Municipal water supplies around the country — including ours — contain trace elements of discarded pharmaceuticals. Should you be worried?



Across the United States, scientists are detecting low concentrations of pharmaceuticals in lakes, streams, drinking water and soils irrigated with reclaimed water. More than 80 percent of waterways tested in America show some traces of common medicines such as acetaminophen, hormones, blood pressure medications, codeine and antibiotics, according to the United States Geological Survey (USGS).

In early 2008, the Associated Press released a report detailing its investigation of pharmaceuticals found in the drinking water of 50 American cities. Philadelphia ranked highest on that list, with 56 pharmaceuticals and pharmaceutical byproducts in its treated drinking water — including azithromycin, tetracycline, amoxicillin and prednisone. Trace amounts of only three pharmaceuticals were found in New Orleans tap water: the hormone estrogen, the cholesterol-lowering drug clofibrate and the anti-inflammatory naproxen.

While consumer watchdogs and scientists agree that New Orleans drinking water is safe, some hold that any amount of dope in the water is too much. "It's really disconcerting to learn [how many pharmaceuticals] have been found in our waters," says Charlotte Smith, a pharmacist as well as founder and president of PharmEcology Associates, a Wisconsin-based company dedicated to managing pharmaceutical waste.

Karen Irion, administrator of the Safe Drinking Water Program for Louisiana's Department of Environmental Quality (LDEQ), says the state does not test drinking water for pharmaceuticals because the Environmental Protection Agency (EPA) does not require it to do so.

"We're living in the toilet of the nation," Irion says. "We already know the water is contaminated when it gets down here, so we take care of it through to the molecular level."

The source of New Orleans drinking water is, of course, the Mississippi River. Everything between the Rocky Mountains and the Appalachians drains primarily into the Mississippi — including treated sewage water from two-thirds of the United States. That suggests that most concentrations of drugs found within the river's watershed region eventually will flow through New Orleans, but not necessarily through your home tap.

Pharmaceuticals enter the sewer system when humans excrete unmetabolized medicines or put medication down the drain. Wastewater treatment plants, however, are not designed to remove medicine from sewer water. When treated water is released from wastewater plants into streams, rivers and other water bodies, the remnants of highly engineered chemical compounds enter the environment. They can also enter through agricultural runoff, via animal excrement and manure-based fertilizer. In New Orleans, pharmaceuticals may also find their way into the environment through soft, sinking soils and broken sewer lines, a problem associated with a pipe system more than a century old.

Scientists are uncertain about the potential health risks pharmaceuticals — as well as medications that mix with other pharmaceuticals, chemicals and pathogens — may have on humans, aquatic life and the environment. One thing they do know, however, is that "a release into the environment of antibiotics in low levels can contribute to antibiotic resistance," says Herbert Buxton, coordinator of the USGS Toxic Substances Hydrology Program. "Even soil microbes get exposed at low levels, and they may start to develop an antibiotic resistance."

Buxton points out that in addition to humans, livestock — which are often treated with preventative medicines — can contribute to the problems.

"If an animal is sick and the pathogen escapes [into the environment] — whether the pathogens are exposed to the antibiotic in the animal or in the environment — it may either develop to maintain an antibiotic resistance or to develop a [new] antibiotic resistance," he says.

All New Orleans tap water is filtered and chlorinated. It goes through tertiary treatments including oxidation, in which oxygen is shot into water to create a mini-explosion that destroys or breaks down chains of bacteria and chemicals so they can be treated at the molecular level. Irion says the process should break up pharmaceuticals as well. She is in charge of enforcing drinking water rules for the whole state, following guidelines set by a federal, EPA-provided list. Pharmaceuticals are not on that list; instead, the LDEQ looks for the EPA's chosen 100 chemicals and bacteriological constituents. The department also reviews the occurrence of the EPA's "unregulated contaminates" in the environment, in order to determine whether or not additional contaminants need to be regulated.

