagenic and carcinogenic effects), Chlopyrifos (organophosphates - affects nervous system and respiratory system), DDT (chlorinated hydrocarbons - carcinogenic, affects developing foetus, liver and kidney, testicular and breast cancer, birth defects), Methyl Parathoin Monocrotophos (organophosphates - neurotoxic, risk to children, affects nervous system and respiratory system), 2,4-D (chlophenoxy compounds - low dose exposures may result in vertigo, headache, malaise and paresthesias) and Lindane (organochlorines - nervous and immune system damage, hormone disruption, birth defects, breast cancer).