Excessive use of pesticides in developing countries has led to health and environmental problems

By D.K. Srivastava, Rita Pandey and C. Bhujanga Rao

DEEP concern is expressed about the excessive use of pesticides in developing countries, which is reported to have led to environmental degradation. Farah (1994) shows that some pesticides persist longer than others or break down to even more toxic components, extending the time span in which they could contaminate agricultural crops, underground water and surface water bodies. Pesticides affect not only the location of their application but also the ecosystems far removed due to their mobility in air and water. Further, pesticides usually kill pests and their natural enemies alike.

Pests are also very adept at developing resistance against the chemical pesticides intended to control them. Thus, pesticide use initiated to suppress pests may lead to greater pest outbreaks. The study notes that towards the late 1980s, with the growth of herbicide use, at least 48 weed species had gained resistance to chemicals. Another source estimates that from 1930 to 1960, the number of resistant anthropoid species (insects, mites, ticks) rose from just six to 137, an average increase of four resistant species per year. In the period of 1960-80, on an average 13 species per year are reported to have gained resistance to chemical pesticides. It was estimated that in 1990 approximately 504 insect and mite species had acquired resistance to pesticides in use.

The wiping out of essential predatory insects due to excessive and uncontrolled pesticide treatments has created new pests. For instance, in cotton production in the Canete Valley in Peru, spraying to control the tobacco budworm led to the rapid build-up of the cotton aphid. As chemical treatment intensified to counteract this resistance build-up, other pests developed because their natural predators were eliminated. In Mexico, the tobacco budworm developed resistance to all known pesticides and caused the cotton planted area to drop from more than 280,000 ha to a mere 400 ha in the 1960s. Similarly, in Nicaragua, 15 years of heavy insecticide use on cotton were followed by four years in which yields fell by 30 per cent.

Pesticide-related poisoning could occur in human beings as a result of excessive exposure to pesticides, through inhalation or on consuming heavily or untimely pesticide-treated crops. Karwasra et al. (1997) assess the impact of agricultural development on nature and extent of resource degradation in Haryana. They observe that in the central-southern districts, intensive canal irrigation has led to water logging and increase in salinity and this has encouraged profuse growth of weeds and insect pests.

To control such infestation and to propel any further harvest, intensive chemical control measures will have to be employed. The study notes that the direct ill-effects of farm chemicals have started showing its presence in the form of nitrate concentration in water and pesticides residue in different food items. Bhatnagar and Thakur (1998) observe that in Haryana from 1966 to 1993 both consumption and coverage of area by pesticides have shown accelerating growth rates. Consumption of pesticides has grown at a higher rate than the growth in areas covered by the use of pesticides.

Farah (1994) notes that the pesticide users are hardly aware of the negative externalities on the environment. In the absence of government intervention through regulations and taxation, they tend to overuse pesticides and this tendency is further exacerbated due to international and national institutional economic policies which directly or indirectly lead to farmers applying more pesticides than they would otherwise.

According to Joshi (1997), pesticide consumption in Indian agriculture has increased manifold during the last three decades. Five states, namely Andhra Pradesh, Gujarat, Maharashtra, Punjab and Tamil Nadu, accounted for more than 90 per cent of the pesticide use in the country, although the average consumption of pesticide in India is low, 33 grams/hectare. Indiscriminate use of pesticide in some pockets is causing several environmental and health problems. Farah reports that, during the 1989/90 season, $27 million worth of pesticides were used in the district of Guntur in the state of Andhra Pradesh. With an average overuse of 20 per cent, $5.4 million of pesticides were wasted, which could have been avoided through better pest management. The yield losses due to pest resistance were estimated at $39.7 million. In pesticide application, the red triangle label (extremely hazardous) chemicals have a share of 26 per cent in Andhra Pradesh, 39.7 per cent in Punjab and as high as 65 per cent in Gujarat of the reported use.

The yellow triangle label (highly hazardous) group constitutes 59 per cent each in Andhra Pradesh and Punjab and 34 per cent in Gujarat of the reported use. An analysis of the pesticide-use behaviour found that pesticide-use levels are determined significantly by the extent of irrigation. The intensity of use is higher on small farms. Joshi shows that with the increase in pesticide use in Punjab, 525 insects have already developed resistance to pesticides. Marothia (1997) reports that nearly 70 per cent of all pesticides consumed by Indian farmers belong to banned or severely restricted categories in the developed countries.

The Indian Council of Medical Research conducted an extensive study in 1993 covering all the states of India. Results of this study indicate that the samples far exceeded the tolerance limits of pesticide residuals in the case of milk, canned fruit products, poultry feeds and vegetables. The report emphasises that the private benefits of pesticides use should be evaluated against their social costs. It has been estimated that only 10 per cent of the total food grains production can be saved from increased pesticide use. Once the health hazards and other costs are imputed, these benefits appear too meagre.

Pesticides also find their way into the river through agricultural runoffs because the upstream catchment areas are intensely cultivated. Around 150 tons of pesticides and herbicides are used in the agricultural and plantation areas. The deadly impact of these chemicals has caused destruction of several types of fish and aquatic organisms in recent years.

The above excerpt is taken from the chapter, ‘Role of Environmental Subsidies in India’ by D.K. Srivastava, Rita Pandey and C. Bhujanga Rao.

Excerpted with permission from Environment and Fiscal Reforms in India Edited by D.K. Srivastava, Chief Policy Advisor, EY India and Honorary Professor, Madras School of Economics, and K.S. Kavi Kumar, Madras School of Economics, Chennai, India

Hardback

SAGE India, 2015

ISBN 9789351500414

364pp.