Researchers have tested New Orleans water for clofibrate and estrogen. Clofibrate is not carcinogenic to humans, but is reported to form tumors in laboratory rats. Its potential impact on the environment is in question. Dr. Glen Boyd, who directed research on pharmaceuticals in New Orleans drinking water through Tulane University prior to 2004, and others say artificial or natural estrogens that get into the biological system may interfere with normal function of the endocrine system.

The USGS has published more than 150 papers on the subject of emerging contaminants in the environment. Protection agencies, including the USGS and the EPA, red-flagged pharmaceuticals for further study when their European colleagues began discovering the chemicals in large bodies of water.

Research scientist Dr. Shane Snyder has been studying pharmaceuticals in the water and sediment for more than 15 years. At a U.S. Senate subcommittee hearing on water quality in April, Snyder provided a statement saying concentrations of pharmaceuticals being found in American drinking waters are "unfathomably low."

Elements that have supposedly been detected in drinking water in New Orleans and elsewhere were approximately 5 billion times lower than the therapeutic dose. The concentration would be the equivalent to a half-inch in the distance between the earth and the moon. In his statement, Snyder assured the subcommittee that a person could safely consume 50,000 8-ounce glasses of water per day without ill effects from the minuscule amounts of pharmaceuticals in the water.

Boyd's group tested for the same three pharmaceuticals the AP reported were found in New Orleans. His peer-reviewed, published reports demonstrated that while some of the pharmaceuticals for which his group tested were detected in local bayous and lakes, they were unable to survive the rigorous treatment applied to local drinking water. But while Snyder and Boyd both argue that pharmaceuticals in the drinking water do not pose a public health threat, they both stress the need for researchers and law enforcement agents to keep an eye on the matter.

It's likely pharmaceuticals have been in our water supply at trace levels for several decades. What has changed is researchers' ability to track and monitor their presence — and our awareness of environmental issues.

Irion says she has great confidence in New Orleans drinking water because the state's water treatment techniques are top-notch: "The thing that people die from is bacterial contamination," she says "They just had an outbreak in Colorado, because they weren't putting chlorine in their water. New York City doesn't treat their water at all. We're very, very careful here doing a lot of testing in the water." Like Snyder and Boyd, Irion believes pharmaceuticals found in the water nationwide are infinitesimal and are not a threat to human health. "We're looking at parts per quatrillion, such tiny amounts," she says. "We're far more concerned with their effect in the environment, on environmental indicators [such as] insects and frogs."

The EPA currently has no policy to prohibit dumping waste pharmaceuticals in the water, a common practice in homes and among health care professionals.

Howard Fielding manages the Drinking Water Protection Program (DWPP) for the LDEQ. "This is the first year we've talked about pharmaceuticals," he says. The DWPP is a community outreach program that works parish by parish with businesses and the public to keep unwanted elements out of source waters, including aquifers, reservoirs and lakes.

"The big thing is getting the public to know not to dispose of this stuff down the drain," Fielding says. The DWPP recommends people get rid of medicines they no longer can take by throwing them in the trash, unless the manufacturer or health officials tell them otherwise.

Fielding says the group has not approached health care facilities regarding the matter, but Tony Laurent, director of pharmacy at Tulane Medical Center, says he thinks incineration, rather than drain disposal, is standard practice — but not official policy — at local hospitals. PharmEcology's Smith suggests the increased cost for health care facilities to treat pharmaceuticals as hazardous waste, rather than pouring them down the drain, outweighs environmental risks.

The "trace amounts" currently detected in drinking water may or may not have a cumulative effect on humans. "We do know there's quite a bit of pharmaceuticals in [lakes, rivers and aquifers]," Irion says. She recommendations preventive medicine for the environment: Rather than flushing unused medications, "Mix them with coffee grounds or something that will destroy them and throw them in the trash," she says. "What you flush gets into the environment, the food chain or in the drinking water."


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