Pharma's potential impact on water quality

Wastewater from homes and pharmaceutical manufacturing sites typically goes to treatment plants. Some of the compounds in the water might be biologically active, toxic or persistent, but treatment plants cannot always remove all of the substances before the treated water is discharged into streams or rivers. Little is known about the extent of water contamination from the pharmaceutical industry, in part because companies usually do not disclose details about their manufacturing activities or the identities of the compounds they use. Heinz Singer and colleagues from the Swiss Federal Institute of Aquatic Science and Technology (known as Eawag) wanted to compare compounds in discharged wastewater from two treatment plants near the Rhine River in Switzerland: one that receives only domestic wastewater (WWTP_dom) from homes and small businesses, and one that also receives wastewater from a pharmaceutical manufacturing site (WWTP_ind).

For three months, the team collected daily samples of treated wastewater from the plants and analyzed the substances in them using high-resolution mass spectrometry. Because the pharmaceutical industry typically produces single batches of drugs separated by time, the researchers looked for compounds that showed large variations. They found more of these highly variable compounds in water from WWTP_ind than from WWTP_dom. The team identified 25 compounds as pharmaceutical industry-related substances, including antidepressants and opioids, and their peak levels were much higher in the water from WWTP_ind than from the plant that only handled domestic wastewater. The researchers also detected several of these substances more than 60 miles downstream in the Rhine River, and their levels correlated with those at WWTP_ind. These findings indicate that a single company can impact the drinking water resource for millions of people, the researchers say.