with a direct and immediate influence on human health (Cowen
and Silver, 1984).Manipulation of the remediation process remains
challenging due to the lack of knowledge on the behavior of metals
in aquatic ecosystems (Warren and Haach, 2001).
According to Warren and Haach (2001), metals can exist in various
forms in water; however, all metals are not equally toxic,
mobile or bioavailable. Metal associations are dynamic, reversible
and reflect physicochemical changes in the water. Consequently,
potential effects from metals released from sediment exist even
with reduced amounts of metals (Fonseca, 2004).
The main factors that cause pollution in the Canal do Cunha
basin include organic components, heavy metals and nutrients,
which originate from domestic sewage and industrial effluents.
Unfortunately, the organic loads that are discharged into the bay
cannot be directly measured. Therefore, such organic rejects are
estimated from the population that contributes to drainage to
the bay and from the economic activities of the region.
The aim of this study was to examine the dynamics of heavy
metals within the Cunha Canal watershed and Guanabara Bay. A
geographic information system (GIS) is employed to evaluate the
distribution of heavy metals in surface water and sediment on
the Cunha Canal watershed and Guanabara Bay. Thematic maps
that characterize the entire region are presented.