The latest air monitoring results released from the California Department of Pesticide Regulation (DPR) show that, for the second year in a row, all pesticides monitored were found below levels that could indicate a health concern or need for further evaluation.

Highlights of the 2016 draft air monitoring report shows that of the 37 chemicals (32 pesticides and five breakdown products) that are monitored:

Table 5 lists the number of detections for each pesticide and pesticide breakdown products included in the network. The chemicals with the highest number of detections were carbon disulfide (91 percent), chlorothalonil (44 percent, 1,3-dichloropropene (36 percent, chlorthaldimethyl (DCPA) (28 percent), chlorpyrifos oxygen analog (22%), and MITC (22%).

After 2016, the network will no longer monitor for concentrations of carbon. There are no current registered pesticide products that contain carbon disulfide or sodium tetrathiocarbonate (which degrades to carbon disulfide) as its active ingredient and any carbon disulfide detection is most likely due to combustion of fossil fuels plus use as an industrial solvent and its release from manufacturing and processing facilities.

Carbon disulfide is also a product of the anaerobic decomposition of vegetation with several natural sources including wetlands, oceans, and volcanoes.

“Air monitoring is an important tool used to ensure that the California’s vigorous pesticide regulatory program is working to protect human health as legal pesticides are applied to produce food and fiber” said DPR Director Brian Leahy.

California is the only state that monitors air as part of its continuous re-evaluation of pesticides to ensure the protection of workers, public health and the environment. The pesticides monitored were selected based primarily on the potential risk to human health. They include all major fumigants and many organophosphates.

As part of the air monitoring network, DPR monitors and analyzes pesticides in three communities: Salinas, Shafter and Ripon.

Additionally, the California Air Resources Board, at DPR’s request, monitors for three fumigant pesticides in three other communities: Ventura, Santa Maria and Watsonville.

The state’s air-monitoring network is the first of its kind in the nation. It was created in 2011 to expand DPR’s knowledge of long-term exposure to pesticides. The data from the network helps DPR determine if additional protective measures are needed.

DPR recently expanded the air-monitoring network in order to obtain more data from more locations. Eight locations will monitor 31 pesticides and five pesticide breakdown products at the sites for two more years.

Those new locations include sites in San Joaquin, Cuyama and Lindsay. The Ripon site near city hall will no longer be used.

At the end of this period, DPR will evaluate and determine the need and scope for the air-monitoring network.