The majority of fresh produce samples collected by the California Department of Pesticide Regulation (DPR) in 2011 had no detectable pesticide residues, and residues that were detected generally fell well below allowable limits to protect public health, DPR Director Brian R. Leahy announced.

Of the 2,707 samples of more than 160 types of domestic and imported produce analyzed for pesticide residues in 2011:

● 60.8 percent (1,647 samples) had no pesticide residues detected.

● 35.8 percent (968) had residues within the allowable limits set by the U.S. Environmental Protection Agency (U.S. EPA).

● 3.4 percent (92) had illegal residues. Although illegal, the residues were at such low levels they posed no acute health risk. Most of the samples with illegal residues were imported from other countries.

Of the total samples, 988 were of California-grown produce of which 97.9 percent were in compliance with the allowable limits.

“Our scientists collect produce samples from large grocery stores, mom-and-pop shops and wholesale outlets throughout the state,” Leahy said. “In addition to most frequently consumed fruits and vegetables like apples and lettuce, we sample tomatillos and other produce used in ethnic cooking. An overall compliance rate of 96 percent - nearly 98 percent for California-grown produce - is good news for farmers and consumers.”

Nearly 25 percent of the 2011 results were analyzed by new technology that expands the number of pesticides detected, including recently registered pesticides. DPR is committed to fully implementing this new technology by 2014 to ensure that fresh produce sold in California is in compliance with pesticide safety standards.

The new technology, known as liquid chromatography mass spectrometry (LC/MS), initially was used to screen some DPR produce samples in a 2009 pilot project at the California Department of Food and Agriculture (CDFA) Center for Analytical Chemistry in Sacramento. In the 2011-12 fiscal year, DPR increased its funding to CDFA to expand LC/MS screening. The cost is covered by a special fund generated by fees on sales of pesticides used in California and registration and license fees.

DPR contracts with CDFA for laboratory services, including analyzing produce for illegal pesticide residues; testing air, ground and water monitoring samples; and analyzing samples collected for enforcement and illness investigations.

In 2011, 449 of the produce samples collected were analyzed using both LC/MS and the old multiresidue screens. Of those, 78 percent (350) had residues only detectable by LC/MS. More than 97 percent of the residues detected by LC/MS were within allowable limits.

“We anticipated finding more pesticide residues with LC/MS because the older technology is designed to detect older pesticides like organophosphates that are being replaced by more benign pest control products,” Leahy said. “We want to emphasize that most produce has no detectable pesticide residues and when there are residues, they are at such a low level they are not a health risk.”

Only eight kinds of produce were analyzed with LC/MS in 2011: apples, celery, kale, Chinese long beans, potatoes, strawberries, peaches and spinach. All produce collected by DPR will eventually be screened by the new technology as it is phased in at both CDFA laboratories.

When illegal residues are found, DPR immediately removes the produce from sale. For example, an illegal pesticide residue on a peach sample analyzed by the new technology led to more than 2.4 million pounds of peaches removed from the market. As a follow-up to this case, DPR took enforcement action earlier this year against two San Joaquin Valley pesticide dealers for a total of $105,000 for knowingly selling a pesticide product for a use not allowed by the label.

California has been analyzing produce for pesticide residues since 1926. Leahy noted that DPR’s residue monitoring is the most extensive program of its kind in the nation. It is the last check in a comprehensive enforcement program that begins with a thorough evaluation to ensure only those pesticides that are effective and can be used safely with no adverse effects to human health or the environment are registered.

In 2010 and 2011 combined, DPR detected illegal pesticide residues most frequently on snow peas from Guatemala; tomatillos, chili peppers, limes and papaya from Mexico; ginger from China; and spinach and kale from California.

The 2011 pesticide residue monitoring data and previous years are posted at: http://www.cdpr.ca.gov/docs/enforce/residue/rsmonmnu.htm.

A fact sheet, “Pesticides and food: how we test for safety,” which includes information about how consumers can reduce exposure to pesticides in food, is posted at: http://www.cdpr.ca.gov/docs/dept/factshts/residu2.pdf.