The toxic trail: Pesticide pollution and its impact on India

India's agricultural sector has significantly contributed to food security and economic development. However, the indiscriminate use of pesticides has led to severe environmental and health consequences. Pesticide pollution affects soil, water, and biodiversity, leading to long-term damage to ecosystems and human well-being. This paper ‘Pesticide pollution in India: Environmental and health risks, and policy challenges’ from ‘Toxicology Reports’ by Kashyap et al., explores the extent of pesticide pollution in India, its impact on the environment and health, and the necessary policy interventions to mitigate its effects.

The rise of pesticide use in India

India ranks among the top pesticide-producing countries globally, but its per-hectare pesticide consumption remains lower than that of developed nations. Despite this, intensive farming practices have led to widespread pesticide application, particularly in states like Punjab, Uttar Pradesh, and Maharashtra. Commonly used pesticides include organochlorines, organophosphates, and synthetic pyrethroids, many of which persist in the environment and bioaccumulate in the food chain.

Environmental consequences of pesticide pollution

Pesticide residues have been detected in surface water, groundwater, and soil across various Indian states, often exceeding permissible limits set by the World Health Organization (WHO) and the Bureau of Indian Standards (BIS). Key environmental impacts include:

• Soil contamination: Pesticides alter soil microbial communities, reducing fertility and affecting crop yields. The chemical composition of the soil changes, leading to the depletion of essential nutrients. The presence of persistent pesticides can also hinder the growth of beneficial microorganisms, disrupting the natural nutrient cycle.

• Water pollution: Runoff and leaching lead to pesticide contamination of rivers, lakes, and groundwater, posing risks to aquatic life and drinking water sources. Many pesticides have high water solubility, allowing them to infiltrate deep into underground water reserves, leading to long-term contamination that is difficult to remediate. This contamination not only affects aquatic ecosystems but also enters the food chain through fish and other marine organisms.

• Biodiversity loss: Non-target species, including beneficial insects, birds, and fish, suffer from pesticide exposure, leading to ecosystem imbalances. Pollinators such as bees and butterflies are particularly vulnerable, resulting in reduced crop pollination and decreased agricultural productivity. Additionally, pesticides disrupt predator-prey relationships, leading to increased populations of certain pest species, which further damages crops.

Health implications of pesticide exposure

Human exposure to pesticides occurs through contaminated food, water, air, and occupational contact. Health risks include:

• Acute poisoning: Symptoms such as nausea, dizziness, respiratory distress, and neurological damage. Farmers and agricultural workers who handle pesticides without proper protective measures are at a higher risk of experiencing immediate poisoning effects.

• Chronic diseases: Long-term exposure has been linked to cancer, endocrine disruption, reproductive issues, and developmental disorders. Studies have shown a correlation between pesticide exposure and neurodegenerative diseases such as Parkinson’s and Alzheimer’s. Children and pregnant women are particularly vulnerable, as exposure during developmental stages can lead to birth defects and cognitive impairments.

• Bioaccumulation: Persistent organic pollutants (POPs) like DDT and HCH accumulate in human tissues, affecting immune and hormonal systems. These chemicals, once ingested, can persist in the body for years, leading to long-term health effects that may not be immediately evident.

State-wise analysis of pesticide contamination

Studies have reported varying levels of pesticide residues across India:

• Punjab and Haryana: High levels of organophosphate residues in groundwater, leading to increased cases of cancer and neurological disorders in affected regions. The overuse of pesticides in wheat and rice farming has resulted in contamination of drinking water sources, posing long-term health risks.

• Kerala and Tamil Nadu: Endosulfan contamination linked to severe health crises, including congenital disabilities and infertility among the local population. The Kasaragod district of Kerala witnessed one of the worst pesticide-related tragedies, where long-term exposure to endosulfan led to developmental disorders, reproductive health issues, and neurological impairments.

• Maharashtra and Uttar Pradesh: Chlorpyrifos and malathion detected in drinking water sources, increasing the risk of acute and chronic health issues among residents. In Vidarbha, Maharashtra, excessive pesticide usage in cotton farming has led to an increase in farmer suicides due to pesticide poisoning.

• West Bengal and Assam: Presence of DDT, HCH, and organophosphates in soil and water bodies due to intensive pesticide application in tea plantations. Many tea estates have reported pesticide residues in exported tea products, leading to international trade concerns.

• Rajasthan and Madhya Pradesh: High levels of pesticide residues found in groundwater, affecting livestock health and agricultural productivity. Desert ecosystems in Rajasthan are particularly vulnerable, as pesticide runoff from irrigated farmlands accumulates in scarce water sources.

• Gujarat and Karnataka: Increased pesticide residues in vegetable and fruit crops, leading to food safety concerns. Market surveys have shown that residues in commonly consumed vegetables such as tomatoes, brinjals, and cucumbers frequently exceed permissible limits.

• Bihar and Odisha: Pesticide contamination in surface water bodies impacting fisheries and aquatic ecosystems. Local communities dependent on river-based fishing have reported reduced fish populations and declining incomes due to pesticide-induced ecological imbalances.

Policy and regulatory challenges

India's regulatory framework for pesticide use is governed by the Insecticides Act of 1968, but enforcement remains weak. Challenges include:

• Lack of monitoring: Inadequate infrastructure for testing and monitoring pesticide residues. Many testing facilities are concentrated in urban centers, making it difficult for rural farmers to access reliable monitoring services. Strengthening laboratory networks and ensuring regular surveillance at multiple points in the supply chain is necessary.

• Regulatory loopholes: Continued use of banned or restricted pesticides due to weak enforcement. Many hazardous pesticides are still available in local markets due to insufficient oversight and corruption. The government needs to establish a robust digital tracking system to prevent unauthorized sales and develop stricter penalties for illegal trade.

• Farmer awareness: Limited knowledge about safe pesticide use and alternatives like Integrated Pest Management (IPM). Many small-scale farmers rely on traditional pesticide application methods without understanding their long-term environmental and health consequences. More targeted extension services, mobile advisory units, and demonstration programs should be implemented to promote sustainable practices.

• Subsidies and incentives: Current subsidy structures often favour chemical pesticides over eco-friendly alternatives. Restructuring financial incentives to promote biopesticides, organic farming, and non-chemical pest control methods is critical to reducing pesticide dependency. Government schemes should include direct financial support for farmers transitioning to sustainable farming practices.

Pesticide pollution in India poses a significant threat to environmental sustainability and public health. Addressing this issue requires stringent policy measures, scientific advancements, and community engagement. By adopting sustainable agricultural practices, strengthening regulations, and fostering research in eco-friendly alternatives, India can mitigate the adverse effects of pesticide pollution and ensure a healthier future for both its people and ecosystems.

The full paper can be accessed here