| This week’s investigative report by the Associated Press has brought us questions about pharmaceuticals in the waters of Montana. Has anyone looked for them? Where are they? Where do they come from? Should we be concerned? What can we do about them? This summary report addresses these basic questions. The report contains ‘hot links’ to the experts whose work we describe, so you can follow up with them if you have specific questions.
Sources
Pharmaceutical compounds are used by humans and in veterinary applications, including livestock rearing. They’re not completely broken down within people or animals, and so they can potentially be found in any waters influenced by human or animal waste. Treated and untreated human wastewaters (septic system leachate, sewer pipe leakage and wastewater treatment plant effluent) and the effluent from concentrated animal feeding operations are the chief sources.
Montana Studies
In 2003 a University of Montana team led by Bill Woessner looked for 22 common pharmaceuticals in leachate from the Frenchtown High School septic system, and in shallow wells in and near Missoula that could have been influenced by leachate from residential septic systems or by leakage from city sewer lines. Three pharmaceutical compounds were found to have entered the shallow subsurface at Frenchtown, and five compounds were found in Missoula ground water.
Kate Miller of the Montana Bureau of Mines & Geology (MBMG) and Joe Meek of the Montana Department of Environmental Quality surveyed ground water beneath the Helena Valley on two occasions in 2005. They tested 35 domestic water supplies, and found 22 compounds classified as “pharmaceuticals or personal-care products.” These included antibiotics, pain-killers, anti-inflamatory and seizure-control drugs, anti-depressants, estrogens and androgens, caffeine, plasticizers, insect repellent and an herbicide.
In fall 2007 the MBMG and the Gallatin Local Water Quality District sampled ground and surface water and streambed sediment several places in the rural parts of the Gallatin Valley. Preliminary results did not show contamination by pharmaceutical products; independent confirmatory samples have not yet been analyzed.
Steve Sando of the US Geological Survey recently collaborated with the Lewis & Clark Local Water Quality District and the Helena Wastewater Treatment Plant to test the water of Prickly Pear Creek above and below the mouth of the plant’s discharge canal. Some pharmaceutical residues were detected upstream of the discharge; many more were found downstream of the discharge.
Gary Icopini of the MBMG is leading a statewide study funded by the USDA Natural Resources Conservation Service to look for veterinary pharmaceuticals in a set of wells regularly monitored by MBMG across the state. These wells are in areas with land uses ranging from crop production to concentrated animal agriculture to rural subdivisions. Preliminary results from 2007 show pharmaceutical contamination ranging from none at all to concentrations that are known to act on animal organs and systems.
In summary, at this point we can say that:
- A number of studies have examined Montana waters for pharmaceuticals and other compounds that are biologically active at very low levels
- Contamination has been found in both surface and ground water, but it’s far from universal
- The observed contamination probably arises from both domestic wastewater and animal wastes
- The concentrations found in any specific sample are highly dependent on local conditions, especially the characteristics of the soil and aquifer, and proximity to sources
- Environmental concentrations differ greatly among compounds. Some compounds are much more mobile in the environment and more resistant to breakdown than others.
Significance for Montanans
Biologists know that living in water containing pharmaceuticals is unhealthy for fish, amphibians and reptiles. But would people suffer harm if we drank water containing these compounds every day? Unfortunately, unless the concentrations are relatively high – actual therapeutic dosages – no one can say. Pharmaceutical research using low, sub-therapeutic doses is very difficult, and little such research has been carried out. There are no drinking water standards for these compounds, and so no guidelines for safe levels in water.
Should individuals who are concerned send a sample of their water to a laboratory for testing? Perhaps, with caution. Because the concentrations of concern are extremely low – parts per trillion, sometimes less – few labs around the country are qualified to conduct these tests. The tests are complex and expensive, and the results are often ambiguous. The only laboratory in Montana that has tested for pharmaceuticals in water is the Agricultural Experiment Station Analytical Laboratory at MSU-Bozeman.
Montanans who are concerned about their drinking water can install treatment units at their kitchen taps. Activated carbon filters are good and reverse osmosis units are better at removing the compounds of concern. But - no treatment device works forever without maintenance – these units must be operated and kept up according to their specifications, or they’ll cease to be effective. Unless it’s been treated by reverse osmosis, bottled water is not necessarily free of pharmaceutical compounds.
For further information, consult these websites:
|
