Bioindication of Sulphur Dioxide Pollution with Lichens

Bioindicators are organisms that react to environmental pollution with their life functions (Arndt et al. 1987). According to (1970) and (1973) lichens can be used as bioindicators in the following methods: • Passive bioindication uses naturally occurring lichens for monitoring purposes. • Active bioindication involves collecting lichens in areas with clean air, moving them to polluted areas then testing for the effects of air pollution. • Reactive bioindicators respond to air pollution and other stress with their life functions (e.g. growth, structure, distribution). • Accumulative bioindicators are organisms that accumulate pollutants without significant damage to their life functions, at least up to a certain dose of pollutant.