Then-presidential candidate Donald Trump shakes hands at a campaign appearance at Fitzgerald Peterbilt in Glade Spring, Va., in August 2016. The company is affiliated with Fitzgerald Glider Kits, which has pushed the Trump administration to repeal tighter emission standards for some freight trucks. (Evan Vucci/AP)

When the Environmental Protection Agency this week proposed repealing tighter emissions standards for a type of freight trucks, it cited research conducted by Tennessee Tech University but underwritten by the biggest truck manufacturer challenging the rule.

Fitzgerald Glider Kits — which makes new truck bodies, called gliders, that house refurbished engines — had questioned both the legality and data underpinning the Obama-era rule. Its products would have been required to meet the tougher pollution standards starting in January.

The company's recent petition to the EPA included a letter signed by Tennessee Tech's president and the head of the school's Center for Intelligent Mobility, soon to be housed in a new facility built by Fitzgerald. EPA Administrator Scott Pruitt, who two months earlier had met with company officials, quickly agreed their arguments had merit.

It was the latest example of a profound shift unfolding in the EPA under President Trump, in which the agency has reassessed its own data and analyses at the prompting of corporations. On pesticides, chemical solvents and air pollutants, Pruitt and his deputies are using industry figures to challenge past findings and recommendations of the agency's own scientists.

Such change has drawn praise from longtime EPA critics, such as House Science Committee Chairman Lamar Smith (R-Tex.).

"Throughout the Obama administration, Science Committee hearings repeatedly revealed faulty, one-sided science as the underpinnings of EPA regulations. Administrator Pruitt has taken a different approach," Smith said in a statement. "His actions make clear that he is working to unburden American families and to ensure this administration's policies are based on sound, transparent science."

But environmentalists contend Pruitt is sidelining agency scientists on key decisions.

"What stands out in this administration is the overt way in which career staff, especially scientists, are viewed as unfriendly or on the other side," said Ken Cook, president of the nonprofit Environmental Working Group. "He's just stiff-arming the entire scientific process."

During his confirmation hearing before Congress in January, Pruitt testified at length about the need for credible science to guide the EPA's decision-making. "If confirmed, it will be my privilege to work with EPA scientists," he wrote in response to questions from Sen. Cory Booker (D-N.J.). Independent peer review "is critical to ensuring the integrity of scientific research," and "sound, objective science must serve as 'the backbone' of EPA actions."

Detractors say his actions tell a different story.

Pruitt has questioned the legitimacy of the agency's work on climate science, and continued pressing for the White House to create a "red team-blue team" effort to debate the expert consensus on climate change. One idea would be to publicly scrutinize a massive new federal climate report, complied by scientists at 13 different agencies, affirming that human activity is driving recent global warming and could produce dire consequences in the coming decades.

Last month, Pruitt moved to change the makeup of EPA advisory boards — including panels that help prioritize the agency's research and provide recommendations on federal air-pollution and chemical exposure limits — reflecting his broader effort to shift the way the agency evaluates science. He cut any researchers currently receiving EPA grants from the committees, on the grounds that this funding poses a conflict of interest, while bringing in advisers whose work is funded by industry.

Several new appointees have blasted the EPA in the past for the science it used to justify tougher limits on pollutants and chemicals. The new chairman of the Clean Air Scientific Advisory Committee, consultant Louis Anthony "Tony" Cox Jr., argued in 2015 the agency had erred in concluding that stricter smog limits would protect public health.

"What we're trying to do is ensure that the process and that the methodology we're using is something folks have confidence in, and I think that this is a step toward that," he told reporters.

Pruitt's public schedule shows dozens of meetings with industry trade group officials and top executives from chemical, agricultural and fossil fuel companies — yet only holds periodic meetings with his own staff members about policy issues.

"EPA reviews all comments, research and data submitted to the agency, as part of understanding the issue, so that the agency can make informed decisions," spokeswoman Liz Bowman said.

