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USGS releases study of pharmaceuticals in wastewater
Contributions from pharmaceutical manufacturing facilities may be responsible for 10- to 1,000-fold increases in wastewater effluent pharmaceutical concentrations, according to a new study by the US Geological Survey. "This is the first study in the US to identify pharmaceutical manufacturing facilities as a significant source of pharmaceuticals to the environment," said Matthew Larsen, USGS associate director for water. Over the last decade, awareness and concern about pharmaceuticals in the water have grown. They are difficult to remove from the wastewater stream because medicines come in variety of chemical structures, each requiring different treatment methods. Furthermore, wastewater treatment plants receive pharmaceutical loads from many sources — hospitals, veterinary clinics, households and even pharmaceutical manufacturing facilities. These facilities are required by the US Environmental Protection Agency manufacturing effluent discharge and emission regulations to pre-treat their effluent before sending it to public utilities. In addition, the high cost of active pharmaceutical ingredients should discourage waste. Yet, the USGS study reveals that these facilities make previously underestimated contributions to the pharmaceutical load of wastewater treatment plants. The five-year study compared two New York treatment plants that receive more than 20 percent of their wastewater from pharmaceutical formulation facilities with one that receives none. USGS researchers tested wastewater outflow for commonly detected pharmaceuticals including muscle relaxers, opiod pain relievers and anti-anxiety medication. They also compared these results to a national survey of 23 treatment plants that do not receive effluent from pharmaceutical formulation facilities, although half of these plants do receive hospital wastewater. Even so, the maximum drug concentration of all 24 treatment plants lacking pharmaceutical manufacturing effluent was generally less than one ppb (1 microgram/L), which is the equivalent of one drop of water in an Olympic-sized swimming pool. However, samples from the two treatment plants receiving pharmaceutical effluent revealed a complex mix of medications. Some samples exposed pharmaceutical concentrations that were 10 times to 1,000 times higher than average. For example, researchers found concentrations of metaxalone, a muscle relaxer, at 3,800 ppb (3,800 micrograms/L) and oxycodone, an opiod pain reliever, at 1,700 ppb (1,700 micrograms/L). Research about both the human and animal health effects of low level pharmaceutical exposure is ongoing. However, higher levels of pharmaceuticals introduced by manufacturing facilities may present risks previously unaccounted for by current toxicological assessments. This study and additional information about water quality can be found online.
Kristina Twigg, Contributing Editor
Posted: 06/29/2010
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