Large scale atmospheric contribution of trace elements registered in foliose lichens in remote French areas

The human activities affect atmospheric compartment by trace elements emissions. The evaluation of atmospheric deposition can be performed by means of bioaccumulator organisms. In this study, we investigated two lichen species (Xanthoria parietina and Parmelia sulcata) from five remote areas far from local sources of contamination in France. PCA and enrichment factor were used to set up the geochemical background of 16 trace elements (including metals and metalloids). Some elements known to be influenced by anthropogenic activities, merge into the geochemical background, like As. The enrichment factors showed a high enrichment for Sb, Cd, Zn, As, Cu, and Pb, and to a less extent Sn and Mn. Others elements were associated to lithogenic contribution, including particularly As. A significant gradient from the South to the North-East was observed, convergently to the increased concentration registered in soils.