ESTEROIS COMO INDICADORES DO ACUMULO DE ESGOTOS DOMESTICOS EM SEDIMENTOS DE UM SISTEMA ESTUARINO-LAGUNAR TROPICAL (MUNDAU-MANGUABA, AL)

摘要

The history of sewage contamination in the Mundau-Manguaba estuarine lagoon system (NE Brazilian coastal zone) was evaluated through the concentration of sterols in sediment cores. The concentration of coprostanol increased towards the surface sediments, with the maximum of 5.65 μg g~(-1) at 0-2 cm sediment layer in Mundau. Manguaba exhibited a lower level of contamination. The ratio cholestanol/cholesterol suggested degradation of coprostanol only before the burialof organic matter in the sediment. This feature, together with information of population growth in the watershed, allowed theestimation of a sedimentation rate of 0.90 cm year~(-1) to the Mundau lagoon.