Assessment of atmospheric pollution by heavy metals using transplanted lichen Pseudevernia furfuracea (L.) Zopf in Niğde Province, Türkiye

Abstract

Lichens have been demonstrated to be vulnerable to air pollution for more than 140 years, since pollutants have been shown to impact crucial metabolic processes in both algae and fungus. Lichens serve as bioindicators for air pollution levels in different places by collecting air pollutants in their thallus, including heavy metals, polycyclic aromatic hydrocarbons (PAHs), and sulfur dioxide (SO2). This study involved collecting samples of Pseudevernia furfuracea (L.) Zopf from a pristine forest region (Yapraklı-Çankırı) and transplanting them for two periods of three months each at six locations surrounding the polluted Niğde provincial center in Turkey. This research aimed to analyze the concentrations of Cu, Cd, Ni, Pb, Mn, and Zn by the use of Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In addition, we computed the levels of chlorophyll a and b, and also determined the proportions of chlorophyll a+b, a/b, and b/a. Furthermore, a pollution map of the city was created. According to analysis results for P. furfuracea means of heavy metals; in first period 0.36μg g−1, 0,032μg g−1, 0,44μg g−1, 0,70μg g−1, 1,94μg g−1, 0,2 μg g−1; in second period 0,58μg g−1, 0,033μg g−1, 0,36μg g−1 ,0,92μg g−1 , 1,98μg g−1 , 0,65μg g−1 for Cu, Cd, Ni, Pb, Mn, Zn. Whereas means of control stations are 0,26 μg g−1, 0,028 μg g−1, 0,23μg g−1, 0,52μg g−1,1,90μg g−1, 0,16μg g−1, in 1st period; 0,36 μg g−1, 0,027μg g−1,0,29 μg g−1, 0,56μg g−1, 1,96μg g−1, 0,58 μg g−1 in 2nd period for for Cu, Cd, Ni, Pb, Mn, Zn. The factors that contribute to high heavy metal levels are as follows: (i) traffic density, (ii) industrial activities, (iii) urban heating activities. Despite the survey's short duration, P. furfuracea was proved to be an efficient bioaccumulator organism for further biomonitoring researches.