Lichens as quantitative biomonitors for atmospheric trace-element deposition, using transplants

At 8 stations spread over The Netherlands transplants of Parmelia sulcata Taylor and impregnated cloth (rag) as a non-biological monitor were exposed to the atmosphere for periods of up to 12 months. At the same stations bulk (wet and dry) deposition was collected on a monthly basis. Quantitative linear relationships between the concentrations in the 12 months exposed lichens and the cumulative bulk deposition during the same period, yielded accumulation factors for cobalt, scandium and zinc. The lichens reflected the bulk deposition. The ratios between the accumulation factors for cobalt, scandium and zinc in lichens and rag are comparable. This gave some insight in the uptake mechanism, probably mainly passive, such as particulate trapping, adsorption/desorption and/or ion exchange.