Biomonitoring of air pollution in Cluj-Napoca city using tree leaves

Air pollution associated with urbanization and traffic emissions represents a major environmental concern in urban areas. Urban vegetation can accumulate airborne particulate matter and associated metals, providing valuable information on the spatial distribution of atmospheric pollution. Tree species with different leaf morphologies have distinct accumulation capacities, making them useful indicators of local environmental quality. This study aimed to assess the accumulation of Cu, Pb, Zn, Cd, Cr and Ni in white cedar (Thuja occidentalis) and black poplar (Populus nigra) leaves collected from Cluj-Napoca city characterized by different anthropogenic influences. White cedar and poplar leaf samples were collected from 6 different sits in Cluj-Napoca influenced by road traffic and residential activities were collected. The concentrations of metals were determined using inductively coupled plasma mass spectrometry after microwave-assisted acid digestion. The results showed that Pb and Cr concentrations in white cedar leaves, were relatively uniform among sampling sites, whereas Cu, Zn, and Ni concentrations were significantly higher with intense traffic, indicating the influence of vehicular emissions. In contrast, metal concentrations in poplar leaves exhibited showed higher spatial variability, Zn being accumulated dominantly. For both species, none of the metals reached phytotoxic levels. The obtained results suggests that the leaves of white cedar and black poplar are effective biomonitoring tools for assessing urban air quality and traffic-related pollution.

Acknowledgement: This research was carried out through the Core Program within the National Research Development and Innovation Plan 2022–2027, with the support of MCID, project PN no. 23 05.