Variations in Barium Concentrations Over Time in Regions with Elevated Air Pollution

Heavy metals are one of the most important pollution factors threatening the environment and people’s health today. Barium, one of the most widely used heavy metals, is among the most dangerous regarding the environment and human health; all its compounds are poisonous. Therefore, monitoring and decreasing barium pollution are among the priority research topics. This study aimed to evaluate barium sources in Düzce, identify suitable biomonitor species for monitoring changes in barium pollution, determine the parts of tree stems where barium accumulates most, and assess changes in barium levels over 60 years. Within the scope of the study, samples taken from Tilia tomentosa, Robinia pseudoacacia, Cedrus atlantica, Pseudotsuga menziesii, and Fraxinus excelsior species growing in Düzce, which is among the five most polluted cities in Europe according to the World Air Pollution Report, were examined. Changes in barium concentrations over the past 60 years were assessed based on species, direction, organs, and range of age. As a result, barium concentrations in R. pseudoacacia, P. menziesii, and C. atlantica species were below detectable boundaries. It was determined that the primary sources of barium pollution are traffic and urban areas. It was also determined that F. excelsior is the only species suitable as a biomonitor among the species studied, that barium accumulates most in the outer bark of tree stems, and that there has been a significant increase in barium concentration in recent years.

Cite this article as: İsmail, M. D., Ko., İ., Erdem, R., Çobanoğlu, H., & Sevik, H. (2026). Variations in barium concentrations over time in regions with elevated air pollution. Forestist, 76, 0010, doi:10.5152/forestist.2026.25010.