**Background:** Rare earth elements (REE), including lanthanides, scandium (Sc), and yttrium (Y), are increasingly used in modern technologies and may enter forest soils via coal fly ash, sewage sludge, and phosphorus fertilizers. Knowledge of REE occurrence in edible wild mushrooms is limited due to trace-level concentrations and past analytical challenges. Cantharellus cibarius (golden chanterelle) is a popular wild food across Europe, yet data on its REE content are scarce. No prior data exist for C. minor.
**Methods:** A total of 2235 fruiting bodies of C. cibarius were collected from 22 locations across Poland between July–September of 1998–2008 and pooled into 22 composite samples. A single pooled sample of C. minor (153 specimens) was collected from the Caoba site in Yuxi Prefecture, Yunnan, China in July 2013. Mushrooms were cleaned, dehydrated at 65°C, ground in a ceramic mortar, and digested with nitric acid and hydrogen peroxide in a microwave-assisted closed-vessel system. Elemental analysis was performed using inductively coupled plasma–quadrupole mass spectrometry (ICP-MS, Elan DRCII, PerkinElmer). Internal standards (Rh and Ir) were used, and accuracy was checked against NIST-1573a Tomato leaves and IC-INCT-PVLT-6 Tobacco leaves reference materials. Recovery percentages ranged from 55% (Yb) to 123% (Gd).
**Key Results:** In C. cibarius, Sc was <1 µg kg⁻¹ dw at 20 of 22 sites, with detectable values of 17 µg kg⁻¹ dw (Tatra Mountains/Zakopane) and 27 µg kg⁻¹ dw (Tuchola Pinewoods/Lubichowo). Yttrium was detected in all composites (median 22 µg kg⁻¹ dw; range 16–83 µg kg⁻¹ dw). Median concentrations of the 14 REE were: La 27, Ce 35, Pr 2.3, Nd 9.2, Sm 3.1, Eu 0.5, Gd 2.2, Tb 0.5, Dy 2.0, Ho 0.5, Er 2.5, Tm 0.5, Yb 0.5, and Lu 0.5 µg kg⁻¹ dw. The sum of REE (ΣREE) across Polish sites ranged from 10.5 µg kg⁻¹ dw (Ciechocinek, Kujawy) to 592.8 µg kg⁻¹ dw (Tatra Mountains, Zakopane), with a mean of 143.7 ± 147.8 µg kg⁻¹ dw and median of 77.2 µg kg⁻¹ dw. Ce, La, and Nd together accounted for 92% of total REE (42%, 35%, and 12%, respectively). Six sites showed ΣREE above 200 µg kg⁻¹ dw: Coastal Landscape Park (204.9), Kaszubski Landscape Park (229.8), Tuchola Pinewoods/Lubichowo (504.8), Augustowska Primeval Forest (260.8), Świetokrzyskie/Włoszowa (206.2), and Tatra Mountains/Zakopane (592.8). The C. minor sample from Yunnan showed substantially higher concentrations: Sc 66, Y 200, La 480, Ce 940, Pr 95, Nd 360, Sm 58, Eu 9.6, Gd 56, Tb 2.5, Dy 34, Ho 5.7, Er 18, Tm 1.6, Yb 11, Lu <1.0 µg kg⁻¹ dw, with ΣREE of 2071.9 µg kg⁻¹ dw. Shale-normalized patterns (NASC, PAAS, European Shale, World Shale) showed negative anomalies predominantly in middle and heavy REE, particularly Yb, for most Polish sites, while C. minor showed anomalies for Tb and possibly Lu.
**Clinical Implications:** The concentrations of REE in C. cibarius from Poland are very low (median ΣREE 77.2 µg kg⁻¹ dw), and dietary exposure through consumption of this popular wild mushroom is negligible. Calcium content in C. cibarius (median 100–520 mg kg⁻¹ dw) exceeds REE content by approximately three orders of magnitude. REE are not essential for human nutrition, and although some (e.g., lanthanum) can mimic calcium in biological systems, the trace levels found in these mushrooms pose no identifiable health risk. The higher REE content in C. minor from Yunnan reflects the known polymetallic soil background of that region and warrants further investigation. The study underscores the importance of rigorous analytical methods (adequate sample size, clean-up from soil particles, proper instrumentation) to avoid overestimation of REE in mushrooms.