Interannual Variability of Heavy Metal Pollution in the Aktau Region of Kazakhstan

The purpose of these studies is to investigate the dynamics of heavy metal pollution in the coastal zone and the marine part of the Caspian Sea in the Aktau Region of Kazakhstan in order to monitor the ecological state of the environment. Copper, nickel, arsenic, cadmium, chromium, lead and zinc concentrations have been detected in soil samples. Chromium, copper, nickel, lead and zinc concentrations have been detected in seawater samples. Physico-chemical analyses of soil and seawater samples taken in the coastal zone and the marine part of the Aktau Region were carried out using atomic absorption spectrometer. Experimental data were collected in 2018, 2019, 2021, 2023 and 2024 to reveal the existing trends in heavy metal concentrations. As concerns, contamination of soils there was a serious decrease in heavy metal concentrations from 2018 to 2023. In seawater, a decrease of heavy metal concentrations has been observed by 2021-2023, but unexpectedly almost all elements showed a slight increase in 2024. Anyway, in 2023 and 2024, concentrations of all heavy metals in soil and seawater samples remain well below the Maximum Permissible Concentrations. A significant reduction in heavy metal pollution is probably due to a successful environmental policy aimed at reducing emissions of pollutants and improving treatment systems. The obtained results allow to build recommendations for sustainable resource management and use of the coastal zones and water areas in the Aktau Region for policy-makers and end-users.