A Scientific Advisory Panel is questioning EPA’s proposed use of a controversial Columbia University epidemiological study as the basis for a decision on whether to cancel pesticide registrations.
The SAP, which was convened by EPA back on April 19-21, referred specifically to the continued registration of chlorpyrifos, which is sold under the trade name Lorsban. But farm and farm input organizations are criticizing the potential use of the study on other pesticides.
Among those are atrazine and glyphosate, which will be the subject of a Federal Insecticide, Fungicide and Rodenticide Act Scientific Advisory Panel Review in Washington on Oct. 18-21. EPA appears to be seeking scientists with backgrounds in cancer research for the panel rather than crop protection.
“We see yet again, in the minutes submitted to EPA by the (chlorpyrifos) SAP, that the panelists question EPA’s shift to the use of certain epidemiological study outcomes, rather than toxicological data, in human health risk assessments,” said Jay Vroom, president and CEO of CropLife America.
Vroom was commenting on EPA’s release of the minutes from the Scientific Advisory Panel on April 19-21. The minutes are included in a 77-page report titled “Chlorpyrifos: Analysis of Biomonitoring Data.” (CropLife America represents the nation’s pesticide manufacturers.)
A resounding ‘no’
“In our written comments submitted to the SAP, we specifically asked panelists to examine the question, ‘Can these epidemiological studies be appropriately used for quantitative risk assessment purposes?’” said Vroom. “The answer is loud and clear – a resounding no. The crop protection industry now calls on EPA to base regulatory decision-making on hard toxicological data.”
The epidemiological study in question was published by the Columbia Center for Children’s Environmental Health. Unlike most scientific studies, the authors have declined to provide all of the report’s data so that it could be reviewed by their peers in the research community.
Among the highlights of the chlorpyrifos SAP’s minutes, according to CropLife America’s review:
- The SAP agrees with EPA that applying additional safety factors to the existing point of departure to account for a potential new mode of action would be problematic due to the challenges in justifying any particular value for such an adjustment;
- Some SAP members stated that the sample size may have limited the CCCEH study’s ability to examine the association of chlorpyrifos blood concentration on neurodevelopment in more vulnerable populations; and
- With respect to fetal exposure, the Panel noted that much uncertainty in the use of cord blood as a measure would be removed if the raw data from CCCEH were provided for reanalysis.
Lack of agreement
“We applaud the report of the SAP as the majority of the panel did not agree with the EPA’s use of the results from a single longitudinal study to make a decision based on the use of cord blood measures of chlorpyrifos to initiate risk assessment,” said Janet Collins, senior vice president of science and regulatory affairs at CLA.
“These (Columbia Center for Children’s Environmental Health) epidemiological studies were not designed to demonstrate cause of any human health impact and the effects of exposure to a single compound.” Dr. Collins noted.
“We further applaud the SAP in its determination the panel did not have confidence that the CCCEH analytical data could accurately be used in quantitative risk assessment as a point of departure, due to the many uncertainties that cannot be clarified, since the raw data are not available for verification or validation of the analytical data. CLA has maintained for years that epidemiological data have an important role for EPA in decision making, but that the CCCEH study and EPA’s various considered uses of it do not serve a human health purpose.”
Members of Congress have been questioning EPA’s intent in lining up members of the October Scientific Advisory Panel review for glyphosate and criticizing the agency for failing to “mention or support the final report prepared by its own Cancer Assessment Review Committee.”
The latter was a reference to a report that appeared on the EPA’s website in mid-April and then removed 24 hours later after EPA Administrator Gina McCarthy said it did not represent EPA’s final assessment. The report had said glyphosate was “not likely to be a carcinogen.”
House Science Committee Chairman Lamar Smith, R-Texas, one of the most vocal critics of the agency’s removal of the Cancer Assessment Review Committee report, issued a statement critical of EPA’s actions in establishing the glyphosate SAP.
“The Science Committee continues to find evidence that EPA fails to recognize or acknowledge the final and complete science that its own agency conducts and instead appears to make politically motivated decisions,” Smith said.
“EPA has failed to provide the (House Science) committee with a single document responsive to its oversight request on this subject. The committee will continue to pursue its oversight efforts on this matter to ensure that EPA is using sound science.”
The National Corn Growers Association, meanwhile, has voiced similar criticism of EPA’s handling of its review of atrazine, one of the most commonly used corn and grain sorghum herbicides in the world.