Monitoring of PAHs in the natural protected areas in non-heating season using Norway spruce (Picea abies (L.) Karst) needlesJacek Borgulat, Tomasz Staszewski and Włodzimierz ŁukasikE3S Web of Conferences, 28 (2018) 01004DOI: https://doi.org/10.1051/e3sconf/20182801004