Abstract
A system, based on annular gold-coated denuders, was optimized
and used in the atmospheric sampling of mercury in urban and rural sites of
the Alta Floresta, a region in the Brazilian Amazon. Results showed that vapour
phase mercury (Hgv) is dominant in samples collected
in both sites. However, particulate mercury (Hg) may sometimes be
significant at the urban site, with values representing up to 77% of
the total Hg collected during sampling, but may also be insignificant at the
same site, depending on the gold commercialization activity and, probably,
on the meteorological conditions during the sampling period. The presence
of mercury in both the vapour and particulate phases in the atmosphere of
the urban site can explain the high mercury concentrations found in urban
dust reported for some cities in the Amazon, and also the relatively high
Hg concentrations found in soils adjacent to the urban centre of Alta Floresta.
It appears that the urban dust of “garimpo” areas in the Amazon
can act as an efficient adsorber of Hgv emitted by gold dealer
operations during the