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.
Studies of Minnesota’s waters show that contaminants of emerging concern (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.
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.
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.
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.
- Additional reports and studies can be found in the MPCA library.