Determination of heavy metal accumulation in air through annual rings: The case of Cupressus arizonica species

In recent years, increasing air pollution has reached important dimensions and has become one of the most important agenda items. Heavy metals are the most relevant among the air pollution components. Since heavy metals do not disappear easily in nature, they tend to biodegrade and some have toxic or carcinogenic effects, even at low concentrations. Monitoring of changes in heavy metal concentrations in the air is therefore extremely important. Biomonitoring is the most preferred way to determine/follow the changes of heavy metal concentration in the atmosphere. Trees are good biomonitors to determine the concentration of heavy metals in the atmosphere in a long time. Annual rings of trees especially hold important information about the changes of heavy metal concentration in the air. This study aims to determine the change of some heavy metal concentrations in the tree rings of a 21 years olds Cupressus arizonica tree that grows in the center of Kastamonu city. The heavy metal concentrations in the bark and inner bark were also compared with the heavy metal concentrations in the wood and this study also tried to determine the change of heavy metal concentration in the region by year and organelle. In the study, the element concentrations in the inner and outer bark were also determined. Thus the changes in the direction, organelle and year basis of the subject elements are to be determined in this study. As a result of the study, it is determined that the elemental concentrations in the outer bark generally have a higher level and that the change of the elements on a year-by-year basis generally follows a fluctuating course; however, there has been an increase in the concentration of some elements such as Cd, Ni, Fe, Ca, Mn and Pb in recent years.