I read with interest your article on the pesticide drift study in Sisquoc (“A better alternative?” June 24)—in particular, the quote from Lea Brooks at the Department of Pesticide Regulation (DPR) calling into question the validity of the sampling methods used: “When [DPR] and Air Resources Board conduct monitoring, we follow U.S. EPA protocols,” she said. “Although we’re not familiar with this particular study, previous Drift Catcher studies have not used those protocols.”
As a PhD chemist with years of field experience with air monitoring and designer of the Drift Catcher (for which Pesticide Action Network received a 2008 Tech Museum Laureate award), I’d like to note a few points:
1) The Drift Catcher sampling methodology is identical to the methods that the Air Resources Board and DPR itself uses in their pesticide air monitoring for the Toxic Air Contaminant program and is based on NIOSH standard methods.
2) The Drift Catcher was reviewed by a Scientific Advisory Committee consisting of representatives from DPR, EPA Region 9, the U.S. Geological Survey, and the California Department of Public Health. They were satisfied that the methodology was sound.
3) The one place where PAN and DPR occasionally do things differently is in the calculation of the “acceptable” level of exposure. We include U.S. EPA’s child protection factors (when they are used by U.S. EPA) and DPR does not. Our goal is to protect children, and it thus seems prudent to include all protections for children. For the pesticide chloropicrin found in Sisquoc, there were no additional child protection factors.
We compared our data directly to DPR’s and EPA’s published levels of concern. The results show unequivocally that even when no errors are made during a fumigant application or no accidents happen, people living near fumigated fields are exposed to levels of chloropicrin that exceed acceptable cancer risks and acute toxicity risks.
This article appears in Jul 15-22, 2010.