Anthropogenic gadolinium as a micropollutant in river waters in Pennsylvania and in Lake Erie, northeastern United States

“Anthropogenic” gadolinium, Gd, used in contrast agents in magnetic resonance imaging, is a micropollutant that enters river and lake waters with the discharge from wastewater treatment plants, WWTPs. Such discharge is also the source of other micropollutants, for example pharmaceuticals, such as steroids, antihistamins, and antibiotics. Together with the “natural” Gd, the anthropogenic Gd produces positive Gd anomalies in rare-earth element distribution patterns and is, therefore, easily detectable. This pilot study reports on the occurrence of anthropogenic Gd in rivers in Pennsylvania (Ohio, Beaver, Allegheny, Monongahela, Juniata, and Susquehanna) and in near-shore surface water from Lake Erie close to the city of Buffalo. Additional data are reported for the Delaware River and the headwaters of Spring Creek in Central Pennsylvania, and for Lake Ontario and Niagara River, all of which do not show significant anthropogenic Gd. Most pronounced impact of anthropogenic Gd discharged from WWTPs is observed in the Pittsburgh Metropolitan area. Such contamination is similar to that observed in densely populated areas with highly developed medical and healthcare systems in Europe and Japan. Its worldwide applicability adds to the promising potential of anthropogenic Gd as a cost-effective tracer for the presence of WWTP effluent in river, lake, ground, and drinking waters.