Evaluation of potentially toxic elements and 137Cs deposition in Polesie State Radiation and Ecological Reserve, Belarus using moss biomonitoring technique.

The Polesie State Radiation and Ecological Reserve, which encompasses the Belarusian sector of the Chernobyl Exclusion Zone, provides a critical natural laboratory for studying long-term environmental contamination. This investigation utilized the moss as a bioindicator to evaluate the spatial distribution of potentially toxic elements, Al, Ba, Co, Cd, Cr, Cu, Fe, Mn, P, Pb, Sr, V, S, Zn, Ni, and Hg, and the radionuclide 13⁷Cs across the reserve. The results demonstrate significant spatial heterogeneity in contaminant distribution, with 13⁷Cs activity concentrations ranging over two orders of magnitude (385-44,300 Bq/kg). Multivariate approaches (factor and correlation analyses) revealed distinct geochemical signatures: crustal elements (Al-Fe-Cr-V-Co-Ba-Sr-Mn) associated with natural soil composition, possible contaminants (Cu-Zn-Cd-Pb-S-P-Hg-Ni) reflecting anthropogenic legacy, and 13⁷Cs showing independent behavior. The calculated ecological indices, including the Contamination Factor, Pollution Load Index, and Enrichment Factor, revealed the presence of localized hotspots with moderate to severe levels of contamination (CF: 2-10.3 for Cd, Pb, V, Mn; PLI: 0.8-1.3; EF > 10 for Mn, P, Hg, Zn, Cu), highlighting residual anthropogenic influences. These findings demonstrate moss biomonitoring as an effective tool for assessing radioactive and elemental contamination, providing valuable insights for ecological risk management in post-accident environments.