Which method is the most reliable for assessing the risk of inhaling hazardous pesticides during agricultural application?
Different methods are reported in the literature to evaluate the risk.
a. Exposure Assessment by quantifying the amount of pesticide released into the air during application and estimating the concentration of airborne pesticides in the application area.
a. Exposure Assessment by quantifying the amount of pesticide released into the air during application and estimating the concentration of airborne pesticides in the application area.
b. Toxicological Assessment by determining the toxicity of the pesticides being used, including their potential to cause adverse health effects through inhalation exposure.
c. Personal Monitoring by using personal air sampling devices to measure the actual exposure levels experienced by workers during pesticide application.
d. Risk Characterization by Integrating dose-response relationships, exposure duration, and individual susceptibility.
d. Risk Characterization by Integrating dose-response relationships, exposure duration, and individual susceptibility.
Analytical toxicology
Environmental fate and transport
Exposure assessment
Forensic toxicology
Risk assessment
afelsot
The EPA maintains a database of occupational pesticide exposure scenarios that is populated with empirical studies collected over many years that forms the basis for modeling inhalational and dermal exposure from different activities. The database is named PHED, Pesticide Handler's Exposure Database. A combination of personal air monitoring near the breathing zone and urinary analysis provides the best evidence of exposure. However, inhalational exposures are disproportionately low compared to dermal exposures with the hands arguably being the biggest source of exposure. Based on the modeling using PHED for new compounds and knowing their rates of application and other use scenarios, exposure via inhalation is incorporated into FIFRA risk assessments. See URL https://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/occupational-pesticide-handler-exposure-data for access to the model and policies regarding worker exposure data reporting for registration purposes. The academic literature supports the conclusion that ag worker exposure via inhalation is quite low compared to dermal exposure. I'm in agreement that the modeling studies using PHED for any pesticide use scenario defines EPA decisions as to what type of PPE should appear on product labels, which is located in the box referring to the Worker Protection Standard.
Mark Gebert
If personal monitoring is not practical or possible, then exposure assessment by quantifying the amount and concentration of airborne pesticide is a possible alternative. However, if the pesticide has a high toxicity, it is likely that personal monitoring will be required as a follow up to ensure the safety of the workers.
Toxicological assessment and risk characterization are both necessary but separate analysis and have no way of predicting the amount of pesticide actually inhaled during application.
If the pesticide is particularly toxic and inhalation exposure above acceptable limits is predicted or confirmed, then this can be mitigated with personal protective devices or engineering controls.