Evaluating risk predictions at population and community levels in pesticide registration-hypotheses to be tested
✍ Scribed by Lawrence A. Kapustka; Bill A. Williams; Anne Fairbrother
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 87 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0730-7268
No coin nor oath required. For personal study only.
✦ Synopsis
Chemical registrations under FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act) and TSCA (Toxic Substance Control Act) in the United States, and equivalent regulations in Canada and Europe, are driven extensively by risk assessments. Chemicals intended for use as pesticides are evaluated by considering fate and transport, toxicity, and assumed exposure scenarios. For nonpesticide chemicals, very limited testing information is generated to support the risk management decisions. Despite the restricted quantity of information, risk-based predictions are intended to provide analyses that are adequate to evaluate ecological safety margins. Persistent questions regarding adequacy of protection have dogged risk assessors, regulators, and registrants. From a scientific perspective, risk assessments are essentially complex hypotheses, not conclusive or factual statements. Given the great reliance on extrapolations from individual-based toxicity (and generally poor exposure characterizations) to statements of community, ecosystem, landscape, regional, and even global levels of organization, it is perhaps remarkable that the system has worked at all. But do we really know if the system works? If we wish to retain a scientific basis in registration, follow-up work that tests the risk-prediction hypotheses needs to be done. Properly structured around testable parameters, focused monitoring programs could reduce much of the mystery embodied in current practice. Greater reliance on monitoring data to test risk predictions could reduce the tendency to concatenate uncertainty factors that unnecessarily expand Type II errors. We propose changes in the registration process to address these concerns.