Review of the role of elemental and isotopic composition of lichens in air quality assessment

This review focuses on the efficacy of lichens as biomonitors of atmospheric deposition. It emphasizes the function of lichens in the assessment of trace element pollution and trace element isotope determination in different environments. The importance of foliose and fruticose lichens in lichen biomonitoring, comparison of bulk deposition/aerosol concentrations with the concentrations of transplants and comparison of lichen species with particular reference to the literature of the last decade were investigated. Biomonitoring is a comparatively inexpensive and readily implementable alternative to conventional air sampling methods, although it is subject to certain limitations. While passive biomonitoring uses native organisms, active biomonitoring uses lichens that have been transplanted. The quantitative relationship between the concentrations of elements in lichens and the concentrations in total deposition or in aerosols could be obtained. The accumulation capacity of lichens is influenced by their morphology, substrate and environmental conditions. In addition, the evaluation of trace element isotopes is considered, particularly carbon, nitrogen, sulfur, mercury and lead isotopes, as these are crucial for source apportionment studies. As valuable organisms in environmental monitoring, lichens can contribute to strategies developed to protect public health.