2007 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 State Residue Monitoring Program (previously known as the Marketplace Surveillance Program).

Residue Monitoring via the California State Residue Monitoring Program

(previously known as the Marketplace Surveillance Program)

The Department of Pesticide Regulation’s (DPR) California State Residue Monitoring Program is one of the most extensive state residue-monitoring programs 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 State Residue Monitoring Program results from 2007

In 2007, DPR collected 3,562 samples of more than 100 kinds of commodities. All 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.

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, 60.8 percent were domestic, 38.7 percent were imported, and 0.5 percent were of undetermined origin.

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

  • 62.6 percent of samples had no pesticide residues detected.
  • 36.2 percent of samples had residues that were within the legal tolerance levels.
  • 1.2 percent of samples had illegal residues. A produce item with an illegal residue level does not necessarily indicate a health hazard.

Residues within tolerance were found in 36.2 percent of the 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 1.2 percent of samples. Of these, 0.1 percent had residues that were over the tolerance level, and 1.1 percent had residues of a pesticide not authorized for use on the commodity (no tolerance established). Please note: Numbers may not add up to 100 percent due to rounding.

In 2007, as in several recent years, certain commodities produced in certain locations had a higher proportion of samples with illegal residues:

commodity and origin location percent of samples with illegal residues
Commodity and origin
% of samples with illegal residues
(2006 and 2007 combined)
Snow peas produced in Guatemala 51.4 % (19 of 37 samples)
Ginger produced in China 7.8 % (5 of 64 samples)
Bok choy produced in California 6.8 % (3 of 44 samples)
Peppers produced in Mexico 4.4 % (22 of 502 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.

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 2007 are available for downloading on DPR’s Web site, www.cdpr.ca.gov, click on "A-Z Index" and then "Residue Monitoring Program."