On the chemical state and mobility of lead and other trace elements at the biogeosphere/technosphere interface

Sammanfattning: Most inorganic contamination has occurred at the interface between the technosphere and the biogeosphere, even though atmospheric emissions have affected the entire globe. Several human activities now pose a substantial threat towards human health and the ecosystems. It was thus decided to study lead as an element with significant anthropogenic emissions in a variety of sources and environments. Lead and other trace elements were studied in groundwaters used for drinking water, in roadside environments, at a shooting range and in a contaminated lake in order to obtain information about mobility and redistribution in different hydrobiogeochemical environments.It was found that 60% of the investigated drilled wells in crystalline bedrock failed to meet international health safety limits. This was mainly due to the presence of enhanced concentrations of fluoride and uranium.Along roads the concentrations and massfluxes increased significantly for lead, as well as for otheer elements during the winter. This is most likely due to increased pavement wear as a consequence of studded tires and use of deicing salts. The mobility of trace elements also increased in the roadside soils, threatening the shallow groundwater.At the shooting range it was found that the downward migration of lead was greater than expected and equilibrium with cerussite was suggested from solid speciation and geochemical calculations. Antimony was associated with lead and showed, despite differences in chemical properties, a similar distribution pattern. This was due to the fact that the major part of the transport at the shooting range was physical.In the contaminated lake, several findings regarding the solid speciation of lead was confirmed and other information about redistribution into the hypolimnion from the sediment was gained.