Studies of Minnesota’s waters show that a wide variety of unregulated chemicals, such as pharmaceuticals, fragrances, fire retardants, detergents, and insecticides, are widespread in the state’s lakes and rivers.
Some of these contaminants are hormones, or chemicals known to mimic the effects of hormones in animals and cause changes to the reproductive system or to the growth and development of an organism. These "endocrine active" chemicals (EACs) may not exhibit acute toxicity at the levels normally found in the environment, but instead negatively affect the normal functioning, growth, and reproduction of an organism at very low concentrations.
Sources of these chemicals to surface water include municipal wastewater discharges, septic systems, runoff from animal agriculture, storm water, and even rain and snow.
Although the effects of most of these chemicals on fish, wildlife, and humans are not yet completely understood, the MPCA has developed a screening method — aquatic toxicity profiles — to prioritize those that are most likely to have adverse effects on aquatic life.
Endocrine-active compounds
Some chemicals can mimic the effects of hormones in animals and cause adverse physiologic effects, such as changes to the reproductive system or to the growth and development of an organism. These chemicals are called "endocrine active" compounds (EACs). These compounds do not usually exhibit acute toxicity at the levels normally found in the environment, but instead can alter the normal functioning and growth of the exposed organism at very low concentrations.
In the last decade, national and statewide studies have revealed that many chemicals with known or suggested endocrine-disrupting potential are found in the aquatic environment. These chemicals include pharmaceuticals, personal care products, chemicals associated with wastewater effluent, and a variety of industrial compounds. Apart from the disquieting realization that wastewater chemicals and drugs are detectable in much of our surface water, there is a growing concern that even at low concentrations, chemicals, or mixtures of them, may adversely affect fish, wildlife, ecosystems and possibly human health.
MPCA research
New report 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 sampled for this study. 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)
Older reports
- 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)
- Statewide Endocrine Disrupting Compound Monitoring Study, 2007-2008: Addendum (2010)
- Wastewater Treatment Plant Study, 2009-2011
- Wastewater Treatment Plant Endocrine Disrupting Chemical Monitoring Study
- Endocrine Active Compound Monitoring in Minnesota Lakes, 2009-2011 - Lake Habitat and Land Use
Other resources
- Report on Endocrine Disrupting Compounds (2008)
- Endocrine Disrupting Compounds
- Endocrine Active Chemicals and Other Contaminants of Emerging Concern in Minnesota’s Groundwater, 2009-2010
Endocrine Disrupting Chemicals in Minnesota Lakes — Water-Quality and Hydrological Data from 2008 and 2010- Steroidal Hormones and Other Related Compounds in Shallow Groundwater in Nonagricultural Areas of Minnesota—Study Design, Methods, and Data, 2009-2010
- 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
- Anthropogenic tracers, endocrine disrupting chemicals, and endocrine disruption in Minnesota lakes
- Alkylphenols, Other Endocrine-Active Chemicals, and Fish Responses in Three Streams in Minnesota — Study Design and Data, February–September 2007
- Occurrence of Endocrine Active Compounds and Biological Responses in the Mississippi River—Study Design and Data, June through August 2006