ABSTRACT
Airborne residues can undergo local downwind and long-range transport. They can also decompose by oxidations and photochemical reactions. Detailed examples are given for pesticide drift and airborne residues in and around California’s Central Valley and Sierra Nevada Mountains. The pesticides that enter the air are carried downwind from agricultural sources where they contact wildlife, and nontarget vegetation and water bodies. Examples cited focus on organophosphates and their exposure to red tail hawks, and their further intrusion into the Sierra Nevada foothills and higher mountains. The finding of PCB in the Lake Tahoe Basin is another example of unanticipated long-range transport and unanticipated deposition. Deposited PCBs are bioaccumulated in trout in the Lake Tahoe Basin. Dicamba herbicide is another example of drift under current study by the registrant and other research groups.
