Particulate matter and element accumulation on coniferous trees at different distances from a highway

Abstract Picea sitchensis (Bong.) Carriere (one- and two-year-old needles) and Pinus sylvestris L. (one-year-old needles), were tested for their capacity to accumulate particulate matter (PM) on the leaf surface or in waxes on the leaf surface. Element accumulation on needle surfaces was also analyzed. Sampling was carried out at four distances from a heavily trafficked road in South Western Norway in October 2012. P. sitchensis accumulated a higher quantity of coarse PM compared to P. sylvestris. Deposition of all fractions of PM increased with time, with largest amounts on two-year-old as compared to one-year-old needles of P. sitchensis . Surface content of 14 out of 25 analyzed elements were highest in P. sitchensis compared to P. sylvestris . A higher accumulation of coarse PM and elements therein (in 14 of 25 elements), was observed in samples taken closest to the road as compared to those from greater distances.