Someone intends for your next glass of water to be peppered with arsenic, and it will not be the prosaic English butler with the devilish glint in his eye. Rather, at the center of this mystery is the president of the United States.

Last week, in a remarkably irresponsible move, the Environmental Protection Agency (EPA) announced the reversal of a standard proposed at the end of President Bill Clinton’s term that would have reduced the amount of arsenic permitted in drinking water by 80 percent. The current limit, which was set in 1942, has been widely judged as inadequate to keep America’s drinking water safe. However, to the jubilation of the mining industry and other arsenic producers, the Bush administration is holding to the old standard, claiming that it will eventually be lowered but only after more scientific study of the health risks it poses.

Bush’s professions that he is unconvinced by the evidence are themselves entirely unconvincing. A favorite poison of mystery writers and the Medici, arsenic is also a known carcinogen. According to one study completed in 1999 by the National Research Council, an arm of the National Academy of Sciences, the current maximum arsenic level allowed by law results in a 1-in-1,000 risk to men of developing lung or bladder cancer. Though no recent studies have been conducted on Americans, the evidence from international reports is compelling, and the researchers urged the EPA to reduce the allowable arsenic level “as soon as possible.” The current level of exposure will cause irreparable harm to Americans, and the reduction suggested by the EPA under Clinton was well advised.

The real motivation behind President George W. Bush’s reversal of the policy seems to stem not from his concern for empirical evidence, but from his loyalty to the mining industry. If forced to reduce the amount of arsenic pollution it produces, the industry would stand to lose millions of dollars; it lobbied hard to get the policy overturned and has succeeded in temporarily preserving the antiquated standards. But delay on this issue is unacceptable: every day that Bush prioritizes the mining industry’s bottom line over the nation’s welfare, more Americans will be exposed to carcinogenic drinking water.

The fact that Bush transparently panders to special interest groups is not news. What is particularly noteworthy (and insulting) about his reasoning is his purposeful rejection of scientific evidence. Covering his ears and hoping it’s not true—also known as the Bush administration plan to fight global warming—won’t help matters.

Unless, that is, Bush is willing to convince us by being the first to try a glass of water.