Bt Cotton

Farmer exposure to insecticide and health implications

Chemical insecticides used in cotton have high toxicity to humans (USEPA 2001). Conversely, the insecticidal protein produced in Bt cotton has been deemed to pose “no foreseeable human health hazards” (USEPA 1998). The replacement of the chemical insecticides with Bt cotton has clearly reduced the risks to farm workers and to others in the farm community who may be exposed (Betz et al 2000). These effects are particularly important in regions of the world where modern application techniques are not always adopted or are even available for use. The World Health Organization (WHO) reported an estimated 500,000 insecticide poisonings per year resulting in 5,000 deaths (Farah 1994). Whereas caution is advised in interpreting these statistics (Yudelman et al 1998), the practice of insecticide application can be hazardous if precautions are not taken. Even in industrial countries, where farmers normally take the necessary precautions, non-adherence to recommended practices for the safe and effective use of insecticides leads to insecticide poisonings amongst farmers. The Environmental Protection Agency (EPA) in the US estimates that US agricultural workers suffered between 10,000 and 20,000 insecticide poisonings a year (Phipps and Park 2002).

Surveys in South Africa (Rother 1998) confirm that due to lack of awareness, inadequate protective clothing and the necessary training, women farmers in the Makhathini Flats in South Africa often mixed insecticides with their hands, discarding surplus insecticide carelessly so that it contaminated domestic water supplies. The women also collected spray-contaminated edible weeds from cotton fields sprayed with insecticides. The health benefits of Bt cotton are especially beneficial for women and children as it precludes direct exposure (women and children actively participate in the spray program), but also reduces contamination of water utensils, as discarded insecticide containers are often reused for carrying water (Ismael et al 2002a,b). These reports and others (Repetto and Baliga 1996, Rola and Pingali 1993) confirm the widespread risk that farmers are exposed to, particularly in developing countries, where insecticides are applied under difficult and hazardous conditions.

Surveys of Bt cotton in China from 1999 to 2001 have consistently shown that on average the incidence of insecticide poisonings for farmers using Bt cotton is up to four times less than farmers using conventional cotton, which requires up to 28 insecticide sprays per season (Pray et al 2002). There is also circumstantial evidence from South Africa that the use of Bt cotton results in a decrease in insecticide poisonings (Ismael et al 2002a).

The Plant Industry has long recognized the need to mount educational/training programs to promote the safe and efficient use of crop protection products. Crop Life International has expanded these activities and currently, training in safe use of insecticides is being conducted in more than 70 countries (Crop Life International 2002).

Summary topics:

• Agronomic Benefits
• Environmental Benefits
  • Reduction in use of cotton insecticides
  • Less insecticides in aquifers and the environment
  • Reduced production risks and enhanced opportunities to grow Bt cotton
  • Increased populations of beneficial insects
  • Reduced risk for wildlife
  • Reduced fuel and raw material consumption, and pollution
• Social benefits
  • Social implications of saving water by reducing number of insecticide sprays
• Economic benefits
  • China
  • USA
  • India
  • Others
  • Distribution of economic surplus to Bt cotton stakeholders

Related topics:

• The cotton crop
• Global distribution of cotton in developing and industrial countries, by area, production, consumption, imports, and exports
• Number of cotton farmers worldwide and size of farms
• Insect pests of cotton
• Crop losses due to insect pests of cotton and the cost of control
• Global insecticide usage on cotton
• The use of Bt genes in cotton
• Assessment of environmental risk and Insect Resistance Management (IRM) strategies
• Global adoption of Bt cotton
• Bt cotton experience to date
• Summary: Agronomic, Environmental, Social and Economic Benefits
• Future global potential for Bt cotton: opportunities and challenges
• Highlights

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