Variation of heavy metal concentrations and stomatal characters depending on traffic density in some plants grown in Pakistan

Today, one of the most important problems in the world is environmental and especially air pollution. Among the components of air pollution, especially heavy metals are of particular importance because they do not deteriorate and disappear easily in nature, can be toxic and carcinogenic to humans even at low concentrations, and bioaccumulate in living organisms. therefore, the detection of heavy metal concentrations in the air is extremely important. However, since the direct determination of heavy metal concentrations in the air is very difficult and expensive, biomonitors are often used for this purpose. Plants that live permanently in their region and can accumulate heavy metals in the air are suitable biomonitors that can be used to monitor heavy metal pollution in the air. However, plants accumulate different elements at different levels in their different organs, and therefore, it is necessary to determine separately which plant and organ is more suitable for monitoring which element. In this study, it was aimed to determine the change of heavy metal concentrations in some plants used extensively in Pakistan depending on traffic density. For this purpose, samples were taken from the leaves and branches of Ficus bengalensis, Ziziphus mauritiana, Conocarpus erectus and Azadirechta indica species, and washing was applied to some of the samples. Thus, 4 species, 2 organ washing conditions and 3 traffic densities were evaluated within the scope of the study, and the samples obtained were Ba, Cr, Mn, Ni, Cu, Zn, Pb, Al, Ca, Fe, K, Na, Mg with the help of the ICP-OES device. and the change of Sr elements were determined. Within the scope of the study, measurements were made on the images taken from the leaves with the help of SEM electron microscope, and the variation of stomatal length, stomatal width, pore size and pore width values depending on traffic density was determined. As a result of the study, a linear relationship was not established between the change of stomatal characters and the traffic density. Li, Co, and Cd, among the heavy metals evaluated within the scope of the study, were not included in the evaluation since they were below the detectable limits in all samples. On the other hand, it was determined that the changes in other heavy metals were statistically significant both on the basis of traffic density and on the basis of organs, and the most suitable species and organs were determined separately for monitoring the change of each heavy metal.