Yet the question of which studies should guide the EPA's decision-making has cropped up repeatedly since the former Oklahoma attorney general came to Washington.

One of the most polarizing cases emerged in March, when he put the brakes on banning the pesticide chlorpyrifos, which has been used by farmers for a half-century to kill pests on a range of crops.

The EPA prohibited its spraying indoors to combat household bugs more than a decade ago. But in 2015, the agency proposed revoking all uses of chlorpyrifos on food in response to a petition filed by the Natural Resources Defense Council and Pesticide Action Network North America. The two groups cited scientific evidence about the potential health risks to fetal neurological development.

In March, facing a deadline to decide on the petition, Pruitt changed gears and withdrew the proposed ban. He said he wanted to provide "regulatory certainty to the thousands of American farms that rely on chlorpyrifos" and that reversing the previous administration's decision amounted to "returning to using sound science . . . rather than predetermined results."

The scientific arguments Pruitt chose to rely on came in part from the chemical industry itself. Dow AgroSciences, which manufactures chlorpyrifos, questioned epidemiological studies using data from human subjects rather than lab animals and said the EPA's assessment of the chemical's safety "lacks scientific rigor." The Agriculture Department also raised concerns about the EPA's methodology, and Pruitt cited those divergent views in his decision.

The EPA might not formally revisit questions about the safety of chlorpyrifos until 2022, when the agency is mandated to reevaluate the pesticide.

Other industry groups are now pushing for review of the EPA's scientific assessment of chloroprene, a chemical the agency identified as a likely carcinogen in 2010.

Smith and the chair of his panel's environment subcommittee, Rep. Andy Biggs (R-Ariz.), wrote Pruitt on Oct. 12 asking for a briefing and documents related to the analysis underpinning the assessment. They questioned why the EPA "ignored the conclusion of the highest quality study" cited by a consultant for Denka Performance Elastomer, the Japanese company that operates the sole U.S. chloroprene manufacturing plant.

That consultant, Kenneth Mundt, said Friday that he and several other researchers believe the EPA erroneously calculated the high cancer-risk levels it attributed to chloroprene. The research he had referenced, which did not find an elevated risk, was funded in part by U.S. and French chloroprene manufacturers.

Mundt, Denka officials and some of the firm's other consultants met on Oct. 30 with seven EPA officials to discuss the science surrounding chloroprene.

"In the past, it was difficult to get our perspectives considered at EPA . . . if you had some relationship with industry, because the door would be closed," he said. "But that's easing, and there's an increasing sense of cooperation, at least on the part of the scientists."

Pruitt is now giving the EPA data behind the 2016 truck emissions rule another look, as the agency moves forward with its repeal. The aim of the rule was to apply the stricter pollution controls that already existed for other types of trucks to gliders.

EPA modeling, which assumed that most gliders use pre-2002 engines, found that they emit anywhere from 20 to 40 times as much nitrogen oxides and soot as trucks with new engines. But the petition filed by Fitzgerald cited Tennessee Tech testing that concluded gliders "performed equally as well and in some instances out-performed" vehicles with newer engines. The document, which the company submitted with Harrison Truck Centers and Indiana Phoenix, did not include specific results from those tests.

Tennessee Tech spokesman Dewayne Wright said via email that one of the school's engineering professors went with graduate students "to a Fitzgerald facility to conduct independent research" on the EPA rule. The discussion of housing the school's Center for Intelligent Mobility in the Fitzgerald Technology Complex took place after the first tests were completed, he added.

"Tennessee Tech continually looks for ways to expose students to real-world situations and problem solving, and this was an excellent opportunity for our students, under the guidance of a Tech faculty member, to conduct such research," Wright said.

EPA staff members are doing their own round of emissions testing on a glider kit in an agency lab. But Pruitt has already proposed the rule rescinding the Obama-era standards that Fitzgerald wants gone — before the tests are finished.

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