Most U.S. Drinking Water Contains Small Amounts of Medications, Investigation Finds

The drinking water for at least 41 million U.S. residents contains small amounts of a "vast array of pharmaceuticals," according to a five-month investigation of the 50 largest U.S. cities conducted by the Associated Press, the AP/San Francisco Chronicle reports.

Water providers claim that the amounts -- which register at levels of parts per billion or trillion, "far below the levels of a medical dose" -- are safe for human consumption. However, scientists have raised concerns about the long-term effects that exposure to small amounts of antibiotics, anti-convulsants, mood stabilizers, sex hormones and over-the-counter medications in drinking water might have on human health. The federal government has not established limits on the amounts of medications in drinking water and does not require tests to determine the amounts present.

For the investigation, the AP reviewed hundreds of scientific reports; analyzed federal drinking water databases; visited environmental study sites and treatment facilities; interviewed more than 230 officials, academics and scientists; and surveyed the 50 cities and a dozen other major water providers, as well as smaller community water providers in all 50 states (Donn et al., AP/San Francisco Chronicle, 3/10).

The investigation found medications present in drinking water for 24 of 28 cities that had their water tested (Leonnig, Washington Post, 3/10). In addition, the investigation found the presence of medications in a number of watersheds, the natural sources of most drinking water. The investigation found medications present in watersheds for 28 of 35 cities that had them tested (AP/San Francisco Chronicle, 3/10).

Causes, Implications
According to the AP/Chronicle, an increased amount of unmetabolized or unused medications is "flushed down the toilet," and, although "wastewater is treated before it is discharged" into water supplies, "most treatments do not remove all drug residue" (AP/San Francisco Chronicle, 3/10).

No "clear evidence of a human health threat from such low levels of pharmaceuticals" exists, but "scientists warn that, because there has been very little study of the long-term or synergistic effects of this kind of drug exposure, water providers and regulators need to exercise caution," the Washington Post reports (Washington Post, 3/10). Recent studies have found that exposure to small amounts of medications can limit human embryonic kidney cell growth, cause inflammation in human blood cells and accelerate human breast cancer cell growth (AP/San Francisco Chronicle, 3/10).

Reaction
Benjamin Grumbles, assistant administrator for water at the Environmental Protection Agency, said, "We recognize it is a growing concern and we're taking it very seriously."

Brunel University zoologist John Sumpter said, "These are chemicals that are designed to have very specific effects at very low concentrations. That's what pharmaceuticals do. So when they get out to the environment, it should not be a shock to people that they have effects." Shane Snyder, research and development project manager at the Southern Nevada Water Authority, said, "I think it's a shame that so much money is going into monitoring to figure out if these things are out there, and so little is being spent on human health," adding, "They need to just accept that these things are everywhere -- every chemical and pharmaceutical could be there. It's time for the EPA to step up to the plate and make a statement about the need to study effects, both human and environmental."

However, microbiologist Thomas White -- a consultant for the Pharmaceutical Research and Manufacturers of America -- said, "Based on what we now know, I would say we find there's little or no risk from pharmaceuticals in the environment to human health" (AP/San Francisco Chronicle, 3/10).