Federal scientists testing for pharmaceuticals in water have been finding significantly more medicine residues in sewage downstream from public treatment facilities that handle waste from drugmakers.
Early results from two pivotal federal studies compare wastewater at treatment plants that handle sewage from drugmakers with those that do not. The studies cover just a small fraction of the 1,886 pharmaceutical manufacturing facilities counted in a 2006 US Census report.
In one study, samples taken at two treatment plants down the sewer line from drugmaking factories contained a range of pharmaceuticals — among them opiates, a barbiturate and a tranquilizer at “much higher detection frequencies and concentrations” than samples taken at other plants, a preliminary research by the US Geological Survey (USGS) showed.
One drug, the muscle relaxant metaxalone, was measured in treated sewage at concentrations hundreds of times higher than the level at which federal regulators can order a review of a drug’s environmental impact.
Based on secrecy agreements with the researchers, the treatment plants were not identified.
USGS researcher Herb Buxton, who co-chairs a White House task force on pharmaceuticals in the environment, said it’s important that federal scientists test the pharmaceutical industry’s claims that their wastewater is not a meaningful source of pharmaceuticals in water.
“It’s critical that those types of assumptions are confirmed through real testing,” Buxton said.
In another study, Environmental Protection Agency researchers tested sewage at a municipal wastewater treatment plant in Kalamazoo, Michigan, that serves a major Pfizer Inc factory.
Bruce Merchant, Kalamazoo’s public services director, provided data that showed unusually high concentrations of the antibiotic lincomycin entering the plant, a drug the factory was producing around the time samples were collected.
“There’s some product going down the drain,” Merchant said.
While nearly all the lincomycin was removed during wastewater treatment, some did survive. According to a separate study last year, lincomycin combined in minute concentrations with several other drugs that also have been detected in surface water made human cancer and kidney cells and fish liver cells proliferate.
Biologist Francesco Pomati at the University of New South Wales in Sydney, Australia, was so concerned with the findings that he and his colleagues warned that chronic exposure to the combination of drugs via drinking water could be “a potential hazard for particular human conditions, such as pregnancy or infancy.”
In earlier experiments, lincomycin acted as a mutagen, changing genetic information in bacteria, algae, microscopic aquatic animals and fish.
Pfizer spokesman Rick Chambers said that while the company does not test wastewater from the facility for the drugs made on site, “compliance with all environmental, health and safety laws is imperative to our business operations worldwide.”
The two domestic studies follow a burst of recent research in Asia and Europe that has started to link factories to the presence in water of drugs, including the antibiotic sulfamethoxazole, the pain reliever diclofenac and the anticonvulsant carbamazepine, as well as an antihistamine, female sex hormones and aspirin.
Researchers in India, where multinational companies have increasingly turned for the manufacture of raw pharmaceutical ingredients, found that 100 pounds (220kg) a day of the antibiotic ciprofloxacin enters a river from a wastewater treatment plant that processes sewage from dozens of pharmaceutical makers.