Food Safety:

FDA and USDA Should Strengthen Pesticide Residue Monitoring Programs and Further Disclose Monitoring Limitations

GAO-15-38: Published: Oct 7, 2014. Publicly Released: Nov 6, 2014.

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What GAO Found

The Food and Drug Administration's (FDA) most recent data from 2008 through 2012 show that pesticide residue violation rates in 10 selected fruits and vegetables were low, but FDA's approach to monitoring for violations, which targets commodities it has identified as high risk, has limitations. Among other things, GAO found that FDA tests relatively few targeted (i.e., non-generalizable) samples for pesticide residues. For example, in 2012, FDA tested less than one-tenth of 1 percent of imported shipments. Further, FDA does not disclose in its annual monitoring reports that it does not test for several commonly used pesticides with an Environmental Protection Agency (EPA) established tolerance (the maximum amount of a pesticide residue that is allowed to remain on or in a food)—including glyphosate, the most used agricultural pesticide. Although FDA is not required by law to select particular commodities for sampling or test for specific pesticides, disclosing this limitation would help meet Office of Management and Budget (OMB) best practices for conducting and reporting data collection and help users of the reports interpret the data. Also, FDA does not use statistically valid methods consistent with OMB standards to collect national information on the incidence and level of pesticide residues. FDA officials said that it would be costly to calculate national estimates for the foods it regulates because it would require a large number of samples for a wide array of products, but did not provide documentation on the cost of doing so or an assessment of the trade-offs of doing less targeting and more random sampling. Limitations in FDA's methodology hamper its ability to determine the national incidence and level of pesticide residues in the foods it regulates, one of its stated objectives.

For domestic and imported meat, poultry, and processed egg products, the U.S. Department of Agriculture's (USDA) Food Safety and Inspection Service's (FSIS) most recent available data from 2000 through 2011 show the agency found a low rate of pesticide residue violations, but its data had limitations. Specifically, for this period, FSIS did not test meat, poultry, and processed egg products for all pesticides with established EPA tolerance levels. Like FDA, FSIS is not required by law to test the foods it samples for specific pesticides, but disclosing this limitation in annual reports would meet OMB reporting best practices. Since 2011, FSIS has increased the number of pesticides it has tested for and samples it has taken and engaged with EPA on changes to FSIS's monitoring program to better provide EPA with data it needs to assess the risks of pesticides.

The most recent data from USDA's Agricultural Marketing Service's (AMS) annual survey of highly consumed commodities, including fruits and vegetables, show that, from 1998 through 2012, pesticide residue detections varied by commodity and were generally well below tolerance levels. EPA and others praise AMS's data collection efforts as providing valuable information on the incidence and level of pesticide residues in foods. In addition, while the sampling methodology used by AMS in the Pesticide Data Program meets many of OMB's best practices for conducting and releasing information to the public concerning a data collection effort, it does not meet several others, such as some principles of probability sampling that are important for ensuring that the data the agency collects are nationally representative. As AMS does not disclose these limitations in its annual monitoring reports, users of the data may misinterpret information in these reports and draw erroneous conclusions based on the data.

Why GAO Did This Study

From 1970 to 2007, hundreds of millions of pounds of pesticides were applied annually to U.S. food crops to protect them from pests. To protect consumers, EPA sets standards—known as tolerances—for pesticide residues on foods. FSIS monitors meat, poultry, and processed egg products to ensure they do not violate EPA's tolerances, and FDA monitors other foods, including fruits and vegetables. AMS gathers annual residue data for highly consumed foods, although not for enforcement purposes.

GAO was asked to review federal oversight of pesticide residues in food. This report examines (1) what FDA data show with respect to pesticide residue violations in the foods that it regulates; (2) what FSIS data show with respect to pesticide residue violations in the foods that it regulates; and (3) what AMS data show with respect to pesticide residue levels in fruits and vegetables. For each agency, GAO examined limitations, if any, in the agencies' monitoring of foods for pesticide residues. GAO analyzed FDA, FSIS, and AMS pesticide residue data, including their reliability, reviewed agency methods for sampling foods for testing, and interviewed agency officials.

What GAO Recommends

GAO recommends that FDA improve its methodology and FDA and USDA disclose limitations in their monitoring and data collection efforts. FDA said it will consider methodological changes and will disclose limitations. USDA agreed with GAO's recommendations.

For more information, contact John Neumann at (202) 512-3841 or neumannj@gao.gov.

