The first group is exclusively composed of samples from the
Farias River and the Canal do Cunha; the second group is composed
of the remaining samples, which are associated with the area west
of Guanabara Bay.
The separation obtained from the two relatively homogenous
groups indicates that these distinct features can be explained by geochemical processes or anthropogenic influences (Carrasco et al.,
2003).
Among the evaluated groups, group 1 is highlighted because the
analyzed points are closer to industrial effluents and are also
located in areas of domestic effluents. In group 2, the similarity
between collection points GN48 and GN50 reflects the proximity
of these points to rejects from contributing rivers in the Canal do
Cunha and a lesser influence from marine currents; therefore, more
environmental degradation exists in these areas of Guanabara Bay.