The World Bank has noted overuse of chemical pesticides in developing countries leading to high health costs, which outweighed the benefits. It has identified that excessive use of nitrogenous fertilizers was one of the major cause of the farm sector's contribution to non-carbon dioxide emission to global warming process.
In its recent World Development Report-2008, it said, "many farmers in developing countries overuse pesticides and do not take proper safety precautions because they do not understand the risks and fear smaller harvests. Making matters worse, developing countries seldom have strong regulatory systems for dangerous chemicals. Pesticides banned or restricted in industrial countries are used widely in developing countries.
It further said that farmer perceptions of appropriate pesticide use varied with the setting and culture. It was common in Latin America for farmers to believe that exposure to pesticides increases their tolerance and makes them stronger and more able to work and this often led to very high exposure, it said.
In a potato-farming community in Carchi, Ecuador, researchers documented 171 pesticides poisoning per 100,000 people per year in the late 1990s – among the highest in the world. Pesticide poisoning there was the second largest cause of death for men (19%) and fourth for women (13%), the report noted and urged the national governments "to reduce accessibility to more dangerous agrochemicals through banning or taxing their use."
In the Philippines in 1989-91 farmers commonly applied two insecticide doses per growing season, elevating their health costs by an average of 70% above those who did not use pesticides. The yield benefits from pesticide use were more than offset by the cost of illness.
The report said that natural control and integrated pest management showed promise. Farmers who focused on naturally preventing or suppressing pests and used pesticides only when necessary substantially reduced exposure while maintaining yields and increasing profitability. In Nicaragua farmers trained in appropriate pesticide use suffered lower exposure after two years and had higher net returns than did those not trained.
"Likewise, Indian farmers growing Bt cotton used less insecticide and gained significant yield increases, with the additional advantage of more stable yields. While Bt cotton has been rapidly and successfully adopted in Gujarat, Maharashtra, Karnataka and Tamil Nadu, farmers in Andhra Pradesh initially experienced a loss, largely because of the use of poorly adapted varieties (hybrids?)," it said.
The report also noted that nitrous oxide emissions from soils due the use of chemical fertilizers and... methane from enteric fermentation in livestock production each accounted for about one-third of agriculture's total non-carbon dioxide emissions and were projected to rise and further contribute to global warming....
