Assessing the environmental impact of changes in pesticide use on transgenic crops

Two main traits that have been introduced into genetically modified crops that are currently on the market, viz., herbicide and insect resistance, likely affect pesticide use on these crops. Various surveys have been carried out, such as those of the USDAERS and NCFAP, comparing the pesticide use on genetically modified versus conventional crops. Environmental indicators for pesticides may aid in comparing the outcomes of such assays in terms of environmental impact. Previously we applied one indicator, the Environmental Impact Quotient, to pesticide-use data for commercial biotech crops from a recent survey by NCFAP and found that, by this method, the impact paralleled the decreased use of pesticides. The output of many environmental indicators, while lending themselves to comparison of pesticides, is abstract and there may be a need for specific indicators that lend themselves for comparison with other agricultural factors or that are expressed in more tangible terms, e.g., monetary indicators. IUPAC recently initiated a project on the assessment of the environmental impact of altered pesticide use on transgenic crops, with the aim of providing input for risk-benefit analysis of the adoption of genetically modified crops. In conclusion, the use of appropriate environmental indicators enables the assessment of the economic and environmental effects of agricultural biotechnology, including that of altered pesticide use