Modeling Heavy Metals in Europe’s Atmosphere: A Combined Trajectory-Climatologic Approach

Abstract

The long range transport of heavy metals in the atmosphere leads to low but steady deposition of heavy metals into soils, lakes and forests in Europe. Although their atmospheric fluxes are low, these metals can accumulate in the detritus of soils. This accumulated metal may be mobilized by acidification and may then disturb soil organisms, which in turn can lead to disturbance of organic matter decomposition and nutrient cycling (Ottar et al., 1989). Circumstantial evidence from wind sector analysis and trajectory modeling (Pacyna et al., 1984), and receptor modeling (Stevens et al., 1984) indicates that the deposition of metals may originate from sources many hundreds of kilometers away. It is thought that large particles (> 10 μ) settle out in the vicinity of the stacks but stack gases containing metals condense into small particles which then coalesce within hours into particles with diameters of 0.1 to 1.0 μ; particles of this size are too coarse to be efficiently removed by brownian diffusion yet too small to settle out by gravity. Hence these metal particles may travel long distances before being removed by precipitation or dry deposition.