Use of Leaves as Bioindicator to Assess Air Pollution Based on Composite Proxy Measure (APTI), Dust Amount and Elemental Concentration of Metals

Abstract

Monitoring air pollution and environmental health are crucial to ensure viable cities. We assessed the usefulness of the Air Pollution Tolerance Index (APTI) as a composite index of environmental health. Fine and coarse dust amount and elemental concentrations of Celtis occidentalis and Tilia × europaea leaves were measured in June and September at three sampling sites (urban, industrial, and rural) in Debrecen city (Hungary) to assess the usefulness of APTI. The correlation between APTI values and dust amount and elemental concentrations was also studied. Fine dust, total chlorophyll, and elemental concentrations were the most sensitive indicators of pollution. Based on the high chlorophyll and low elemental concentration of tree leaves, the rural site was the least disturbed by anthropogenic activities, as expected. We demonstrated that fine and coarse dust amount and elemental concentrations of urban tree leaves are especially useful for urban air quality monitoring. Correlations between APTI and other measured parameters were also found. Both C. occidentalis and T. europaea were sensitive to air pollution based on their APTI values. Thus, the APTI of tree leaves is an especially useful proxy measure of air pollution, as well as environmental health.

Usefulness of Tree Species as Urban Health Indicators

“…The amount of fine dust was measured using the gravimetric method; filter papers were weighed before and after filtration to determine the amount of dust collected on the paper. The amount of dust was determined in µg cm −2 , as in mass per area of the leaf's surface [7][8][9].…”

“…The accumulation of contaminants by plants is widely documented [6][7][8][9][10]. Trees are particularly efficient in trapping dust-reducing airborne particles deposited in tree leaves' stomatal openings and waxy cuticles [11].…”

Use of Black Poplar Leaves for the Biomonitoring of Air Pollution in an Urban Agglomeration

“…Air pollution is recognized as one of the factors that decrease life expectancy and increase the incidence of cardiovascular and respiratory pathologies as the fine and ultrafine particulates can penetrate deeply into the lungs [ 5 , 6 ]. Air pollution with particulate matter (PM), with aerodynamic diameters <10 µm (PM 10 ), 2.5 μm (PM 2.5 ), and 1 μm (PM 1 ) are the main challenges, especially in urban agglomerations, where besides the industrial activities, vehicular traffic (exhaust emissions, tire and brake wear, mechanical frictions, and lubricants), surface runoff, re-suspended dust, and fossil fuel combustion are considered important pollution sources [ 7 , 8 , 9 ]. Depending on its diameter, PM released into the atmosphere can travel high distances, has a high airborne lifetime, and may suffer various transformations [ 10 ].…”

“…The suitability of poplar leaves to reflect the atmospheric Hg contamination was reported by Assad et al [ 21 ]. Molnar et al used common hackberry ( Celtis occidentalis ) and common lime ( Tilia x europaea ) leaves to assess the level of air pollution (in urban, industrial, and rural areas of Debrecen, Hungary [ 9 ].…”

Using Fractionation Profile of Potentially Toxic Elements in Soils to Investigate Their Accumulation in Tilia sp. Leaves in Urban Areas with Different Pollution Levels

“…This poses the question of how those compounds are redistributed and mobilized in the soil. Plants in urban ecosystems can reflect the PTEs' pollution both in soil and atmosphere, enabling the biomonitoring of pollution over long periods to quantify pollution parameters and identify the spatial and temporal distribution patterns of the pollutants [37][38][39]. In the case of trees, the PTEs uptake takes place in the leaves and roots and is controlled by the species characteristics, the concentration of metal, as well as the solubility and bioavailability of the metals [40,41].…”