EPA Chlorpyrifos Assessment: A Harbinger of Restricted Science Rule Havoc

September 25, 2020
Jeff Vanuga/NRCS
Genna Reed
Senior Analyst

For years, the EPA has been downplaying scientific findings in an attempt to continue the use of organophosphate insecticide, chlorpyrifos, which is a known neurotoxin and threatens the health of children, especially Latinx children who live near farmland or are the children of farmworkers. But now, it has chosen to inexplicably throw out studies from consideration as it approaches a critical registration decision.

Against the advice of its own scientists, in 2017, EPA scrapped a ban on the pesticide chlorpyrifos, a chemical so harmful that the EPA banned its use in homes in 2000 because of the risks posed to children’s health. Chlorpyrifos was derived from a class of chemicals used as nerve agents during World War II, and decades of scientific evidence now show that exposure to chlorpyrifos, even at low doses, can inhibit the normal development of children’s brains, beginning in the womb, and result in a higher risk of lowered IQ or autism.

But EPA dismissed that evidence, stating that “the science addressing neurodevelopmental effects remains unresolved” and that a further review of the science was needed.” This move was at odds with EPA’s own scientists and the scientific community, and the courts have agreed. In 2018 and 2019, federal courts ordered the EPA to finalize its ban on chlorpyrifos. However, the EPA continued to refuse, falsely claiming that there were not enough data to demonstrate that the pesticide is not safe. And now, EPA is applying the principles of its not yet finalized restricted science rule to justify removing key studies from a revised draft human health risk assessment of chlorpyrifos that will inform the agency’s upcoming decision on how chlorpyrifos will be used in the future.

EPA’s removal of Columbia study underscores dangers of its restricted science rule

The EPA’s proposed restricted science rule, as modified by the supplemental notice, would limit EPA’s use of science to studies where raw data could be made publicly available, or downweighting research otherwise. As required by law, the EPA must have access to the best available science to carry out its charges—but this rule would hinder the agency’s ability to use the best available science, because EPA relies frequently on studies with underlying data that cannot be made public, in order to protect personally identifying data and other sensitive information. That’s exactly what has occurred in EPA’s revised draft human health risk assessment for chlorpyrifos released this week.

The Columbia Center for Children’s Environmental Health (CCCEH), once partially funded by EPA, has conducted and published cohort studies showing that in utero exposure to the chemical was linked to negative neurodevelopmental impacts. The health data was collected from mothers on condition of confidentiality. These studies were used by the agency in its 2016 human health risk assessment and drinking water exposure assessments which concluded:

This assessment shows dietary and drinking water risks for the current uses of chlorpyrifos. Based on current labeled uses, the revised analysis indicates that expected residues of chlorpyrifos on food crops exceed the safety standard under the Federal Food, Drug, and Cosmetic Act (FFDCA). In addition, the majority of estimated drinking water exposure from currently registered uses, including water exposure from non-food uses, continues to exceed safe levels, even taking into account more refined drinking water exposure. This assessment also shows risks to workers who mix, load and apply chlorpyrifos pesticide products. (emphasis added)

But in the revised human health risk assessment released this week, EPA’s concludes

“Despite several years of study, the science addressing neurodevelopmental effects remains unresolved.” A deeper dive into the document will find a lengthy timeline of its attempts to retrieve the underlying data for the CCCEH studies, ultimately finding that “although EPA does not have a specific reason to believe that CCCEH have inappropriately handled the data or statistical analysis, it remains unable to verify the reported findings of the CCCEH papers. Moreover, EPA and interested stakeholders are unable to conduct alternative statistical analyses to evaluate the robustness and appropriateness of the approaches used by the investigators.”

This U-turn on the need for raw data from 2016 to present is remarkable. The scientific community knows best that extra care must be taken with sensitive data because even a simple anonymization process is inadequate to protect personal information. Further, redacting data and protecting privacy is difficult and time-consuming. It can also strip data of their value, as when completely public data is de-identified to such an extent that the information garnered becomes useless. For example, when it comes to understanding the impacts of pollution on health, you cannot redact information like age and location because it is vital to understanding the health impact of the contaminant. Despite the realities of cohort studies relying on sensitive data, EPA has pushed forward with its rule to eliminate studies on the basis of the underlying data not being publicly available. Yes, this means that our environmental and public health agency will effectively remove human health data from consideration as it examines human health risk.

Bending over backward to exclude a key study, EPA endangers generations

In the case of chlorpyrifos, EPA appears not to be satisfied even with Columbia’s offer to share its data with EPA at a secure location. By not making that effort to review the data, it shows that the agency isn’t interested in reviewing the science—it is just searching for reasons to exclude it. Ignoring this body of work funded by the agency itself means that it lacks the necessary evidence to formulate conclusions about chlorpyrifos’ direct human health impacts.

In a fact sheet on children’s health UCS released earlier this year, we conducted an analysis comparing US census data on children under five with the amount of chlorpyrifos used in the farmland portion of each US county, finding that 1,969,325 children live in agricultural communities which are likely facing an increased risk of harm to their brains and nervous systems because of the EPA’s failure to act to ban chlorpyrifos use. By ignoring vital evidence of the unique risk of chlorpyrifos exposure to children, EPA is failing to use science to protect our most precious population.

The EPA’s final restricted science rule is currently being reviewed by the Office of Management and Budget and once it clears review, we can expect more epidemiological and medical research excluded from the agency’s science and policies. We will be meeting with OMB next week to explain yet again how destructive this rule will be and how it stands to affect EPA’s future work on a suite of America’s most pressing issues—from understanding the risks associated with wildfires to mitigating the risks of COVID-19 through wastewater treatment.

We are fighting to ensure that this rule doesn’t see the light of day, and that it focuses instead on shoring up scientific integrity through common-sense reforms.  Check out our new factsheets for more information on how EPA and other agencies can improve scientific integrity—through transparency and accountability mechanisms—rather than issuing nonsensical rules that will only endanger lives.