NASHVILLE, Tenn. (AP) - Two ex-U.S. Environmental Protection Agency administrators say officials should withdraw a proposed trucking emissions exemption, saying it's based on flawed scientific analysis.

Carol M. Browner under President Bill Clinton and Christine Todd Whitman under President George W. Bush criticized the glider kit trucks proposal in Friday's letter to EPA Administrator Scott Pruitt.

The letter says the industry evades diesel truck pollution standards with rebuilt, high-polluting engines in new truck bodies.

It says the EPA used a Tennessee Technological University study that the school's president has since said to avoid while potential research misconduct is investigated.

Rep. Diane Black pushed the exemption using the study funded by a Tennessee glider kit company whose employees and family donated heavily to her gubernatorial campaign.

Her campaign responded she fights for rural manufacturing jobs.

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