Regulate The Use Of Pesticides

The World Health Organisation (WHO) broadly defines a pesticide as any substance or mixture of substances intended for preventing, destroying, or controlling any pest, including vectors of human or animal disease, and unwanted species of plants or animals causing harm during or otherwise interfering with the production, processing, storage, transport, or marketing of food, agricultural commodities, wood, and wood products, or animal feedstuffs. This write-up will focus on the use of pesticides in vegetables that we consume daily. It's used as defoliant, desiccant or agent for thinning fruit or preventing the premature fall of fruit. The WHO divides pesticides in four categories - green, blue, yellow and red. Green pesticides are safer to use as they are made up of natural products but the red ones are detrimental to health.

Accountability

Counting of generation of pesticides started from 1940, which primarily consisted of natural substances and minerals. At that time, extracts from plants like nicotine (from tobacco), pyrethrum (from chrysanthemum flowers), and rotenone (from tropical plants) were used as early insecticides. There was no concept of accurate accountability about serious health issues and environmental damage. So, some of pesticides like mercy based compounds were highly toxic to humans and animals. Currently we are in the 4th generation, also known as age of harmon based pesticides which started from 2000 and continues to this date. They include biopesticides and genetically engineered (GE) crops that produce their own pest resistance. 

Fourth-generation pesticides are designed to target specific pests with minimal impact on non-target species, including beneficial insects and pollinators.  They are more environmental friendly, and less toxic compared to those used in the past. Regulation of bio-pesticides with the introduction of genetically modified organism is the biggest challenge and also the matter of debate regarding its safety and environmental impact on the planet. 

In 1962, Rachel Carson published a book about environmental science - 'Silent Spring'. It highlighted the harmful impact of pesticide on wildlife, especially birds, and its potential risks to human health. After 10 years of publication of the book, the U.S Environmental Protection Agency (EPA) banned DDT (dichlorodiphenyltrichloroethane) citing its negative effects on environment and human health. It was banned in Nepal in 2001. To date, 24 types of pesticides such as DDT, BHC, Chlorodane, Dialdrain, Ammonium Phosphide etc. have been banned.

A few days ago, a news report spread like a wild fire: Cancer was diagnosed in 61 people in Gandaki Rural Municipality, Gorkha, 15 of them had kidney failure and all were involved in commercial agriculture as a farmer. This is an eye lens of microscope to see the whole scenario of agriculture in Nepal. There is a misconception in farmers that pesticides are medicine not a poison, so they are not much conscious during spraying and applying pesticides in crops. Most of farmers are not well educated about the consequences of pesticides.

Exposure to pesticides acts as a stimulant to cancer, and chronic low-dose is considered one of the important risk factors for the increasing cancer incidence.  Breast cancer is the leading cause of cancer-related deaths among women. About 650 pesticides out of the 800 used worldwide can affect the functioning of the endocrine system and are called endocrine disrupting pesticides (EDPs). All women diagnosed with breast cancer between 1995 and 2005 in the city of Arica that received massive aerial applications of malathion in 1980 were 5.7 times more likely to suffer from breast cancer compared to women diagnosed during the same period in the city of Iquique, Chile. 

A research done in Nepal in 2019 in Rupandehi district and published in Science Direct Journal concluded that 93 per cent of eggplant and 100 per cent of tomato and chilli samples contained pesticide residues, with Omethoate, chloropyrifos, triazophos and carbendazim posing the biggest hazard.

Inspection and testing

Nepal is dependent on India for agricultural products. In 2023, according to the report of Division of Customs office, Nepal imported over 263 million kg of vegetables during 2023. Out of this, more than 101 million kg were sourced directly from India, which represents almost 38.68 per cent of the total imports. Approximately 94.11 per cent of tomatoes, 60 per cent of potatoes, 45 per cent of green peas, 66 per cent of pumpkins in the Nepali market came from across the border. The total cost of vegetable imports in that year amounted to around Rs 34 billion.   

There has been no proper inspection and testing for pesticide residues in imported vegetables and fruits by Nepal Government, making them risky to consume.  Stakeholders have called for the setting up of well-equipped lab to identify such residues in all 77 districts. Consumer, for their part, have to be conscious about the health risk and take measures to make fruits and vegetables safe to eat. 

They include, among others, dipping them in pure water for around 30 minutes before cooking, educating farmers about the workplace safety standards and proper pesticide management and storage – which lowers the risks of cancer and kidney failure – and developing proper ecosystem between agriculture expert and farmers through local government. 

(The author is a chemist and cancer researcher)