People and industries use tens of thousands of unregulated chemicals in industrial and household products and applications. In the late 1990s, scientists began developing new methods to test for unregulated chemicals in the environment. The resulting research shows a vast array of previously unrecognized chemical contaminants in the environment. Most of these contaminants have not been evaluated for the risks they might pose to ecosystems, to plants, fish, wildlife — or to us, which is why we call them contaminants of emerging concern or CECs.
Studies of Minnesota’s waters show that CECs, including pharmaceuticals, fragrances, fire retardants, detergents, insecticides, and industrial chemicals, are widespread in the state’s lakes and rivers. CECs get into lakes and streams through stormwater runoff, municipal wastewater discharges, septic systems, runoff from animal agriculture, and even rain and snow.
Endocrine active compounds
Some CECs are very similar to hormones, which regulate many aspects of an organism’s functions. CECs with endocrine-active properties can mimic the effects of hormones and harm the normal functioning, growth, and reproduction of an organism. These impacts can occur at very low concentrations and have been noted in several aquatic species such as fish and alligators. National and statewide studies have revealed that CECs with endocrine-active properties are widely present in the aquatic environment.
CECs in drinking water
The Minnesota Department of Health evaluates how Minnesotans might be exposed to CECs and the potential health impacts of CECs in drinking water. MDH develops health-based guidance for CECs that could be in water used for drinking, and provides risk context through outreach and education. This work includes developing methods for assessing CECs that are poorly studied, to help the state to respond to new environmental hazards.
Learn how to avoid or reduce your use of toxic products.
Aquatic toxicity profiles
The effects of CECs on fish, wildlife, and humans are only partly understood. The MPCA has been collecting occurrence data for a diverse set of CECs, but toxicity data and regulatory or screening values for many of these contaminants don't exist. The agency has developed a screening method — aquatic toxicity profiles — to prioritize those that are most likely to have adverse effects on aquatic life.
Aquatic toxicity profiles will help us prioritize contaminants for monitoring, plan more effective and targeted monitoring studies, identify contaminants that may be good candidates for water quality standards, determine which contaminants would be good candidates for pollution prevention efforts, and communicate risk to the public.
Each profile consists of:
- The technical information used to determine the priority — or level of concern — of each contaminant
- An overview of the concerns related to each contaminant
In a large 2017 study of Minnesota’s lakes, a total of 55 of the 163 chemicals tested were found in at least one of the 50 lakes tested. Even in remote areas of the state, tests revealed chemicals such as antibiotics, nicotine breakdown products, antidepressants, and medications to regulate diabetes, cholesterol, and blood pressure. The insect repellent DEET was very frequently detected, together with the hormone estrone, several medicines, and the breakdown products of detergents. This is the second study of a random selection of 50 lakes in Minnesota. The results are consistent with those of previous studies of Minnesota lakes and rivers.
- Pharmaceuticals and chemicals of concern in Minnesota lakes (tdr-g1-21)
- Pharmaceuticals and chemicals of concern in Minnesota lakes: Appendix E - Report analytical tables (tdr-g1-21a)
- Pharmaceuticals and chemicals of concern in rivers: Occurrence and biological effects (tdr-g1-20)
- Pharmaceuticals, personal care products and endocrine active chemical monitoring in lakes and rivers - 2013 (tdr-g1-18)
- Pharmaceuticals and endocrine active chemicals in Minnesota lakes (tdr-g1-16)
- Pharmaceuticals and personal care products in Minnesota’s rivers and streams - 2010 ( tdr-g1-17)
- Endocrine active chemicals and other contaminants of emerging concern in Minnesota’s groundwater, 2009-2010 (wq-cm4-03)
- Statewide endocrine disrupting compound monitoring study, 2007-2008 (tdr-g1-08)
- Endocrine Active Compound Monitoring in Minnesota Lakes, 2009-2011 - Lake Habitat and Land Use (tdr-g1-08b)
- Endocrine Disrupting Chemicals in Minnesota Lakes—Water-Quality and Hydrological Data from 2008 and 2010 (USGS)
- Steroidal Hormones and Other Related Compounds in Shallow Groundwater in Nonagricultural Areas of Minnesota—Study Design, Methods, and Data, 2009–10 (USGS)
- Endocrine Active Chemicals, Pharmaceuticals, and Other Chemicals of Concern in Surface Water, Wastewater-Treatment Plant Effluent, and Bed Sediment, and Biological Characteristics in Selected Streams, Minnesota—Design, Methods, and Data, 2009 (USGS)
- Anthropogenic tracers, endocrine disrupting chemicals, and endocrine disruption in Minnesota lakes (USGS)
- Alkylphenols, Other Endocrine-Active Chemicals, and Fish Responses in Three Streams in Minnesota—Study Design and Data, February–September 2007 (USGS)
- Occurrence of Endocrine Active Compounds and Biological Responses in the Mississippi River—Study Design and Data, June through August 2006 (USGS)