Atmospheric aerosol samples from coastal and open ocean environments in
the North Atlantic were analysed for the atmophile elements arsenic and
antimony, and for the marine tracers sodium and magnesium. The aerosol
concentrations of sodium and magnesium were similar in both environments,
about 2000 ng Na (SCM)ˉ¹ and 320 ng Mg (SCM)ˉ¹. The atmophiles were more
concentrated in the coastal aerosol, 0.67 ng As(SCM)ˉ¹ and 0.32 ng Sb (SCM)ˉ¹,
than in the open ocean aerosol, 0.07 ng As (SCM)ˉ¹ and 0.086 ng Sb (SCM)ˉ¹,
and as continental particles were only observed in the coastal aerosol,
this indicates that arsenic and antimony in the marine aerosol are of
continental origin.
Total deposition fluxes to the North Atlantic were about 1.4 kt yrˉ¹for
arsenic and antimony, and about 12 t As yrˉ¹ and 5 t Sb yrˉ¹to the
dissolved phase of the English Channel. Coastal deposition was higher
than the dissolved element fluxes from the River Tamar.
From the above data, steady state models of the arsenic cycle were
developed, and an anthropogenic perturbation rate was calibrated for
kinetic analysis, to define the most sensitive areas of the geochemical
cycle. Air-sea exchange exerts a major control on the atmospheric
transport of pollutant arsenic to the sea, variations in river flow exert
a minor influence. The major unknown factor in the biogeochemistry of
arsenic is the size of the reservoir for low temperature anthropogenic
mobilisation, as this has a larger long term effect than industrial
pollutant input. Low temperature mobilisation may lead to a serious
increase in the atmospheric arsenic burden.
The modelling technique was extended to quantify a novel tentative model
for antimony, which was subject to limited examination by kinetic analysis.
Again, air-sea exchange exerts a major influence on the atmospheric
transport of pollutant antimony to the oceans, although river flow exerts
a larger influence than for arsenic. Low temperature mobilisation may be
even more significant for antimony than for arsenic.School of Environmental Sciences,
University of East Anglia,
Norwich,
East Angli