Determination of heavy metal accumulation in air through annual rings: The case of Malus floribunda species

Abstract

Air pollutants can be observed all over the world. Sulfur dioxide and nitrogen oxides are the most worrying ones among them. The growth rates of many forested areas in the world decrease at high altitudes, and air pollutants are more abundant as the cause of this. The leaf surface constitutes the interface between plants and the worsening atmospheric environment. Therefore, it is the first point of contact between plants and air pollutants and constitutes an effective barrier to the pollutant input. The outer surfaces of leaves are covered with a thin membrane called the cuticle. This membrane layer has many basic functions, such as preventing the excessive water loss of the plant, regulating the intake of dissolved substance and protecting photosynthetic tissues, preventing of harmful irradiation, such as improved UV-B caused by stratospheric ozone depletion. The wood structure also provides us with information on the pollutants to which they are exposed to and their levels due to the fact that trees are stationary. In this study, the accumulations of Co, Cu, Cd, Pb, Ni, Cr, Mn, Fe, Al, Zn, Na, Ca, Ba, Mg, and As elements, accumulated on the annual rings of Malus floribunda species in Ankara-Yenimahalle between 1962 and 2017, by years were determined using the GBC Integra XL-SDS-270 ICP-OES device. In conclusion, it is observed that amounts of all elements in the wood in different age ranges are statistically different at a confidence level of at least 99.9%.