EVALUACION DE MATERIA ORGANICA E HIDROCARBUROS AROMATICOS POLICICLICOS EN SEDIMENTOS SUPERFICIALES, BAHIA CONCEPCION-CHILE

analyses for content of total organic matter (tom) and total polynuclear aromatic hydrocarbons (pah) were carried out on surficial benthic sediments from concepcion bay, chile. four potential inputs of pah to this bay include: biological production driven by coastal upwelling processes, submarine outfalls of domestic wastewater, imports from continental river drainage, and release of hydrocarbons during port activities. the objective of the present study was to analyze and postulate sources of the pah in this multiple-use ecosystem. total organic matter was analyzed by ashing of dry samples at 450°c and pah were analyzed by thin layer chromatography followed by analysis of residues using gc-ms. a standard mixture containing 2 to 6 ring aromatics was used for interpreting pah results. results showed relatively high tom content, with low variability among samples (cv < 12%). highest concentrations of aliphatics (rf= 0.94-0.96) and pah (rf = 0.54-0.70) were observed in sediments collected near ports. the pah encountered (presumptively) included anthracene, phenanthrene, fluoranthene, and pyrene, with concentrations below risk levels. analyses of relations between concentrations and distributions suggested that the anthracene originated principally from biogenic precursors, phenanthrene from the oxidation of residual organic matter and wastewater, fluoranthene from hydrocarbon pollution, and pyrene from river drainage from land areas which had experienced forest fires.