Recommendations for Executive Action

  1. Status: Open

    Priority recommendation

    Comments: In July 2019, FDA said that the recommendation should be closed as not implemented. FDA said that it remained concerned that the disclosure of pesticides for which FDA does not test would enable users to more easily circumvent the pesticide monitoring program, which could jeopardize public health and, at a minimum, would undermine FDA's law enforcement efforts. In addition, FDA said that it discloses in its annual reports all pesticides tested for within the reports' annual scope as required by the Pesticide Monitoring Improvements Act of 1988. FDA's annual reports also clarify that not all pesticides for which EPA has established tolerances were analyzed. FDA said that the Pesticide Monitoring Improvements Act of 1988 does not specifically direct the agency to report information on untested pesticides with EPA-established tolerances. We continue to believe that disclosing the pesticides that are not included in FDA's testing program would be consistent with OMB best practices for reporting limitations relevant to analyzing and interpreting results from a data collection effort. In particular, we continue to believe that FDA should be more transparent about the potential effect of not testing for all pesticides for which EPA has established tolerances. We also note that the Department of Agriculture's Food Safety and Inspection Service implemented a similar recommendation to disclose information about its pesticide monitoring program. As a result, we are keeping this recommendation open.

    Recommendation: To better inform users of the annual monitoring report about the frequency and scope of pesticide tolerance violations, the Secretary of Health and Human Services should direct the Commissioner of FDA to disclose in the agency's annual pesticide monitoring program report which pesticides with EPA-established tolerances the agency did not test for in its pesticide monitoring program and the potential effect of not testing for those pesticides.

    Agency Affected: Department of Health and Human Services

  2. Status: Closed - Not Implemented

    Comments: In July 2019, FDA said that we should close the recommendation as not implemented. FDA said that it has assessed the feasibility associated with a statistically valid sampling methodology as we recommended and concluded that the agency would have to invest substantial resources to conduct the analysis necessary to achieve sufficient precision for each food-pesticide combination. Such a resource commitment, according to FDA, would impact the availability of funding for competing priorities. We conclude from FDA's July 2019 statement that the agency does not plan to design and implement a statistically valid sampling methodology as we recommended. Our recommendation also included a provision calling for FDA, if it did not implement a method to gather nationally representative data on pesticide residue, to justify statistically the use of a nonprobability method that can measure the estimation error. In July 2019, FDA said that it was not aware of any method that could measure estimation error when applied solely to a nonprobability sample, absent either knowing the true incidence rate or having a probability sample for comparison. We continue to believe that FDA should implement our recommendation. However, in light of FDA's statements, we have closed the recommendation as not implemented.

    Recommendation: To gather and report reliable, nationally representative data on pesticide residue violations, the Secretary of Health and Human Services should direct the Commissioner of FDA to design and implement a statistically valid sampling methodology that would enable the agency, within existing resources, to gather nationally representative pesticide residue incidence and level data for both domestically produced and imported foods, or justify statistically the use of a nonprobability method that can measure the estimation error. In designing either approach, FDA should consider the extent to which the benefits exceed the costs.

    Agency Affected: Department of Health and Human Services

  3. Status: Closed - Not Implemented

    Comments: In our report, we said that one of the objectives of FDA's pesticide monitoring program is to determine the incidence and level of pesticide residues in domestic and imported foods. We concluded, however, that FDA did not use statistically valid methods consistent with Office of Management and Budget standards to collect national information on the incidence and level of pesticide residues. In July 2019, FDA said that we should close this recommendation as not implemented. Specifically, FDA said that its pesticide monitoring program is targeted in nature; the agency does not conduct nationally representative incidence and level monitoring on a routine basis. Rather, USDA leverages data from USDA's Pesticide Data Program, which FDA stated is a national statistically valid sampling program. FDA does disclose in its annual pesticide monitoring reports that monitoring is not statistically based. Specifically, FDA states that its monitoring "is not random or statistically designed; rather, emphasis is given to the sampling of commodities most frequently consumed or imported, commodities and places of origin with a history of violations, and to a lesser extent, larger-size shipments." Furthermore, FDA states in its annual reports that "considering the above and available Agency resources, FDA has not attempted to develop a monitoring program that would be statistically based. The current pesticide sampling program, coupled with broad-based enforcement strategies for imports, allows FDA to achieve the program's main objective of consumer protection." In July 2019, FDA said that it will continue to include similar statements in future annual reports. However, we reported USDA's Pesticide Data Program had characteristics that affected its use in evaluating the effectiveness of FDA's targeted pesticide monitoring program. In our view, FDA's focus on targeted samples limits the agency's ability to make valid national estimates about violation rates for imported and domestic foods since the targeted samples it collects cannot be the basis of statistically valid national estimates. Thus, we continue to believe that FDA should fully implement this recommendation. However, in light of FDA's July 2019 statements, we have concluded to close the recommendation as not implemented.

