**Background:** Centaurium erythraea (Gentianaceae) is a medicinal plant used traditionally for digestive issues, diabetes, and wound healing, and is officially listed in pharmacopoeias of many countries. Despite its therapeutic value, little is known about its trace element content, especially when collected from polluted environments. The study aimed to determine trace element concentrations in C. erythraea from sites with varying pollution loads using INAA, and to assess potential health risks from consumption.
**Methods:** Ten sampling sites in Lower Silesia (SW Poland) were selected: three in the Bogatynia lignite basin (sites 1–3, 9), three near urban Wrocław (sites 6–8), two in rural areas near Bolesławiec (sites 4, 5), and one near the A4 highway (site 10). At each site, five leaf samples were collected randomly within a 25 m x 5 m square, each a mixture of three sub-samples (total n=50). Samples were dried at 40°C for 48 hours, ground, and pressed into pellets (~0.3 g). INAA was performed at the IBR-2 reactor (FLNP JINR, Dubna). Short irradiation (3 min, 15 min measurement) determined Al, Cl, Mn, V; long irradiation (4 days, neutron flux 1.8×10^11 cm^−2 s^−1) with two measurements (after 4 days for 30 min, after 20 days for 1.5 hours) determined As, Br, Fe, La, Mo, Sm, U, W, Ba, Ce, Co, Cr, Cs, Hf, Ni, Rb, Sb, Sc, Se, Sr, Tb, Th, Zn. Quality control used certified reference materials (NIST SRM 1573, 1575a, 1547, 1633b; IRMM BCR-667; NIST SRM 2710). Statistical analysis included co-variability estimation using the variations matrix T (log-ratio variances) and Pearson correlation, with significance assessed via t-test on log-transformed data. Daily intake of metals (DIM) and health risk index (HRI) were calculated using standard formulas (conversion factor 0.085, daily intake 0.345 kg/person/day, body weight 70 kg).
**Key Results:** The concentrations of 27 elements were determined. Compared to reference plant values (Markert et al.), most elements exceeded reference levels. For example, Al (mean 753 mg/kg vs. reference 80), As (0.91 vs. 0.1), Cl (2656.1 vs. 200), Fe (241.5 vs. 150), Se (0.3 vs. 0.02), Th (0.1 vs. 0.005), U (0.048 vs. 0.01). Elements within reference ranges included Ba (29.3 vs. 40), Cs (0.12 vs. 0.2), Mn (102.3 vs. 200), Ni (1.38 vs. 1.5), Rb (23.4 vs. 50), Sb (0.07 vs. 0.1), Sr (16.6 vs. 50), Tb (0.007 vs. 0.008). Plants from more polluted sites (MP: lignite basin, urban, highway) had significantly higher concentrations than less polluted (LP: rural) sites for most elements (t-test, p<0.05). For instance, Al (MP mean 846 vs. LP 436 mg/kg), Cr (1.79 vs. 0.85), Fe (267 vs. 78.6), Mn (111 vs. 45.9), Ni (1.6 vs. 0.49), Zn (65 vs. 23.5), As (1.1 vs. 0.2), Se (0.37 vs. 0.11), La (0.45 vs. 0.1), Ce (1.08 vs. 0.56), Th (0.13 vs. 0.015), U (0.07 vs. 0.017). Exceptions included Cl (LP 4100 vs. MP 2321, p<0.001) and Mo (LP 2.03 vs. MP 1.7, p=0.4). Co-variability analysis showed positive co-variability among many elements, especially rare earth elements (e.g., La–Sm, La–Tb, Sm–Tb) and microelements (Co, Cr, Fe, Mn, Se, V, Zn). Negative co-variability was rare (only four pairs, including two with Cl). Daily intake of metals (DIM) was higher for MP sites (e.g., Fe: 110 vs. 33 mg/kg; Zn: 30 vs. 10; Se: 0.2 vs. 0.05). Health risk index (HRI) values for MP sites were: Cr 0.05, Ni 3, Zn 9, Cu 13, Cd 8; for LP sites: Cr 0.02, Ni 1, Zn 3, Cu 8, Cd 2. HRI >1 indicates potential risk; thus, Ni, Zn, Cu, and Cd exceeded 1 for both MP and LP sites, while Cr remained below 1.
**Clinical Implications:** C. erythraea contains essential microelements (Co, Cr, Fe, Mn, Mo, Ni, Se, V, Zn) that could contribute to human nutrition, particularly Fe for anemia prevention, Co for vitamin B12 synthesis, Se for potential anti-tumor effects, and Zn for immune function. However, plants from polluted sites showed elevated levels of potentially toxic elements (Al, As, Cd, Ni, Pb, Sb). Although As and Cr concentrations did not exceed WHO/NSF permissible limits (As 5 mg/kg, Cr 2 mg/kg), HRI values for Ni, Zn, Cu, and Cd exceeded 1, indicating possible health risk over a lifetime of consumption. The study emphasizes the need for monitoring trace element content in wild-collected medicinal plants, especially from polluted areas, to ensure safety in herbal products. The lack of global regulations for maximum allowable levels in medicinal plants (except Cd and Pb by WHO) underscores the importance of such analyses for quality control in pharmaceutical production.