Protocol, field applicator exposure

The following describes important considerations that we have found to be essential to a well-designed field applicator exposure to pesticide study. First, a detailed protocol critiqued by several knowledgeable researchers is essential. It is nearly impossible to devise a protocol which has too much detail. One must attempt to plan for all of the possible pitfalls which may occur. 

Dermal Exposure Levels. Setting acceptable maximum dermal exposure levels to specific pesticides has been difficult. This is primarily due to a lack of specific data on dermal transport rates for specific pesticides as related to adverse effect levels and presumed no-effect levels. We are now requiring such data from the registrants, and our Department has a suggested protocol (1) that is offered to registrants that will provide such information from animal exposure studies. This dermal transport rate information is important in setting minimum field reentry intervals for field workers as well as in evaluating exposure levels of mixers, loaders, and applicators. 

The exposure periods required to obtain sufficient sensitivity to measure VOCs in low pg/m concentrations using diffusive samplers are typically several days or weeks. It would be a major task to apply the laboratory and field tests required by protocols to evaluate diffusive monitors used in the workplace for these long exposure periods. At present the uncertainty associated with measurement by diffusive samplers requires further investigation, but a number of studies have shown them to be applicable to the measurement of VOCs in indoor air. 

---