WASHINGTON — 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-Texas.

“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.