2008 Pesticide Residues in Fresh Produce


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About California’s Pesticide Regulatory Program

California has the nation’s most comprehensive program to regulate pesticide use. Under this program:

  • A pesticide’s safety and efficacy is evaluated before it is allowed to be used.
  • All agricultural pesticide use must be reported.
  • Pesticide specialists and environmental scientists enforce restrictions intended to ensure the proper and safe use of pesticides.
  • Domestic and imported produce are sampled and tested for pesticide residues via the California Pesticide Residue Monitoring Program (previously known as the Marketplace Surveillance Program).

Residue Monitoring via the California Pesticide Residue Monitoring Program

(previously known as the Marketplace Surveillance Program)

The Department of Pesticide Regulation’s (DPR) California Pesticide Residue Monitoring Program is the most extensive state residue-monitoring program in the nation. It is the final check in an integrated network of programs designed to protect human health and the environment. The Residue Monitoring Program is designed to meet the following goals:

  1. Monitor pesticide residues in raw agricultural commodities throughout the California food supply. DPR samples commonly consumed commodities, giving special emphasis to commodities consumed by infants and children, and pesticides listed as causing cancer or reproductive toxicity.

    In addition, in accordance with DPR’s commitment to environmental justice, we select commodities and sampling locations to reflect differences in consumption patterns among ethnic and socioeconomic groups.

  2. Identify specific commodities that have a higher incidence of illegal residues. DPR usually increases sampling of commodities that have a history of higher incidence of illegal residues, to better understand the extent of the problem.
  3. Help bring sources of illegal residues into compliance. To determine how commodities with illegal residues enter the channels of trade, DPR sometimes focuses on specific distributors or specific brand names.
  4. Generate data requested by DPR’s Medical Toxicology Branch while they conduct risk assessments of particular pesticides.

The findings have been consistent over the years: the majority of produce samples have had no pesticide residues detected, and pesticide detections in produce are generally well below the allowable tolerances. A "tolerance" is the highest residue level of a particular pesticide that is legally allowed on a particular commodity. Tolerances for a pesticide are set by the U.S. Environmental Protection Agency (U.S. EPA) based on the potential risks to human health posed by that pesticide.

California Pesticide Residue Monitoring Program results from 2008

In 2008, DPR collected 3,483 samples of more than 140 kinds of commodities. All sampled commodities were derived from plants (no animal products) and were raw (not processed). Sampling of processed foods is the responsibility of the federal Food and Drug Administration (FDA) and U.S. Department of Agriculture (USDA).

Samples were collected throughout the channels of trade, including wholesale and retail outlets, distribution centers, and farmers markets. Both domestic and imported produce were monitored. Of the total samples, 55.4 % were domestic (1,930 of 3,483 samples), 43.3 % were imported (1,508 of 3,483 samples), and 1.3 % were of undetermined origin (45 of 3,483 samples).

All samples were tested in analytical laboratories using multiresidue screens capable of detecting more than 200 pesticides and breakdown products. The results:

  • 70.2 % of samples had no pesticide residues detected (2,444 of 3,483 samples).
  • 28.7 % of samples had residues that were within the legal tolerance levels (999 of 3,483 samples).
  • 1.1 % of samples had illegal residues (40 of 3,483 samples). A produce item with an illegal residue level does not necessarily indicate a health hazard.

Residues within tolerance were found in 28.7 % of the samples (999 of 3,483 samples). As in recent years, the majority of these samples had residues at less than 10 percent of the tolerance level. Illegal residues were found in only 1.1 % of samples (40 of 3,483 samples). Of these, 2.5% (1 of 40 illegal samples) had residues that were over the tolerance level, and 97.5 % (39 of 40 illegal samples) had residues of a pesticide not authorized for use on the commodity (no tolerance established). Please note: Percentages may not add up to 100 % due to rounding.

In 2008, as in several recent years, certain commodities produced in certain locations had a higher proportion of samples with illegal residues:

Commodity and origin % of samples with illegal residues
(2007 and 2008 combined)
Snow peas produced in Guatemala 21.7 % (10 of 46 samples)
Chili peppers produced in Mexico 10.4 % (17 of 163 samples)
Papayas produced in Mexico 10.0 % (4 of 40 samples)
Ginger produced in China 5.3 % (9 of 171 samples)
Bok choy produced in California 4.7 % (4 of 86 samples)

Although illegal, most of these residues were at very low levels (a fraction of a part per million). Nonetheless, when illegal residues are found, DPR reacts immediately by removing the illegal produce from sale, then verifies that the produce is either destroyed or returned to its source. In addition, if the owner of the produce has similar produce from the same source, DPR quarantines that produce until the laboratory verifies that it is free from illegal residues. Further, DPR traces the distribution of the illegal produce by contacting distributors throughout California, imposing additional quarantines and conducting additional sampling as needed.

In addition, DPR is actively working with partners including the federal Food and Drug Administration (FDA) and federal Immigration and Customs Enforcement (ICE) to identify and eliminate sources of illegal residues. We also collaborate with trade organizations and farmer-training projects, encouraging them to educate producers about pesticide residues in their commodities.

Significance of the Results

The validity of any sampling program lies in its design and in its ability to replicate the results. Over the past decade, even as the number of samples varied, the findings have been consistent from year to year. The majority of produce samples have no detectable pesticide residues. Residues that are found are usually at levels that are measured at a fraction of a part per million (ppm). In most years, approximately one percent of total samples have residues over the tolerance levels. Certain commodities produced in certain locations have a history of higher proportions of illegal residues.

While the goal of DPR’s regulatory program is to ensure that all food is in compliance with pesticide safety standards, a produce item with an illegal residue level does not necessarily indicate a health hazard. Each such incident, however, is evaluated for possible health concerns. The results from years of DPR residue monitoring document the overall safety of produce grown and consumed in California.

The data collected in 2008 are available for downloading on DPR’s Web site, www.cdpr.ca.gov, click on "A-Z Index" and then "Residue Monitoring Program."