Environmental monitoring is an essential step in any economical and social development policy. The atmospheric pollution study is a principal task due to the importance of atmospheric transfer of pollutants. Geographically, Morocco is characterized by different micro-climates influencing, on one hand, the transfer range of trace elements and, on the other hand, the availability of biological organisms that can be used in trace element air pollution biodetection study. Tree-barks, lichens and mosses were used in this study to evaluate trace elements bioavailability in different regions of Morocco. Those organisms were analyzed using the multi-elemental k0-INAA technique. The quality control of the results was performed by the analysis of reference materials. The analysis results were interpreted in the form of enrichment factors reflecting the atmospheric availability of anthropogenic pollutant elements such as Cl, V, Cr, Zn, As, Se and Sr.