More than half of the scientists at the Environmental Protection Agency who responded to a survey said they had experienced political interference in their work.
The survey results show "an agency under siege from political pressures," said the Union of Concerned Scientists report, which was released Wednesday and sent to EPA Administrator Stephen L. Johnson.
The online questionnaire was sent to 5,419 EPA scientists last summer; 1,586 replied, and of those, 889 reported that they had experienced at least one type of interference within the last five years.
Such allegations are not new: During much of the Bush administration, there have been reports of the White House watering down documents on climate change, industry language inserted into EPA power-plant regulations and scientific advisory panels' conclusions about toxic chemicals going unheeded.
But Francesca Grifo, director of the scientific integrity program for the Union of Concerned Scientists, a Washington-based nonprofit group, said the survey documented the widespread nature of the problem at the EPA. "What we've been up against until now is anecdotal evidence," Grifo said.
She acknowledged that scientists who were frustrated or upset might have been more likely than those who were satisfied to respond to her organization's survey, but added: "Nearly 900 EPA scientists reported political interference in their scientific work. That's 900 too many."
EPA spokesman Jonathan Shradar noted that administrator Johnson had had a 27-year career as a scientist himself.
"We have the best and finest scientific community in the world at EPA," Shradar said. "All of the issues we deal with are issues that we all are very passionate about. It's important that we let the scientists do the science and allow policymakers to do the policy work."
The survey respondents were split over the impact of political interference on regulations. According to the report, 48% believed that the EPA's actions were "frequently or always" consistent with scientific findings, and 47% believed that agency policy "occasionally, seldom or never" made use of scientific judgments.
In optional essays, scientists repeatedly singled out the Office of Management and Budget at the White House, accusing officials there of inserting themselves into decision-making at early stages in a way that shaped the outcome of their inquiries. They also alleged that the OMB delayed rules not to its liking. EPA actions "are held hostage" until changes are made, a scientist from the EPA's Office of Air and Radiation wrote.
Some also accused members of Congress of inappropriate intervention.
All of the respondents remained anonymous.
J. William Hirzy, an EPA senior scientist and union official, said that politics trumped science at times during the Clinton administration as well but that "what we're seeing now is . . . the favoring of energy interests, coal-fired power plants. That's something different in this administration."
Rep. Henry A. Waxman (D-Beverly Hills) wrote to Johnson on Wednesday asking him to be prepared to respond to the findings at a hearing next month of the House Committee on Oversight and Government Reform.