GEO Brasil - UNEP

Figure 3 - Impact of gold prospection in the T apajós River
Aggregates for the Building
Industry – the number of illegal
businesses related to this activity is
considerable and worrisome Due to
marketing factors, these minerals have
to be produced in places close to
consumer centres Thus, this activity
is typical of urban and metropolitan
areas The environmental impact of this
activity is large and uncontrolled,
causing the degradation of delicate
ecological environments, such as
dunes and mangroves, modifying
natural river channels and landscape
features In general, the ditches that
result from this activity are used for
the disposal of building industry waste
or even as landfill (BRAZIL 1998)
Gold and other Precious Minerals
Prospecting – As production and
marketing activities relating to
prospecting tend to be of an informal
nature, where legal, tax and labour
obligations are avoided, the Brazilian
government handles them in a distinct
manner Prospecting is rather regarded
as a social issue, thus a separate matter
from legally organised mining
Sedimentary plume
Native Forest
Clean water
Active prospecting
Degraded area
Sediments in suspention = SS
SS = 540mg/l water
Hg in SS = 42mg/l water
Hg carried = 4t/year
Pollution plume
More sediment
added
SS = 30mg/l water
HginS=6,6mg/lwater
Sedimentary plume
comprises half of the water
of the river
Tapajós River Basin
Amazônia - Brazil
Source: Projeto de Cooperação para
o Desenvolvimento Sustentável no
Setor Mineral - GSC/CPRM/CIDA
LANDSAT = TM3,G = TM4,B = TM5
Kevin Telmer, Maycira Costa, 1998
the state of the environment in Brazil
The environmental impacts of
prospecting are common to all areas
submitted to this type of rudimentary
and predatory extraction activity
Contamination of water resources is
the main one As an example we can
take the work of Telmer et al (1999) in
the auriferous province of Tapajós, in
Para (figure 2, area 13), where the
volume of sediments in suspension in
the Crepori River estuary (extensive
ditches in tributaries, riverside and
riverbed), carries approximately four
tons of mercury The polluting plume
also travels a minimum distance of
30km down the Tapajós River (Figure
3 - image)
In Brazil there are several areas, located
in the states of Minas Gerais and Bahia,
where prospecting is a long-established
activity (Figure 2) Recently, with the
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