Emerging Concern Among “Every Day Chemicals”

A technician collects a water sample from a stream at Indiana Dunes National Lakeshore. NPS photo

You may have heard the saying “all drains lead to the lake,” but it can be hard to remember that includes what is sent down sinks, toilets, and washing machines. Many things we do in the course of a day can contribute to the contamination of surface waters (lakes and streams) in ways we cannot see. Some of these “every day chemicals” are known as contaminants of emerging concern.

In 2013, the Great Lakes Network joined six other Inventory and Monitoring Networks and the U.S. Environmental Protection Agency (USEPA) in a study analyzing samples from park surface waters for wastewater indicators, pharmaceuticals, personal care products, and pesticides. From 2013 through 2015 we collected surface water samples from four parks—Apostle Islands National Lakeshore, Indiana Dunes National Lakeshore, Isle Royale National Park, and Mississippi National River and Recreation Area. Samples from Isle Royale were not analyzed for wastewater indicators.

Estrogen, medications, DEET, and more

More chemicals and higher concentrations were detected at the two urban parks (Mississippi River and Indiana Dunes) than at the two more remote parks (Apostle Islands and Isle Royale). Fourteen wastewater indicators were detected across the three parks analyzed, including two forms of estrogen (Table 1), both of which were detected in the same sample at concentrations >100 ng/L. Concentrations of >5 ng/L are known to affect the reproduction of at least one species of minnow.

At Indiana Dunes and Mississippi River, pain relievers, anticonvulsants, antidepressants, and diuretics were the most frequently detected pharmaceuticals (Table 2). Gabapentin, an anticonvulsant, had the highest concentration of all detected pharmaceuticals.

Bisphenol A, an industrial chemical used primarily to make polycarbonate plastic and epoxy resins, and organophosphate flame retardants were commonly detected wastewater indicators at all three sampled parks.

Simazine had the highest observed concentration among herbicides (>1000 ng/L) in two samples, both from Indiana Dunes. Those two, along with concentrations of metolachlor, another herbicide, at Mississippi River, were similar to concentrations reported for other major urban rivers in the United States. None of the samples exceeded the Maximum Contaminant Levels for herbicides in drinking water set by the USEPA.

With the exception of a few chemicals, detected concentrations were generally far below screening values or benchmarks at which human health can be affected. The exceptions were metformin, atrazine, and simazine, which each had concentrations approaching available human-health benchmarks in at least one sample, and hydrochlorothiazide (a diuretic medication), which exceeded a human health-based screening value in seven samples.

Management Implications

Data from this study will help us to establish a baseline for chemicals of concern in Midwestern national parks and highlight the need to better understand where these chemicals come from, how they get into our surface waters, and what effects they can have on aquatic systems in national parks.

In the meantime, the work continues. We collected samples from inland lakes at Pictured Rocks and Sleeping Bear Dunes national lakeshores in 2016, and we hope to collect samples in 2017 from Voyageurs National Park and Grand Portage National Monument.

**For more information: **Elliott, S.M., and D.D. VanderMeulen. 2016. A regional assessment of chemicals of concern in surface waters of four Midwestern United States national parks. Science of The Total Environment. DOI: http://dx.doi.org/10.1016/j.scitotenv.2016.11.114.

Where this belongs

• Apostle Islands National Lakeshore
• Indiana Dunes National Park
• Isle Royale National Park
• Mississippi National River & Recreation Area

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