Trump administration appointees at the Environmental Protection Agency (EPA) meddled in agency science to weaken the toxicity assessment of a dangerous chemical, a new report by the US body’s internal watchdog has found.In response to what it labeled “political interference”, the Biden administration in February 2021 pulled the assessment, republished it months later using what it said is sound science, and declared it had resolved the issue.But EPA scientists who spoke to the Guardian say several employees willingly worked with the Trump appointees to weaken the assessment, and they were never reprimanded or fired.The scientists say the controversy is part of a deeper problem afflicting the EPA: industry influence on career staff, and an unwillingness from the EPA to address it.“The issue is part of the larger rot at the agency of career staff working with industry to weaken the EPA,” a current agency scientist familiar with the situation said. The scientist did not use their name for fear of reprisal.The controversy centered around a 2021 toxicity report for PFBS, a type of PFAS compound that is toxic at low levels. Research has linked the chemical to kidney disease, reproductive problems and thyroid damage, and it has been found throughout the environment, including in an estimated 860,000 Americans’ drinking water.PFAS are known as “forever chemicals” due to their longevity in the environment, and are a growing health hazard.In its recent report, the EPA’s office of inspector general described “unprecedented” interference by former Trump-appointed EPA chief Andrew Wheeler and other political appointees, who ordered the alteration of the PFBS toxicity value just as the assessment was about to be published in late 2020. The revised assessment went live just four days before Trump left office in 2021.The assessment would have been used by regulators to establish drinking-water quality standards and other environmental cleanup targets that companies must meet when addressing pollution. Instead of a specific target number, Wheeler ordered a range of toxicity values for PFBS, which meant companies required to clean up pollution could choose to leave higher levels of the chemical in the environment.That could have led to a “less costly, but possibly insufficient” cleanup, the inspector general wrote in its report, and the change’s critics say it put human health at risk. It is unlikely the revised assessment was used in the few weeks that it was publicly available, the inspector general wrote.The changes were “something that industry has always wanted”, former EPA scientist Betsy Southerland previously told the Guardian.The disagreement about the toxicity value centered around the uncertainty factor used in PFBS’s assessment, which was developed by career scientists in the EPA’s office of research and development (ORD). Uncertainty factors are designed to fill in gaps in data on chemicals’ effects on the human body. In PFBS’s case, studies on how the compound affects thyroid hormone levels and neural development were not available. The uncertainty factors would help account for those gaps.The inspector general noted the ORD’s development of the assessment was twice peer-reviewed, followed EPA review protocol, and the office of chemical safety and pollution prevention (OCSPP) had twice reviewed and signed off on the assessment.“There was a lot of rigor, a lot of involvement across the agency,” said Jennifer Orme-Zavaleta, then an ORD science adviser.Still, at political appointees’ behest, the OCSPP alternative uncertainty factors were inserted just days before the assessment was published. The new numbers were inserted without being fully scientifically vetted, and they lacked “technical and quality assurance review”, the inspector general wrote.The range of toxicity values was framed by political appointees as a “compromise” to resolve the alleged dispute between the OCSPP and the ORD, the inspector general said. The appointees also defended it as a “policy” decision, not an alteration of scientific data.After the Biden EPA pulled the assessment, it issued a statement declaring the process was “compromised by political interference as well as infringement of authorship”.During its review, the administration took no action against career employees who implemented the political appointees’ changes. Those employees “made the changes happily”, according to Kyla Bennett of Public Employees for Environmental Responsibility (Peer), but remained at the agency.An internal email thread from the Trump EPA’s waning days and comments in the inspector general report illuminate how career employees in the OCSPP either requested the changes or did not object to alterations.Among the career employees were Ana Lowit, Todd Stedeford and Tala Henry. Henry and Stedeford were previously accused by whistleblowers of altering scientific documents at industry’s behest to make other chemicals appear less toxic.Stedeford said he “adamantly opposed” the PFBS changes, and denied wrongdoing in previous allegations made against him by whistleblowers.The thread opened on 7 January 2021 with an email from Henry, then a deputy director in the OCSPP, sent to political appointees and career employees within the ORD and the OCSPP. She told the group the alterations are “something [Wheeler] has requested”.skip past newsletter promotionafter newsletter promotionThe only career EPA employee to oppose the order to change the assessment was Orme-Zavaleta, who in a response from the same day noted the assessment had already been reviewed twice and was considered “final”. Further changes would delay it for months because it would need to go through the review process, she told the group.In response to Orme-Zavaleta’s emails, a Trump political appointee said the assessment needed to be published in the next week because Wheeler had a media interview on PFAS and wanted to be able to “highlight” the assessment.“They were trying so hard to get it out before Trump left office,” Bennett said.On 8 January, a Trump appointee said Wheeler had allowed the review process to be “expedited”, and the altered assessment would be published before Biden took over the EPA.“Great news!” the appointee wrote.Wheeler’s decision “flew in the face of scientific integrity”, Orme-Zavaleta told the Guardian.The inspector general report suggests OCSPP career employees such as Stedeford, Henry and Lowit did not object to the changes: “We found no evidence that intimidation or coercion took place.”However, the three career staffers were in an “awkward position”, Orme-Zavelta said.“Career staff report to political leadership, and they were directed to make these changes,” she said. “It was a very tough position for them to say no, because that would have been insubordination.”Bennett said the employees should have pushed back: “Having been a whistleblower at the EPA myself, I understand it is not a fun place to be, but it’s better than just shrugging your shoulders and making the changes. They could have, and should have, fought back.”Lowit now works as a science adviser in the OCSPP and did not respond to a request for comment.Stedeford has since left the EPA to work for a law firm that represents chemical manufacturers.Henry retired amid the inspector general investigation late last year.Orme-Zavaleta said the controversy was “demoralizing” for ORD scientists, and some remain “bitter”.The inspector general report failed to address how to protect employees from political leadership pressure, she added. And with the EPA deeming the incident “political interference” instead of a larger problem, employees who spoke with the Guardian fear more of the same.“People know what happened, and they know there were no consequences, so there’s no deterrent,” said an employee familiar with the situation. “It’s only going to make people more brazen about doing this kind of thing in the future.” More