Tue, Mar 11, 2008 (2:07 a.m.)

A five-month analysis has shown that a wide variety of pharmaceuticals has been found in the water supplies of millions of Americans.

The analysis, done by the Associated Press, also suggests that rather than this being a problem confined to the 24 metropolitan areas studied, pharmaceutical contamination could exist at some level in all U.S. water systems.

The Las Vegas Valley’s water system tested positive for carbamazepine and phenytoin, both anti-seizure medications, and meprobamate, used to treat anxiety disorders, AP reports.

Pharmaceuticals were present in trace amounts far below the levels of a typical dose, AP reports. They included ibuprofen and other over-the-counter medicines in addition to prescription medications such as antibiotics, mood stabilizers and sex hormones.

Although the water systems tested by AP met all current water quality standards, the federal government doesn’t require testing or set limits for pharmaceuticals. Some municipalities test for a few drugs, according to AP, but most wastewater filtration systems are not designed to remove all drug residue.

Laboratory research has shown that even small amounts of some medications can adversely affect certain human cells. And other research has shown that pharmaceuticals have adversely altered some species of fish and other wildlife by contaminating natural water supplies.

But such research has been highly limited and leaves far too much in question, scientists say. Shane Snyder, research and development project manager for the Southern Nevada Water Authority, told AP that the Environmental Protection Agency must “make a statement about the need to study effects, both human and environmental.”

No doubt.

Although AP’s study showed pharmaceuticals in only trace amounts, it is obvious that the presence of these substances could increase as populations and the amounts of drugs they use increase. Meanwhile, the globe’s water supply doesn’t get larger. It remains the same.

EPA officials told AP they are taking the problem “very seriously.” But we’d like to see more evidence of that through a concerted effort to fully study how pharmaceutical contamination affects humans and wildlife and to develop technology to better screen these substances out of our water systems.