By- Dr.KrutikaPramodKhiratkar, Dr. Kevin James
andDr. Swati Umap
Introduction:
Pesticides are the chemical (carbamate) or biological agent (virus, bacteria, or fungi) which kill or incapacitates the pest. Pests can be of many types such as insects, weeds, fishes, plant pathogens, molluscs, mammals, nematodes, and microbes that destroy the property and spread diseases. Pesticides term includes herbicide (for plants),molluscicides (for snails), insect repellent (for insects), bactericide( for bacteria),antimicrobials, miticides(for mites),rodenticide (for rodents), avicides (for birds),algaecides (for algae),nematocides (for nematodes) ,fungicide(for fungi and oomycetes) and animal repellent. Pesticides importantly used in agriculture for plant protection.
India’s status:
India is the second-largest manufacturer of pesticides in Asia after China while holds the twelfth position for its consumption. Production of pesticides in India started in the year 1952 near Calcutta manufacturing DDT (dichloro diphenyl trichloroethane), HCH (hexachlorocyclohexane) and BHC (benzene hexachloride). In the Indian scenario, pesticide consumption is highest in Maharashtra, followed by Uttar Pradesh, Punjab, and Haryana. These pesticides are not easily degradable thus residing in the soil, groundwater, and surface water and contaminates the environment widely.
Residues and their effects:
Due to its vast use, pesticides have been a threat to humans as well as for livestock due to their accumulating behaviour. Residues accumulate in the animal tissues by its direct use on the animal body as an external ectoparasitic agent or indirectly by rearing or feeding the livestock on pesticide-treated fodder, crops. Pesticides used for plant and soil and also contaminates the surface water which acts as a source of spread for animals. Due to the lipophilic nature of the pesticides, they accumulate in milk and other fat-rich substances in animals. The greatest accumulation has been observed in chicken muscle followed by goat and beef.
The first human pesticide poisoning was reported in Kerala in 1958 by the consumption of wheat flour contaminated with parathion. Also, the Bhopal gas tragedy which occurred in Bhopal, Madhya Pradesh was the worst industrial disaster that occurred due to the accidental leak of methyl isocyanate from the pesticide factory. Humans get exposed to pesticides by different means such as ingestion, inhalation, and dermal contact which leads to the development of acute and chronic health issues. The acute form is mostly misdiagnosed and can cause blurred vision, headache, salivation, diarrhoea, vomiting, eye and skin conditions, seizure, and even coma. Chronic form leads to more severe problems causing neurological damage increasing the risk of Parkinson’s disease, also leads to memory disorders, reproductive disordersand miscarriages, reduced co-ordination, and also can cause cancer.
Managemental practices:
For the control of pesticide residues, maximum residue levels i.e. the highest amount of pesticide residue that is tolerated in food or feed is set up by food safety and standard authority of India (FSSAI). Many pesticides have been banned due to their ill effects including Aldrin, Calcium cyanide, Dieldrin, Nicotine sulphate, etc. Certain measures should be followed to minimize the pesticide residues such as educating the farmers and animal owners about the residue ill effects on humans and animals, by switching to organic farming, integrated pest management (IPM) in which the control of pest is done by crop rotation method is also an effective way.
