The application of bio-indicators for the assessment of air pollution.

Levels of metals were assessed in topsoil, dust, leaves, grass, lichen and bark from the Kruger National Park using electrothermal atomic absorption techniques. It was found that dust, lichen and bark reflected the levels of air pollution better than grasses or leaves of trees. It is suggested that the difference in levels of accumulated metals in the bark or lichens could be used as an indicator of air pollution in remote areas.