Research roundup: How are contaminants getting into Minnesota lakes?
A team of researchers, led by Tiffany Wolf, DVM, PhD, assistant professor in the Department of Veterinary Population Medicine at the University of Minnesota College of Veterinary Medicine (CVM), and Seth Moore, PhD, director of biology and environment at the Grand Portage Band of Lake Superior Chippewa, recently published studies that prioritized contaminants of emerging concern (CECs) based on their potential environmental threat and evaluated human activities and environmental factors’ effects on CEC presence in Minnesota lakes. CECs include medications, personal care products, and hormones and are becoming an increasing threat to aquatic environments in both rural and populated areas around the state. Researchers are looking to understand the specific sources and pathways of CECs, as well as the short and long-term effects of these contaminants on human and fish health. Over three years, the researchers collected and analyzed samples of sediment, water, and fish from inland lakes and Lake Superior. In the first phase of the study, researchers used a hazard prioritization process adapted from the Minnesota Pollution Control Agency. Called the Aquatic Toxicity Profile, this framework gave the 117 CECs scores based on each contaminant’s toxicity, accumulation potential, and how frequently the scientists detected each CEC. In phase two of the study, the researchers evaluated 21 inland lakes relied on by indigenous communities for subsistence in order to determine how surrounding land use — including road surfaces, wastewater treatment, and health care facilities — corresponded with CEC presence. The scientists found 50 high-priority contaminants in water samples, 21 in sediment samples, and seven in fish. They also found an overall association between human land use and contaminant presence, particularly infrastructure with impervious surfaces such as roads, parking lots, and buildings. This research can inform future CEC detection and management and sustaining surrounding communities. These studies further identify additional areas where this type of framework and statistical analysis can be deployed. Future research directions for this team will focus on toxicity testing on subsistence fish species of Minnesota Chippewa in a laboratory setting and environmental studies on a newly discovered tire chemical that causes mortality in coho salmon.