For the second year in a row, Department of Pesticide Regulation (DPR) air monitoring in various California rural agricultural communities including Santa Maria shows nearly three dozen pesticides have residue levels well below those established to protect human health and the environment.
“This is reassuring news for residents,” DPR Director Brian Leahy said. “Our monitoring in 2012 shows that none of the pesticides exceeded their screening levels, indicating a low health risk to the people in these communities. These findings indicate that the state and county restrictions are keeping air concentrations below the health protective targets set by DPR.”
In 2012, as part of its statewide air-monitoring effort, DPR monitored 33 pesticides and five pesticide breakdown products in three California communities: Salinas (Monterey County), Shafter (Kern County) and Ripon (San Joaquin County).
These communities, part of the department’s air-monitoring network (AMN), were selected from a list of 226 communities based on pesticide use on surrounding farmland and demographics, including the percentage of children, the elderly and farm workers in the local population.
The pesticides were selected based on their potential health risks and the amount used. They include methyl bromide and chlorpyrifos. Results released Wednesday also include methyl bromide concentrations monitored by Air Resources Board stations in Oxnard (Ventura County), Santa Maria (Santa Barbara County) and near Watsonville (Monterey County) at DPR’s request.
A total of 369 samples were collected from all six sampling locations for the 2012 calendar year. The Camarillo/Oxnard, Santa Maria and Watsonville sampling locations were part of the pesticide study conducted by ARB while the Salinas, Shafter and Ripon sampling locations were part of the AMN. Samples from all six sites were collected from Jan. 1 through Dec. 31, 2012.
Of the 369 samples, 289 (78.3 percent) contained no detectable amount and were below the LOQ (limit of quantification — not quantifiable). Of the 369 samples, 80 (21.7 percent) contained detections above the LOQ (quantifiable).
Overall, the AMN 2012 report found that 94.5 percent of the 6,002 analyses resulted in no detectable concentrations.
No locations exceeded the screening levels for the chronic exposure period for methyl bromide. The highest overall average concentration measured was 0.13 ppb at Watsonville. Camarillo had the second highest one-year average concentration of 0.10 ppb.
All five locations (Camarillo, Ripon, Santa Maria, Salinas and Shafter) that had sampling results for both 2011 and 2012 had lower yearly average concentrations in 2012 compared to 2011.
Other key findings include:
n For 2012, all measured pesticide air concentrations were less than DPR’s regulatory targets or screening level.
n Of the 33 pesticides and five breakdown products that were monitored, 14 could not be detected at all and 13 were only detected at trace levels.
n The pesticides detected the most often were chlorpyrifos and MITC. Both were found at all three locations 28 percent of the time, at air concentrations that were low relative to the screening levels.
No state or federal agency has established health standards for pesticides in air. Therefore, DPR developed health-screening levels for the monitored pesticides to place the results in a health-based context.
“The data helps DPR to determine whether our restrictions on pesticide applications protect people and the environment in the long term,” Leahy said.
California is the only state that monitors air as part of its continuous reevaluation of pesticides to ensure the protection of workers, public health and the environment. This includes conducting field studies to monitor exposure to workers and to measure how pesticides move and break down in air, soil and water.
DPR uses this information to decide if further regulatory measures are necessary.
The department’s air-monitoring network was established to expand its knowledge of the potential health risks of long-term exposure to pesticides. DPR scientists sought more accurate estimates of health risks based on long-term exposure rather than extrapolation from short-term monitoring data to help them determine if additional protective measures are needed.