Epsilon Open Archive

Abstract

The fate and distribution of semivolatile organic pollutants (SOC) and has received much attention during the last decade. The aim of this thesis is to address key issues concerning the fate of some selected pollutants in the terrestrial environment. Specifically, several aspects of the uptake of airborne organic pollutants in pines has been studied. The geographical distribution of some organochlorines in pines was investigated in a transect from Central to Northernmost Europe and also in the former Eastern Europe. Most compounds with a recent active use in Europe showed higher concentrations in the south than in the north. However, the industrial by-product hexachlorobenzene had elevated levels close to industrial centra, and α-hexachlorocyclohexane (α-HCH) had similar concentrations throughout. To properly interpret such data the variability within a forest stand was investigated for selected compounds. The relative standard deviation was found to be better than 25 % for all analytes. The accumulation during the life span of the needles and the seasonal uptake pattern was investigated. A significant uptake during the warm season was found for the most volatile of the analytes, while little happened during winter. This is contrary to what would be expected from physicochemical considerations. It was therefore concluded that there must be a biological factor that alters the properties of the needles so that the accumulation is highest in summer. The least volatile analytes had a transient concentration peak during winter, and analytes with intermediate volatility showed an intermediate behaviour. To test if the terpene concentration in the needles could be the biological factor that explains the uptake pattern of the most volatile compounds, the mono- and sesquiterpene concentrations were measured. It was found that although the total terpene concentration in the needles did not covary with the uptake of α- and γ-HCH, the concentration of terpenes in the soluble cuticular lipids showed peak concentrations during summer, at the same time as the highest uptake of the volatile analytes is expected.