Moderate to High Chemical, Drug Levels Found in Lake Michigan

We have long followed the issue of pharmaceuticals in drinking water and the danger of these drugs on human, environmental, and aquatic communities. Now, reports are emerging that prescription medications are contaminating Lake Michigan.

The findings indicate that the lake is not diluting the drugs, which is what science has long believed, according to Environmental Health News, citing the new research. If the compounds are able to travel and remain at high levels, the aquatic life are exposed and there could also be “some serious near-shore impacts,” Rebecca Klaper, an associate professor at the University of Wisconsin-Milwaukee, told Environmental Health News. Milwaukee draws its drinking water from Lake Michigan.

Researchers discovered that 14 of the chemicals “were found to be of medium or high ecological risk,” and that the concentrations “indicate a significant threat to the health of the Great Lakes,” according to Environmental Health News. “In a body of water like the Great Lakes, you’d expect dilution would kick in and decrease concentrations, and that was not the case here,” Dana Kolpin, a U.S. Geological Survey research hydrologist based in Iowa, told Environmental Health News.

Researchers tested effluent from two sewage outfalls and water and sediment from Lake Michigan for 54 chemicals commonly used pharmaceuticals and personal care products. They discovered 27 chemicals in the lake. The four most frequently found were metformin, a diabetes drug; caffeine; sulfamethoxazole, an antibiotic; and the antibacterial and antifungal, triclosan, Environmental Health News reported. “Wastewater treatment plants are simply not designed to remove these chemicals,” Klaper said. “This tells us we shouldn’t assume that dilution solves the problem of putting these into the environment.”

According to the researchers, 14 of the chemicals “were found to be of medium or high ecological risk,” and concentrations “indicate a significant threat to the health of the Great Lakes, particularly near shore organisms.” Of those, triclosan has been proven seriously toxic to algae and acts as a hormone disruptor in fish, Environmental Health News noted.

“You’re not going to see fish die-offs but subtle changes in how the fish eat and socialize that can have a big impact down the road,” said Kolpin, who was not part of the study, told Environmental Health News. “With behavior changes and endocrine disruption, reproduction and survival problems may not rear their ugly head for generations.” Kolpin pointed out that, “The problem is the effluent and water don’t have one compound but a chemical mixture soup…. It’s going to be hard to tease out which of these compounds may do harm” to people or fish.

The U.S. Environmental Protection Agency (EPA) considers pharmaceuticals in our waterways to be an “emerging concern,” saying that the chemicals may pose risks to wildlife and humans. Meanwhile, 12 pharmaceuticals are listed on the EPA’s Contaminant Candidate List, which includes chemicals that may require regulation under the Safe Drinking Water Act, according to Environmental Health News.

We previously wrote that showers and baths could also be polluting our waterways with hormones and antibiotics pointing to the release of active pharmaceutical ingredients (APIs) into our water. In fact, bathrooms are responsible for much of the APIs release into the environment, with research pointing to toilets as a main conduit of drug release into the water. API excretion via urine and feces into toilets follows a path into sewage treatment plants, which could could pass through disinfection entering lakes, rivers, and oceans. Some APIs also taint the environment when medications are intentionally and unintentionally flushed down toilets.