Pesticide concentrations at a Shafter air monitoring station were found to be well below harmful levels in the nation's first long-term testing for such chemicals.
A report released Friday by the state Department of Pesticide Regulation said that in three agricultural areas including Shafter, only one of 34 chemicals and five associated breakdown products exceeded levels considered safe. The exception -- acrolein -- is believed to result from automobile or industrial emissions.
Kern County Farm Bureau President Steve Maniaci hailed the results as proof that the local agricultural community puts the community's health and safety first when trying to prevent and eradicate pests.
"When the application of pesticides is necessary for the safety and quality of the food produced, we go to a great extent making sure there is no impact to our neighbors in the surrounding communities," he said in a news release. "This also shows the educational efforts of our 'Spray Safe' program is working here in Kern County."
The study covered the period from Feb. 1 to Dec. 31 of last year. The Shafter monitoring station is located near a city well by Shafter High School. The other test sites were outside Kern County, in Salinas and Ripon.
The department said it decided which chemicals to test for based on how often they are used and the health risks they present. The list includes six fumigants and 11 organophosphates, which attack the nervous system and are more dangerous as exposure increases.
In the Shafter testing, eight pesticides and breakdown products -- acrolein, chlorpyrifos, chlorpyrifos OA, diazinon, diazinon OA, EPTC, methyl bromide and MITC -- were detected at concentrations greater than trace levels. Twelve other pesticides and breakdown products were found to be present at trace levels. The remaining chemicals were not detected.
Excluding acrolein, the chemicals diazinon and diazinon OA had by far the highest one-day concentrations relative to the level considered dangerous. Diazinon's one-day peak was found to be about 54 percent below the safety threshold; for diazinon OA, the one-day peak was about 72 percent below the threshold.
The department, part of the California Environmental Protection Agency, said it set the thresholds based not on enforceable limits but as guideposts for preliminary evaluation of data.
The air monitoring network was established in 2011 to broaden the state's knowledge of potential health risks from long-term pesticide exposure.