Trace, technology-critical, and rare earth element data from six boreal lakes near Rouyn-Noranda [Québec, Canada, 2019–2023]

Lakes were selected along a gradient of contamination associated with historical mining and smelting activities, including the Horne Smelter (nearby, intermediate, and distant lakes). Water, sediments, and fish tissues (muscle and liver) were sampled to measure trace elements (TEs), technology-critical elements (TCEs), and rare earth elements (REEs).

Water samples were collected from the epilimnion at multiple locations per lake, while sediment samples were taken from the top 2–3 cm of the lakebed. Fish (walleye and yellow perch) were captured using gillnets, and morphometric data were recorded before sampling liver and muscle tissues. Trace element concentrations were measured using triple quadrupole ICP-MS, and data were compared with Canadian environmental quality guidelines for water and sediment, as well as FAO/WHO guidelines for fish consumption.