Summertime transport of current-use pesticides from California's central valley to the Sierra Nevada Mountain Range, USA
LeNoir JS, McConnell LL, Fellers GM, Cahill TM, Seiber JN. 1999. Summertime transport of current-use pesticides from California's central valley to the Sierra Nevada Mountain Range, USA. Environmental Toxicology and Chemistry. 18(12):2715–2722
Agricultural activity in California's Central Valley may be an important source of pesticides that are transported in the air to the Sierra Nevada mountain range, USA. Pesticides applied to this intensive crop production area may volatilize under warm temperatures typical of the valley and be transported through the atmosphere to be deposited in the cooler, higher elevation regions of the Sierra Nevada mountains. To determine the extent of summertime atmospheric transport of pesticides to this region, high volume air, dry depositing, and surface water samples were collected in the Central Valley and at different elevations in California's Sequoia National Park. Results revealed that the highest residue concentrations were those of compounds with heavy summertime agricultural use. A significant drop in pesticide concentrations in both air and water samples was observed within a few 100 m elevation from the valley; however, levels remained relatively consistent between ~500 and 2000 m. Water concentrations from two areas above 3000 m contained levels less than a tenth as high as those at lower elevations. Possible effects of the pesticides were estimated using measured water concentrations to calculate total exposure of three aquatic species to organophosphate insecticides. Aggregate exposure calculations showed concentrations were well below 96 h LC50 values for rainbow trout and stonefly but concentrations may be harmful to amphipods.
- Type
- Journal Article
- Authors
- LeNoir, James; McConnell, Laura; Fellers, Gary; Cahill, Thomas; Seiber, James
- Units
- ARD , SEKI , YOSE
- Keywords
- Air Pollution Effects, AIRBIB, ARD_Park-Air-Info_Collection, Atmospheric transport, chlorpyrifos, Deposition, Endosulfan, Nitrogen, Sierra Nevada Mountains, Sulfur