    Recommendation: To gather and report reliable, nationally representative data on pesticide residue violations, the Secretary of Health and Human Services should direct the Commissioner of FDA to report the nationally representative incidence and level data in its annual pesticide monitoring reports, including disclosing the limits of its chosen sampling methodology.

    Agency Affected: Department of Health and Human Services

  4. Status: Closed - Not Implemented

    Comments: We reported that one of the objectives of FDA's pesticide monitoring program is to determine the incidence and level of pesticide residues in domestic and imported foods. Having incidence and level data would enable FDA to assess the effectiveness of its targeted pesticide compliance and enforcement monitoring program. We concluded that FDA did not use statistically valid methods consistent with Office of Management and Budget standards to collect national information on the incidence and level of pesticide residues. FDA stated in July 2019 that the agency does not conduct nationally representative incidence and level monitoring on a routine basis. Therefore, FDA said that the recommendation should be closed as not implemented. FDA's July 2019 statement said that HHS believes that monitoring the effectiveness of FDA's targeted pesticide compliance and enforcement monitoring program is important. According to the agency's statement, FDA uses a variety of sources of information to evaluate the effectiveness of its targeted monitoring program. However, we continue to believe that a comprehensive evaluation cannot be successfully completed without statistically valid data on the national incidence and level of pesticide residues. Therefore, in light of FDA's statements, we have concluded to close the recommendation as not implemented.

    Recommendation: To evaluate and refine its targeted pesticide compliance and enforcement monitoring program, the Secretary of Health and Human Services should direct the Commissioner of FDA to use the incidence and level data to assess the effectiveness of FDA's targeted pesticide compliance and enforcement monitoring program, including its use of the Predictive Risk-based Evaluation for Dynamic Import Compliance Targeting targeting tool for imported foods, by comparing the rate of violations detected through the program to the overall rate of pesticide residue violations within the domestic and imported food supplies.

    Agency Affected: Department of Health and Human Services

  5. Status: Closed - Not Implemented

    Comments: In July 2019, FDA officials told us that the agency generally concurs with this recommendation and that FDA continually evaluates and refines its target monitoring programs by identifying foods that are at high risk for pesticide residue violations. According to FDA officials, the agency modifies its sampling plans each year and conducts special sampling assignments, as necessary, based on information on foods that are high risk. FDA provided several examples of its efforts to identify foods that it should monitor, including analysis of U.S. food consumption data and pesticide use data from the United States and other countries. We acknowledge that FDA uses a variety of methods to identify foods that are at high risk for pesticide residue violations. However, as we stated in GAO-15-38, we do not believe that FDA can be sure that it is targeting high risk commodities without statistically valid data on the incidence and level of violations in commodities. And, as we discuss in our status comments on other recommendations to FDA in this report, the agency does not collect such data. Therefore, we have closed this recommendation as not implemented.

    Recommendation: To evaluate and refine its targeted pesticide compliance and enforcement monitoring program, the Secretary of Health and Human Services should direct the Commissioner of FDA to identify any types of domestic and imported foods that are at high risk for pesticide residue tolerance violations to improve the ability of its targeted pesticide compliance and enforcement monitoring program to consistently identify food likely to have violations.

