Integrity of Lichen Cell Membranes in Relation to Concentration of Airborne Elements.

This study dealt with the impact of air pollution on the integrity of cell membranes in the lichen Ramalina duriaei. The lichen was transplanted from a relatively unpolluted site in Israel to more polluted sites, adjacent to a 40-year-old town, for a period of 10 months. The concentrations of K, B, Al, Cr, Fe, Si, Ti, Zn, P, Ba, Cu, Mg, Na, Pb, Ca, Mn, Sr, and S in lichen thalli were compared with injury caused to the cell membranes. The study indicates that electric conductivity reflects adequately cellular injury to lichen thalli transplanted to sites near a motorway, an oil-fueled power plant and a rural community (a kibbutz). The concentrations of S, B, Al, Cr, Fe, Si, Ti, and Zn correlated with injury in cell membranes of R. duriaei retrieved from the biomonitoring sites, whereas the concentration of K in the thalli correlated inversely with the electric conductivity parameter. Leakage of K from lichen thalli as a result of air pollutants is suggested. This K leakage correlates positively with concentrations of S and Cr in transplants of R. duriaei to the Ashdod region.