Chemical and bacteriological evaluation of the water and mussels from Santos bay, São Paulo, Brazil

ABSTRACT

The sea water and Perna perna mussels samples were bimonthly collected from Santos bay from December 2006 to April 2008, and the occurrence of heavy metals, organic compounds and bacteria were investigated. Water and mussel meat quality were assessed following the Brazilian legislation. The analyses on heavy metals mercury, lead, zinc and cadmium contents were performed using atomic absorption spectrometry.The mussel meat was investigated by analytical methodologies following the international recommendations. Among the analyzed sea water samples, at least one sample showed chlorine, phosphorus, sulfide, total fluoride, ammoniac nitrogen, aluminum, lead and iron contents out of the established limits. In one mussel meat sample only a high peak of zinc concentration was found. The bacteriological agents found in water and mussel meat samples were sporadically above the recommended values.

RESUMO

Amostras de água do mar e de mexilhão Perna perna, coletadas bimestralmente da baía de Santos, no período de dezembro de 2006 a abril de 2008, foram analisadas quanto à presença de metais pesados, compostos orgânicos e bactérias. A qualidade da água e da carne de mexilhão foi avaliada seguindo-se a legislação brasileira. As análises dos metais pesados mercúrio, chumbo, zinco e cádmio foram realizadas pela técnica de espectrometria de absorção atômica. As amostras de carne de mexilhão foram analisadas de acordo com as recomendações internacionais. Entre as amostras de água do mar, pelo menos uma apresentou teor de o cloro, fósforo, sulfeto, fluoreto total, nitrogênio amoniacal, alumínio, chumbo e ferro fora dos limites estabelecidos. Apenas uma amostra de carne do mexilhão apresentou pico elevado de concentração de zinco. Os agentes bacteriológicos analisados nas amostras de água e de carne estavam esporadicamente acima dos valores recomendados.