Streams and Recycled Water Filled With Nasty Surprises

Water released from recycling plants has some alarming compounds that result from mixing chlorine with pharmaceuticals-and some of them are highly toxic.

Have you ever wondered what happens to painkillers, antibiotics, hormones, caffeine and antibacterial soap they end up in the wastewater? The National Institute of Standards and Technology (NIST) is researching what happens when they mix with chlorine. Scientists around the world are finding many drugs in their wastewater, but little is known about the byproducts of those drugs created during chlorine treatment or time spent in the environment. Among the concerns is possible damage to the environment, animals and people from bioactive compounds. NIST chemists selected four pharmaceuticals and found that the reactions are complicated and often produce unexpected products. For example, acetaminophen forms multiple products, two of which are highly toxic. All the drugs transformed significantly and their products were more hydrophobic than the parent chemicals. Hydrophobic compounds are more likely to stay in the body, but it isn't known whether these reaction products pose any health or environmental hazards. The U.S. Geological Survey did a separate study targeting 95 organic wastewater contaminants of which 82 were found in one stream. In 35 percent of the streams the scientists found 10 or more compounds with a surprisingly high prevalence of mixtures. The chemicals included cotinine, a nicotine breakdown product, caffeine, cholesterol, steroids, the insecticide DEET, flame retardant, and a detergent breakdown product with endocrine disruptive properties. For most of these chemicals, drinking water standards, human health advisories or criteria to protect aquatic life do not exist. However previous research has shown that exposure to levels reported can illicit deleterious effects in aquatic species. All the more reason for making sure that stormwater run-off and water restoration projects are handled with care and energy. For more information go to: https://toxics.usgs.gov/regional/emc.html