    Agency Affected: Department of Health and Human Services

  6. Status: Closed - Implemented

    Comments: FSIS has taken actions that are responsive to our recommendation. FSIS's National Residue Program sampling plan includes a relative risk analysis of what the agency has described as a comprehensive list of pesticides used domestically and internationally that includes all pesticides with tolerances established by EPA for FSIS-regulated products. FSIS assessed the pesticides' relative risks using 4 characteristics related to exposure and toxicity. FSIS provided a draft of its Fiscal Year 2020 sampling to us in July 2019, which shows the agency's relative risk ranking of 481 pesticides. The draft plan identifies which of the 481 pesticides FSIS will include in its monitoring program and which it will not. In particular, the draft plan states that FSIS will test for 108 of the pesticides but not test for the remaining 373 pesticides. With these statements, FSIS has met the intent of the first part of our recommendation by disclosing which pesticides, including those with EPA-established tolerances, are not included in its monitoring program. FSIS also states in its draft sampling plan for Fiscal Year 2020 that it does not currently test for some of the pesticides that are at the top of the agency's relative risk ranking. In addition, FSIS notes that by not testing for those pesticides, the agency does not know the extent to which exposures to those pesticides occur in the foods that FSIS regulates. With these statements, in combination with its list of pesticides that are included and not included in its monitoring program, FSIS has responded to the second part of our recommendation to disclose the potential effect of not testing for all pesticides with EPA-established tolerances. In particular, FSIS's sampling plan makes clear to the public that the agency does not know the extent to which consumers of the foods that FSIS regulates are exposed to pesticides that, according to FSIS's risk analysis, could be considered of higher concern to public health. We have closed the recommendation as implemented on the basis of these actions by FSIS.

    Recommendation: To better inform the public about the frequency and scope of pesticide tolerance violations, the Secretary of Agriculture should direct the FSIS Administrator to disclose in the agency's annual pesticide monitoring program report which pesticides with EPA-established tolerances the agency did not test for in its National Residue Program and the potential effect of not testing for those pesticides.

    Agency Affected: Department of Agriculture

  7. Status: Closed - Not Implemented

    Comments: The Agricultural Marketing Service (AMS) published its 2017 Pesticide Data Program annual report in December 2018. As with earlier reports, this report does not provide sufficient documentation of the survey methods used in the program. In particular, the report does not provide complete information on the sampling methodology the agency used, such as how it identified and selected states, food distribution centers, and commodities for pesticide residue testing. AMS did include measures of sampling error for one commodity/pesticide combination. However, AMS did not explain how or why it selected that particular commodity/pesticide combination for its analysis of sampling error. Likewise, AMS did not explain the significance of the sampling error that it found, either with respect to that commodity/pesticide combination or for other combinations. Therefore, AMS has not fully implemented the recommendation and we have closed this recommendation as not implemented.

    Recommendation: To better meet federal standards and best practices for statistical surveys, the Secretary of Agriculture should direct the AMS Administrator to provide better documentation of the survey methods used in its Pesticide Data Program in the program's annual reports by providing more complete information on the sampling methodology the agency uses, such as how it identifies and selects states, food distribution centers, and commodities for pesticide residue testing, and include measures of sampling error for reported estimates.

    Agency Affected: Department of Agriculture

  8. Status: Closed - Not Implemented

    Comments: The Agricultural Marketing Service (AMS) published its 2016 Pesticide Data Program annual report in February 2018 and its 2017 annual report in December 2018. These reports have a new section titled Sampling Limitations. In that section, the agency acknowledges that the total number of distribution centers and terminal markets within the participating states is difficult to establish because existing sites may go out of business or merge and new sites may open during the course of the year. Despite this limitation, the agency concludes that the sites selected in the program are representative of all sites in these states. However, the agency has not provided sufficient documentation in the report to support the claim that its data are representative of conditions across the country for commodities in the U.S. food supply. Therefore, AMS has not fully implemented the recommendation and we have closed the recommendation as not implemented.

    Recommendation: To better meet federal standards and best practices for statistical surveys, the Secretary of Agriculture should direct the AMS Administrator to provide better documentation of the survey methods used in its Pesticide Data Program in the program's annual reports by reporting on the extent to which its survey covers commodities in the U.S. food supply and any limitations associated with its survey methodology.

    Agency Affected: Department of Agriculture

  9. Status: Closed - Not Implemented

    Comments: The Agricultural Marketing Service (AMS) published its 2017 Pesticide Data Program annual report in December 2018. The report does not describe methods users should employ to analyze the data, including obtaining margins of error for making generalizable estimates of pesticide residues in commodities. Similarly, AMS's website, which contains the annual report and associated documentation such as the data dictionary, does not describe methods users should employ to analyze the data. Therefore, AMS has not implemented the recommendation and we have closed the recommendation as not implemented.

    Recommendation: To better meet federal standards and best practices for statistical surveys, the Secretary of Agriculture should direct the AMS Administrator to provide better documentation of the survey methods used in its Pesticide Data Program in the program's annual reports by describing methods users should employ to analyze the data, including obtaining margins of error for making generalizeable estimates of pesticide residues in commodities.

    Agency Affected: Department of Agriculture

 

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