Jill Wisehart, director of communications for the American Water Works Association Research Foundation, says the amount of these drugs typically found in drinking-water supplies is "like one drop in a swimming pool."
Kyla Bennett, a former biologist with the federal Environmental Protection Agency, and the current New England director of Public Employees for Environmental Responsibility, counters Wisehart's analogy: "They're not looking at the chronic ingestion of small quantities of dozens or hundreds of drugs (through the drinking-water supply). We don't know what that will do to people."
The existence of drugs in at least some Tucson drinking water has been proven: During tests done in 2002, trace amounts of three pharmaceuticals were found by Tucson Water in a well located north of the Ina Road sewage-treatment plant. These three drugs were carbamazepine, which is used by people with epilepsy; dehydronifedipine, a heart-medication byproduct; and sulfamethoxazole, an antibiotic often used to treat urinary-tract infections.
These Tucson test results were included as part of a March series by The Associated Press on pharmaceuticals in drinking water. In its nationwide survey, the AP reported at least one drug was found in the water supplies of 24 out of 62 major metropolitan areas.
Even though extremely small amounts of drugs are showing up in the water supplies of at least 41 million Americans, the EPA has no standards for them. On its Web page, the agency declares, "To date, scientists have found no evidence of adverse human health effects from (pharmaceuticals and personal-care products) in the environment."
Reinforcing that opinion, in a press release issued shortly before the AP series appeared, the American Water Works Association noted: "Research throughout the world has not demonstrated an impact on human health from pharmaceuticals in drinking water at the trace levels at which they have been found."
Once the AP series started running in newspapers across the country, a press release from the Pharmaceutical Research and Manufacturers of America stated: "It is important to remember that peer-reviewed research studies conducted to date suggest it is highly unlikely that these extremely small quantities of pharmaceuticals would be harmful to human health."
On the other hand, the AP series cited an unlikely source of concern on the issue: Mary Buzby, environmental technology director for drug-giant Merck.
"There's no doubt about it," the AP quoted Buzby as saying at a 2007 conference, "pharmaceuticals are being detected in the environment, and there is genuine concern that these compounds, in the small concentrations that they're at, could be causing impacts to human health or to aquatic organisms."
PEER's Bennett agrees. She claims in a report: "Fetuses are sensitive to chemicals in the parts-per-quadrillion range." She also expresses concern about the impacts of pharmaceuticals in drinking water on children, the elderly and people with immune deficiencies.
However, in that report, Bennett says officials can take steps to cut down on three major generators of pharmaceuticals into sewer systems.
"Simple steps, such as prohibiting the construction of hospitals, nursing homes and assisted-living facilities in our aquifer-protection districts and near private drinking wells, would prevent the problem from being exacerbated," Bennett says.
In this report, Bennett saves most of her criticism for the EPA, or the "Everything's Polluted Anyway" agency of the Bush administration, as she refers to it in a telephone interview.
"It's kind of like waiting for a bomb to explode," Bennett says of the EPA's stance on the issue. "They're trying to sweep it under the rug."
At this point in time, the agency does not require any testing for pharmaceuticals in drinking water. Despite that, some Arizona water utilities are getting involved.
Suzanne Grendahl, the city of Scottsdale's water quality director, says her city tested the surface water they use several weeks ago at two different locations. At one, she reports, nothing was found, while caffeine was detected at the other.
"We'll probably test periodically," Grendahl says, adding that a treatment substance they'll be putting into the water for a different reason may also result in removing the caffeine.
At the same time, even though the AP series reported no drugs had been found in the Phoenix water supply, the state's capital city decided to test anyway. According to Kenneth Kroski, public information officer for Phoenix's Water Services Department, those inexpensive tests were done a few months ago.
"They all came up clean," Kronski says. "So there's nothing planned to continue to test since the benchmark tests came up clean."
The same is not true in Tucson. Tucson Water spokesman Mitch Basefsky reports the utility will conduct tests by the end of September at two locations for a host of pharmaceuticals, and then repeat the process every three years.
Basefsky says these tests will include the three previously found substances, along with testosterone, caffeine, ibuprofen and many others.
"There's no evidence of health impacts," Basefsky says of the trace amounts of pharmaceuticals found in Tucson's drinking water, "so our concern is more like we want to know what's there."