Imagine if a government scientist discovered unseen bacteria in the air that posed serious health risks to the public, but was ordered to suppress the research by an agency with connections to the very industry producing the hazard. It sounds like something from a Michael Crichton novel or Hollywood thriller. Unfortunately, the case is real, and is becoming an all-too-familiar practice within the Bush administration.

Appointees of past Republican administrations and senior scientists who have advised administrations of both parties have concluded that the breadth and magnitude of the Bush administration’s manipulation, suppression, and misrepresentation of science is unprecedented. Russell Train, Environmental Protection Agency administrator under Presidents Nixon and Ford, said recently, “How radically we have moved away from regulation based on independent findings and professional analysis of scientific, health and economic data by the responsible agency to regulation controlled by the White House and driven primarily by political considerations.”

Indeed, more than 20 Nobel laureates have joined scores of the nation’s top scientists in charging that the Bush administration’s abuse of science reaches across a wide range of agencies and issues. For example, in a clear effort to forestall growing demands for mandatory limits on emissions of carbon dioxide and other heat-trapping gases, the administration has consistently sought to undermine the public’s understanding of how the consumption of fossil fuels contributes to global warming. Just last year, White House officials demanded so many unsupported changes to the climate change section of the EPA’s draft report on the state of the environment that the EPA scientists deleted the entire section rather than agreeing to publish it.

In response to the episode, Dr. F. Sherwood Rowland, a Nobel laureate in chemistry, said, “The public deserves rational decision-making based on the best scientific advice about what is likely to happen, not what political entities might wish to happen.”

Consider the issue of lead poisoning. In 2002, an expert advisory committee to the Centers for Disease Control and Prevention appeared ready to recommend a more stringent federal lead standard on the basis of new public health data. But just before the advisory committee was to meet, Health and Human Services Secretary Tommy Thompson took the extraordinary step of rejecting several qualified researchers nominated by the agency’s scientific staff to serve on the committee. Two of his substitute choices were handpicked by the paint industry.

Another example involves endangered species. After more than a decade of research, a team of scientists advising the government recommended changes in the flow of the Missouri River to protect some bird and fish species, changes opposed by agricultural interests and the barge industry in a key electoral state. A senior political appointee at the Department of the Interior created what he called a “SWAT team” of other agency scientists to review the earlier opinion. A retired U.S. Fish and Wildlife Service biologist who had supervised the study for more than five years told the press, “It’s hard not to think that because our findings don’t match up with what they want to hear, they are putting a new team on the job that will give them what they want.”

The list goes on and on, with manipulation of scientific knowledge and science advisory committees from mercury emissions and forests to worker safety, missile defense, and nuclear weapons. The suppression and distortion of science carries serious implications for our future. One long-term effect of the administration’s behavior could be widespread demoralization of researchers at the federal agencies, many of whom already feel their integrity is being compromised. According to Dr. Margaret Scarlett, who worked at the CDC for 15 years, “We’re seeing a clear substitution of ideology for science and it is causing many committed scientists to leave the agency.”

The Nobel laureates and senior scientists say the abuse of science must stop to protect the public’s health and safety. Congress should hold oversight hearings and guarantee public access to government scientific studies and other measures to prevent such abuses in the future. And action should be taken to reestablish an organization able to independently assess and provide guidance to Congress on technical questions bearing on public policy.

Only then will we read about these practices in best-selling thrillers rather than the pages of our newspapers.

Kevin Knobloch is president of the Union of Concerned Scientists,