So, last week, the GOP leadership of the House Resources Committee — in particular, Richard Pombo (R-Calif.) — released a report (PDF) claiming that mercury has not been linked to deleterious effects on human health, and that most mercury in the U.S. environment comes from natural sources.

The science overwhelmingly contradicts Pombo. Amanda touched on this in the latest Muckraker. Today, Chris Mooney delves further into the details, in this column and this follow-up on his blog. To summarize: A substantial portion of the mercury load in the U.S. environment comes from coal-fired power plants, and mercury stunts children’s neurological development. (Mooney also points to a new study (PDF) claiming that mercury-driven diminishment of child IQ costs the U.S. some $8.7 billion in lost productivity every year.) Fetuses are particularly at risk, which is why dozens of states advise pregnant mothers to avoid several kinds of fish. To claim otherwise, Pombo has to distort research by the EPA and the National Academy of Sciences and draw heavily from industry and conservative think tanks.

It’s hard to know what to say about this. It isn’t a “values” issue like, say, stem cells or family planning. The modern right has distorted science on those topics plenty, but at least in those cases they are defending deeply held religious or moral views. At least there’s some sort of principle involved, however risible the methods.

But there’s no principle here. No principle, and no legitimate scientific doubt. It’s simply an attempt by national legislators to cloud public debate on behalf of one of America’s biggest polluters (and GOP contributors) — at the expense of unborn children. I don’t really go in for the overstatement that characterizes many public environmental campaigns, but this does seem a pretty clear case of choosing money over children’s health. It isn’t the first time, but it is particularly brazen and transparent.