Related Experiment Videos
Reentry field data and conclusions
1University of Iowa, Institute of Agricultural Medicine and Occupational Health, Iowa City 52242.
Reviews of Environmental Contamination and Toxicology
|January 1, 1992
Summary
Current reentry intervals for pesticides, particularly those regulated by the EPA, are often inadequate, necessitating longer intervals to protect agricultural workers from acute and chronic exposure risks.
Area of Science:
- Agricultural Science
- Environmental Toxicology
- Pesticide Regulation
Background:
- Existing reentry intervals for pesticides face scrutiny due to deficiencies in regulatory data.
- Lack of information on harvester exposure frequency hinders realistic chronic exposure limits.
Purpose of the Study:
- To evaluate the adequacy of current reentry intervals for pesticides based on foliar residue data.
- To identify deficiencies in data required for establishing improved reentry intervals.
- To propose criteria for acceptable cholinesterase inhibition (4% daily, 50% acute).
Main Methods:
- Review of reported foliar residue data.
- Comparison of existing reentry intervals with a unified field model assessment.
- Analysis based on established criteria for acute and chronic cholinesterase inhibition.
Main Results:
- EPA reentry intervals for nine insecticides were found to be inadequate based on the model.
- California's reentry intervals were generally found to be adequate, with a few exceptions.
- The unified field model, developed under realistic conditions, largely supports California's regulations but suggests improvements are needed elsewhere.
Conclusions:
- Current reentry intervals, especially EPA's, may not sufficiently protect harvesters from pesticide exposure.
- More comprehensive residue data, metabolite toxicity, and harvester exposure pattern surveys are needed for future interval setting.
- There is sufficient evidence to justify longer reentry intervals nationally to enhance harvester protection.