Temporal Dynamics and Sources of Heavy Metals in an Aquatic Ecosystem: An Applied Study

This study investigates the sources and distribution of heavy metals in the Styr River, particularly in the area influenced by the cooling water blowdown from the Rivne Nuclear Power Plant (Ukraine). The concentrations of eight heavy metals (Zn, Cd, Pb, Cu, Ni, Mn, As, and Cr) were measured over a period from 2018 to 2022. Monthly water samples were collected and analyzed using an inductively coupled plasma optical emission spectroscopy (ICAP 7400 Duo, Thermo Fisher Scientific, Waltham, MA, USA). The results show that the average concentrations (M ± SD) of the heavy metals decreased in the following order: Cu (6.43 ± 1.82 ppb), As (5.1 ± 0.2 ppb), Zn (4.67 ± 1.14 ppb), Mn (4.03 ± 2.81 ppb), Ni (3.3 ± 0.8 ppb), Cr (1.06 ± 0.22 ppb), Pb (1.05 ± 0.11 ppb), and Cd (1.01 ± 0.03 ppb). Seasonal and annual variations in metal concentrations were observed, with notable decreases in Zn, Cu, and Mn in 2021, likely due to anthropogenic activities. Pearson correlation analysis and cluster analysis were employed to explore relationships between the metals. The findings suggest that certain metals, such as Pb, Cr, and Ni, share common sources, likely industrial emissions or urban pollution, while others, such as Cd and As, have more isolated sources. This research highlights the complex interplay of natural and anthropogenic factors influencing heavy metal levels in the Styr River.