Assessment of 40-year Al Deposition in some Exotic Conifer Species in the Urban Air of Düzce, Türkiye

Heavy metal (HM) pollution in urban air, a global dilemma, has increased drastically in the last century. Aluminum (Al) is one of the HMs and a neurotoxic element that can be absorbed into human tissues through digestion, breathing, and skin. Al accumulation in humans can cause diseases and even cause death. Due to the risks it poses to human and environmental health, it is vital to track the Al contamination shifts in the airborne and decrease them. In this study, 40-year Al concentration differences in Pseudotsuga menziesii, Cedrus atlantica, Picea orientalis, Cupressus arizonica, and Pinus pinaster grown in Düzce, Türkiye, the fifth most polluted European town, in terms of direction, tree species, and tissue type were assessed. As a result, Al accumulation in the tissues generally varies as outer bark > inner bark > wood. Whole species can accumulate Al significantly, and Al transfer between adjacent cells in the wood part is limited. In conclusion, all species can be used as biomonitors to track temporal Al pollution changes. However, the highest concentrations, especially in the wood part, were observed in Cedrus atlantica, Picea orientalis, and Cupressus arizonica, and these species were chosen to be the most suitable species to be used in phytoremediation studies.