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.

Table1. Detection frequency and maximum concentration of detected wastewater indicators analyzed in a subset of samples in 2013 and 2014.

Chemical	Chemical Class	Detection Frequency (%)	Maximum Concentration (ng/L)
Mississippi National River and Recreation Area (2013)
Bisphenol A	Plastic component	50	232
Caffeine	Stimulant	50	43.3
Galaxolide	Synethetic fragrance	33	115
Metolachlor	Herbicide	17	867
Tributyl phosphate	Plasticizer/flame retardant	33	68.6
Triethyl citrate	Plasticizer	17	146
Apostle Islands National Lakeshore (2014)
Bisphenol A	Plastic component	12	56.2
Tri(dichloroisopropyl) phosphate	Plasticizer/flame retardant	12	50.9
Triclosan	Antimicrobial	12	74.9
Indiana Dunes National Lakeshore (2014)
Acetophenone	Fragrance	40	67.7
Bisphenol A	Plastic component	40	350
Caffeine	Stimulant	20	215
Camphor	Fragrance	20	89.6
Equilenin	Estrogen	20	187
Estrone	Estrogen	20	121
Methylsalicylate	Fragrance	20	53.4
Triphenyl phosophate	Plasticizer/flame retardant	20	82

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.

Table 2. Detection frequency and maximum concentration of pharmaceuticals, personal care products, and pesticides detected in at least 30% of samples collected at each national park.

Chemical	Chemical Class	Detection Frequency (%)	Maximum Concentration (ng/L)
Mississippi National River and Recreation Area (2013-2014)
2,4-Dichlorophenoxyacetic acid	Herbicide	100	172
Acetochlor	Herbicide	50	265
Acetochlor oxanilic acid	Herbicide by-product	95	896
Atenolol	Medication (blood pressure)	35	30.5
Atrazine	Herbicide	100	302
Atrazine de-ethyl	Herbicide by-product	30	56.8
Bentazon	Herbicide	30	12.6
Caffeine	Stimulant	55	43.3
N,N-diethyl-3-methylbenzamide (DEET)	Insecticide	60	251
Desmethylvenlafaxine	Medication (antidepressant)	65	74.7
Dimethenamid	Herbicide	45	119
Dimethenamid ethanesulfonic acid	Herbicide by-product	35	107
Gabapentin	Medication (anticonvulsant)	100	1080
Gemfibrozil	Medication (cholesterol mgmt)	35	27.5
Hydrochlorothiazide	Medication (diuretic)	55	67.8
Hydroxybupropion	Medication (antidepressant metabolite)	40	42.6
Imazethapyr	Herbicide	70	198
Lamotrigine	Medication (anticonvulsant)	65	85.2
Metformin	Medication (antidiabetic)	100	150
Metolachlor	Herbicide	65	867
Metolachlor sulfonic acid	Herbicide by-product	100	555
Ranitidine	Medication (antacid)	42	33.1
Sulfamethoxazole	Medication (antibiotic)	55	77.7
Tramadol	Medication (opioid, pain reliever)	30	28.2
Apostle Islands National Lakeshore (2014)
Gabapentin	Medication (anticonvulsant)	30	13.7
Isle Royale National Park (2015)
Atrazine	Herbicide	38	14.6
N,N-diethyl-3-methylbenzamide (DEET)	Insecticide	92	119
Indiana Dunes National Lakeshore (2014-2015)
2,4-Dichlorophenoxyacetic acid	Herbicide	58	179
Acetochlor oxanilic acid	Herbicide by-product	68	105
N,N-diethyl-3-methylbenzamide (DEET)	Insecticide	92	122
Gabapentin	Medication (anticonvulsant)	58	2790
Imazethapyr	Herbicide	42	492
Metformin	Medication (antidiabetic)	32	903
Metolachlor sulfonic acid	Herbicide by-product	100	1550
Simazine	Herbicide	34	3140
Triclopyr	Herbicide	39	581

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.