The phrases “sound science” and “junk science” should be treated like warning signs in traffic: up ahead lies that confusing intersection of Politics and Truth. The merchants of spin will try to get you to veer left or right depending upon who is paying the bills.

The manipulation of science for politics and profit isn’t new, but it’s become increasingly disturbing.

A recent Spokesman-Review article notes that a $27 million study ostensibly launched to detect the effects of radiation releases from Hanford Nuclear Reservation had a dual purpose. It was also designed to help the government defend itself against lawsuits filed by people who say their health was harmed by radioactive fallout. Moreover, some of the people who worked on the study were employed by Hanford contractors, some of whom also face lawsuits.

The conflicts of interest deal a huge blow to the credibility of the taxpayer-funded Hanford Environmental Dose Reconstruction study. The HEDR study was also integral to a controversial finding that there was no link between Hanford radiation releases and thyroid cancers. The National Academy of Sciences has criticized the thyroid study, which doesn’t square with similar studies conducted in the Marshall Islands and the Ukraine.

The implications of such studies are enormous. That’s why they should be free of conflict and inoculated from outside pressures.

A recent survey conducted by the Union of Concerned Scientists showed that large numbers of scientists in the U.S. Fish and Wildlife Service have been directed to alter findings. It’s one thing for political leaders to ignore inconvenient data produced by their agencies, but it’s quite another to alter conclusions and then pronounce that decisions were made on the basis of “sound science.”

That undermines the credibility of all government agencies and turns matters of science into public-relations wars.

Sally Stafford, a retired biologist who worked at Fish and Wildlife for 20 years, told the Los Angeles Times that she wasn’t surprised by the survey: “Political pressures influence the outcome of almost all the cases. As a scientist, I would probably say you can’t really trust the science coming out of the agency.”

Major policy decisions depend upon the objective work of government scientists. Should we expand stem-cell research? What drugs should be approved? What chemicals can harm us? What species are in need of protection? What military weapons are worthy of pursuit?

Ideologues and profit-seekers who manipulate the work behind such important questions are putting the nation on a dangerous road.

“Sound science” needs to be more than a sound bite.