U.S. Water News Online
ALBUQUERQUE -- Residue from prescription drugs have turned up in two rivers in New Mexico, and scientists expect to find more as they test water from other locations.
Estrogen-type drugs were found in the San Juan River in northwestern New Mexico. Residues of painkillers and seizure medicine were found in treated wastewater flowing into the Rio Grande near Espanola.
Only a few samples have been tested so far. No drug residues have been found in drinking water and officials say there is no solid evidence of human health risks.
The first results from a statewide study of drug residue in water were released by the New Mexico Environment and Health departments.
``We know they're probably coming out of the pipe at every sewage treatment plant,'' said Dennis McQuillan of the New Mexico Environment Department.
But he and David Mills, director of the Scientific Laboratory Division of the Health Department, said more study is needed before the scope of the problem is known.
``I don't want to be too alarmist at this point,'' Mills said. ``At this point, it's a research project.''
The drug residues could be getting into rivers several ways. People who take prescription medicine don't absorb all of it, so some is excreted and ends up in the sewage system. Unused medicines also can be flushed down the toilet.
Drugs excreted by livestock and then washed into rivers by runoff are another potential source, officials said.
Conventional sewage treatment technologies do not completely remove the drug residues. Other methods, such as activated carbon filtration or treatment with ultraviolet light, likely would remove the drugs but could be costly, said Bill Turner, New Mexico's natural resources trustee.
Drug residues could contaminate drinking water wells if the wells are near a river, he added.
The painkiller Darvon and anti-seizure medication Dilantin were found in very low levels, varying from 250 to 500 nanograms per liter of water, in the effluent from the Espanola waste-water treatment plant.
A nanogram in a liter of water is roughly equivalent to one second out of 32 years, Bouwer said.
Despite the low levels, health experts are concerned about the potential risks, said John Meyer, head of the chemistry bureau at the New Mexico Health Department's lab in Albuquerque.
Meyer said the department is in the early stages of testing and couldn't talk more about specifics.
The drug residues can affect wildlife. The estrogen drugs in San Juan River were found at levels high enough to cause sexual disruption in fish, officials said.
While the effects on aquatic life have been documented, there has been little more than theorizing about the dangers to humans from drug residue in water.
The New Mexico Health Department is worried about the potential for antibiotics to get into water sources and create antibiotic-resistant bacteria. A resistant strain of salmonella was found in the Rio Grande in southern New Mexico within the past few years, McQuillan said.
Turner said evidence of caffeine, codeine, cholesterol-lowering agents, anti-depressants and other drugs in water supplies in other places has him worried.
As Albuquerque and Santa Fe plan to start diverting water from the Rio Grande for drinking, Turner said it is time to seriously study the issue.
``I don't know what the ultimate solution is,'' he said. ``But I think the dialogue needs to start.''
The state laboratory is testing for 28 types of pharmaceuticals. Next year, Mills said he hopes to enhance its technology to enable tests for antibiotics and other drugs.
Tests of private wells downstream from the Santa Fe sewage treatment plant and of the Rio Grande at Pilar and Bernalillo turned up no drugs.
The U.S. Geological Survey is testing water samples from several states, including samples from Kirtland Air Force Base and White Sands Missile Range, as part of a national program to assess contamination from prescription drugs.
New Mexico will continue to collect and test treated sewage effluent, river water, groundwater and drinking water. McQuillan said once the state lab works through a backlog of samples, new samples will be collected from five sites in the middle Rio Grande.
Return to the U.S. Water News Archives page Or Return to the U.S. Water News Homepage
Editor@uswaternews.com
*Your Name:
*Your Email:
*Friend's Email:
Use a comma to separate e-mail addresses:
*Your Comments:
Hi, I thought you might like to read this article.
*Required Fields