Foram coletados espécimes de mexilhões Perna perna de diversas estações ao longo da costa do Rio de Janeiro e analisados os conteúdos de cobre, zinco, cádmio e cromo. Apesar da grande variabilidade nos organismos pertencentes à mesma população, a avaliação estatística permitiu a diferenciação através de níveis de metal traço entre regiões e estações de coleta assim como entre machos e fêmeas. Diferenças nos conteúdos de metais não confirmam as espectativas baseadas em fontes de contaminação e dados existentes da concentração nas águas.

Perna perna was collected from several sites along the coast of Rio de Janeiro and analysed for the content of copper, zinc, cadmium and chromium. In spite of the observed concentration variability in organisms pertaining to the same population, statistical evaluation allowed metal level differentiation among regions and sites as well as between males and females. Differences in metal contents did not confirm expectations based on source strength and existing data on water concentration.

A critical evaluation is presented on the use of faecal sterols for the identification of sewage contamination in Guanabara Bay. Sediments were collected from 8 stations in the bay selected as representative of different contamination levels. GC/MS determination of faecal sterols gave: coprostanol, 335 - 40000 ng g-1; coprostanone, 112-4136 ng g-1; cholesterol, 1407-7800 ng g-1; cholestanol, 2011 - 10900 ng g-1 and cholestanone, 655-7954 ng g-1. The observed concentration is in accordance with the presence of known pollution sources, however, concentration ratios of different sterols species produced unclear results evidently influenced by primary production and microbial processes.