Lichens and heavy metals in the environment

After defining the categories of lichens according to their response to air pollution, the effects of heavy metals ions on lichen physiology and hence on their occurrence is discussed. This is illustrated by photographic examples of the toxic effects of zinc, lead and copper ion leachates on lichens. Further sections present information on: the contribution of the substrate to the accumulation of heavy metals; bioaccumulation of airborne heavy metals emitted by motor vehicles; the dependence of the heavy metal content on topography; biomonitoring of airborne heavy metals around metal smelters, power plants and other point sources; accumulation of heavy metals exposed to urban pollution and in sites contaminated by general industry; and large-scale monitoring of heavy metals in rural regions and unpopulated regions. -J.W.Cooper