Over the past ten years that farmers in India have been planting Bt cotton – a transgenic variety containing genes from the soil bacterium Bacillus thuringiensis making it pest resistant – pesticide use has been cut by at least half, a new study shows.
The research also found that the use of Bt cotton helps to avoid at least 2.4 million cases of pesticide poisoning in Indian farmers each year, saving US$14 million in annual health costs. (See Nature’s previous coverage of Bt cotton uptake in India here.)
The study on the economic and environmental of Bt cotton is the most accurate to date and the only long term survey of Bt cotton farmers in a developing country.
Previous studies have suggested that farmers planting Bt cotton use less pesticides. But these older studies did not establish a causal link and few quantified the environmental, economic and health costs and benefits.
The current study, published online in the journal Ecological Economics, surveyed Indian cotton farmers between 2002 and 2008. India is now the world’s biggest producer of Bt cotton with an estimated 23.2 million acres planting in 2010. Farmers were asked to provide agronomic, socio-economic and health data, including details of pesticide use and frequency and type of pesticide poisonings such as eye and skin irritations. Farmers who suffered pesticide poisoning provided details about heath treatment costs and costs associated with lost labour days. The survey was repeated every two years.
“The results demonstrate that Bt cotton has notably reduced the incidence of pesticide poisoning among small holder farmers in India,” the study says.
Public debates about transgenic crops should focus more on the health and environmental benefits which can be “substantial” and not just the risks, the study adds.
Kouser, S. & Qaim, M. Ecol. Econ. http://dx.doi.org/10.1016/j.ecolecon.2011.06.008 (2011)
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