LICHENS AS SPECIFIC AND COST-EFFECTIVE BIOLOGICAL INDICATORS OF URBAN CARBON MONOXIDE CONCENTRATION.

The use of biological indicators provides economically justified, cumulative and rapid insight into pollution-related load in the air. Furthermore, lichens are specific pollutants and give accurate results without the use of an expensive technology. Although their distribution and abundance are known to be affected by high environmental sulphur SO₂ (dioxide) concentrations, the results of this study show that such effects are possible without the impact of SO₂. Nine lichen genera were examined over a period of six months at ten locations in Novi Sad (Serbia), chosen by significant differences in urbanisation. The relative abundance of lichen populations and environmental concentrations of SO₂ and carbon monoxide (CO) were determined at each location, once a week during the six-month period. A total of 1040 air samples were analysed (780 CO analyses and 260 SO₂ analyses). The SO₂ concentrations were found to be far below the recommended exposure limits throughout the study. The spatial distribution and abundance of lichens were found to be inversely proportional to the CO concentration in the air. [ABSTRACT FROM AUTHOR]