Sara Goodman and Hallie Martin, E&E Daily reporters

More research is needed into the potential adverse health effects of chemicals and pharmaceuticals in drinking water in order to understand which ones pose the greatest threat, a panel of experts told a House Transportation and Infrastructure subcommittee yesterday.

An Associated Press investigation in March revealed that a vast array of pharmaceuticals, including antibiotics, anti-convulsants, mood stabilizers and sex hormones, are present in the drinking water supplies of at least 41 million people in the United States (Greenwire, March 10).

While that study brought the issue to the forefront of most Americans, the U.S. Geological Survey has been documenting the presence of pharmaceuticals and other chemicals in U.S. waters for several years, according to Matthew Larsen, USGS's associate director for water. Research into what this means for human health is still very limited, he said, so it is important to gather information to determine what the potential adverse effects are.

Part of the knowledge gap comes from the fact that many of the emerging contaminants that enter the waste stream are a new focus for research because they are used in relatively small quantities -- measured in quantities of parts per billion or trillion, far below the levels of a medical dose -- and so not expected to be a significant environmental concern, Larsen said.

In addition, he cautioned that just their presence does not necessarily mean they are a threat. "Although detection is an important component of the environmental assessment, ecological and human health assessments of the levels and mixtures observed in the environment are also essential," Larsen said.

This absence of research is something that needs to be addressed, said Benjamin Grumbles, U.S. EPA's assistant administrator for water. "There's a lot to learn," Grumbles said. "We need to close the gap from what we know or don't know."

Grumbles said the most important way to close the gap is to raise community awareness by launching public awareness campaigns to educate people not to flush unused medications. "There is no doubt from EPA's standpoint that pollution prevention is the key," Grumbles said. "It's the low-hanging fruit. The toilet should not be used as a trash can."

Part of the challenge in dealing with emerging contaminants, which come from everyday products including detergents, fragrances, fire retardants, plastics and insect repellents, is that because there are so many of them, there is no one technology that can remove all of the contaminants from the water, said Keith Linn, representing the National Association of Clean Water Agencies.

"You can't install a single technology and remove all of this," Linn said. "And it's unlikely to exist in the future."
Linn was optimistic about the effects on human health, saying someone would have to drink as much water as two Olympic-size swimming pools of untreated water from Cleveland's Cuyahoga River daily to ingest as much as a single therapeutic dose of an antibiotic detected in the river.

But other experts warn that some of the chemicals are seriously impacting aquatic life. For example, a 1996 British study found that male fish living near sewage treatment plants were developing female characteristics, according to Peter deFur, a professor at the Center for Environmental Studies at Virginia Commonwealth University.

The intersex fish are particularly troubling because endocrine disruption can occur as a result of very low levels of hormonally active chemicals, Larsen said. Furthermore, a wide range of chemicals can contribute, including certain pharmaceuticals, pesticides, detergents, metals and other industrial chemicals.

Their persistence in the environment and observed effects on aquatic life at low levels emphasize the need for research into the effects from long-term exposure to the various emerging contaminants at the low levels in which they are found, panel members said.

"It's important to be careful and responsible, but it's also important not to brush this off," Grumbles said. "The problem is when you have intersex fish -- that's not acceptable."