Understanding the Impact of Pesticides on Environment in a New Light

Posted on
27 January 2014

Although it is well known and acknowledged that pesticides are harmful for the environment and human health, we often do not know how to evaluate and control the extent of the damage.

As the world population is rising, it is causing a steep increase in the demand for food and fibre production. In order to meet this requirement, greater usage of pesticides is observed all over the world, which is a major hurdle in the path towards sustainable agriculture production.

In order to ensure sustainability in agriculture, WWF-India is working on the Better Cotton Initiative (BCI) with cotton growers in Aurangabad and Jalna districts of Maharashtra, India. The main objective of the WWF project is to produce better cotton by complying with environmentally benign practices and socially stable processes. It is known that cotton as a crop is one of the heaviest users of chemical pesticides and consumes 44.5 per cent of the total pesticides used in India. These pesticides add persistent chemicals to ecosystems which can have adverse impacts on humans and wildlife by permeating through the food chain. They tend to accumulate in the soil and in biota, and their residue reaches the surface and groundwater through leaching. Different groups of pesticides have different types of effects on the environment. It is therefore important to understand the risks associated with a wide range of pesticide application.

Better Cotton Initiative is a global initiative aiming at: i) Reducing the environmental impact of cotton production, ii) Improving livelihoods and economic development in cotton producing areas, iii) Improving commitment to and flow of better cotton throughout the supply chain, and iv) Ensuring the credibility and sustainability of the Better Cotton Initiative. BCI exists to make global cotton production better for the people who produce it, better for the environment it grows in, and better for the sector’s future.

The Integrated Pest Management (IPM) programme, a component of the Better Management Practices proposed by WWF-India, focuses on reducing use of pesticides and in turn, reducing the burden on the environment. IPM uses a combination of methods including spraying of pesticide in recommended doses. Pesticides in the IPM programme are generally chosen based on their efficacy, cost and availability rather than their potential impact on the environment. These are various methods used to quantify pesticide use, such as the number of sprays, amount of active ingredients, and so on. However, none of these methods assess the environmental impact of a specific scale.

A better and more accurate representation of pesticide application and its reaction to the environment is by estimating the amount of active ingredients in different pesticides applied per hectare. But again, this indicator only provides an aggregation, and tends to ignore toxicity, mobility, level of persistence, spatial and application variances, and the environmental impact of chemicals.

In order to simplify and organize the data, a mathematical model called the Environment Impact Quotient (EIQ) was developed by Cornell University, which would help ascertain the effects of pesticides on different aspects of the environment. It addresses a majority of environmental concerns that are encountered in agricultural systems, including farm worker, consumer, wildlife, health, and safety. Dr OP Sharma, Principal Scientist at the National Centre for Integrated Pest Management, Indian Council for Agricultural Research says, “The efforts which WWF project is putting in are surely helpful in conserving the biodiversity at present and for the future. Although there are a number of predators and parasitoids which are known, many others which are very small in size are being allowed to play their role, so by reducing the load of pesticide in the environment, we are definitely conserving them.”

Environment Impact Quotient (EIQ) – EIQ represents a method to calculate the environmental impact of pesticides, and the values obtained from these calculations can be used to compare different pesticides and pest management programmes to ultimately determine which programme or pesticide is likely to have the lower environmental impact.

The results of EIQ are helping the project in identifying restrictions in the use of certain pesticides, such as acephate, so as to avoid water contamination as the chemical persists both in water as well as in sediments. Similarly, some of the groups of pesticides identified – the Neonicotinoids group along with Monocrotophos – need to be completely replaced with alternative pesticides as they are highly toxic to honeybees, leading to a reduction in pollination by 14 per cent.

EIQ therefore is a useful measure for gauging the effects of pesticides on the environment and is helping to improve the application of the IPM programme in India.


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