A five-year study conducted by U.S. Geological Survey (USGS) researchers has found that pharmaceutical manufacturing facilities are a "significant source" of pharmaceuticals that enter the local environment.

From 2004 to 2009, USGS researchers tested outflow samples from two wastewater treatment plants in New York State where more than 20 percent of the water received by the plants is from pharmaceutical manufacturing facilities. The researchers found the pharmaceutical concentrations in the treated water that ends up in your faucet were 10 to 1,000 times higher than the outflows from 24 water treatment facilities around the U.S. (including one in New York State) that do not receive water from pharmaceutical manufacturing facilities.

Significant Levels of Pharmaceuticals Found in Samples

While the concentrations of pharmaceuticals varied from sample to sample, the maximum concentrations were significant, and included:

  • 3,800 parts per billion (ppb) of metaxalone, a muscle relaxant
  • 1,700 ppb of oxycodone, an opioid prescribed for pain relief
  • Greater than 400 ppb of methadone, an opioid prescribed for pain relief and drug withdrawal
  • 160 ppb of butalbital, a barbiturate
  • More than 40 ppb of phendimetrazine, a stimulant prescribed for obesity,
  • More than 40 ppb of carisoprodol, a muscle relaxant
  • 3.9 ppb diazepam, an anti-anxiety medication

It should be noted that levels in receiving streams were considerably lower due to dilution, but also that researchers detected levels of pharmaceuticals up to 20 miles downstream. Numerous studies have looked at pharmaceuticals levels in streams and aquifers across the U.S., and levels are typically below 1 ppb, so these levels are of concern.

Additional Studies Documenting Other Pharmaceuticals

While the study looked at seven pharmaceuticals, additional pharmaceuticals were also detected in the samples and ongoing studies are documenting their levels.

The study is part of a long-term effort to determine the effects of chemicals and to help develop effective water management practices.