In the middle Soča valley there are many sources of air pollution. Important sources in winter are wood-burning fireplaces. In this area Salonit Anhovo is located where carcinogenic asbestos was processed in the past. Now it is a cement and co-incineration plant. Air pollution has been monitored by the accumulation of air particles on the surface of mosses and by filtering the air with an air pump. Sampling took place during the heating and non-heating periods. Four moss species were used: Sphagnum capillifolium (Ehrh.) Hedw., Polytrichum formosum (Hedw.), Pseudoscleropodium purum (Hedw.) Fleischer in Hylocomium splendens (Hedw.) Br. Eur. At four sampling sites moss was exposed in net bags. The elemental composition of the moss was determined by XRF and ICP-MS. Air filters were analysed by LA -ICP- MS and SEM EDX. We concluded that selected moss species have a different element enrichment capacity. The concentrations of accumulated elements varied between different moss species, seasons and sampling sites. An accumulation of elements from the continental crust was found. In the middle of the Soča valley the accumulation of mercury and thallium was higher than on the slope of the neighbouring valley. Asbestos-like particles were found at all sampling sites.