CHEMICAL CHARACTERIZATION OF A MUNICIPAL LANDFILL AND ITS INFLUENCE ON THE SURROUNDING ESTUARINE SYSTEM, SOUTH CENTRAL CHILE
The spatial and temporal variations of cyclic organochlorine compounds, heavy metals, total hydrocarbons, surfactants, oil and grease, BOD5 (biochemical oxygen demand), dissolved oxygen and nutrients were measured during summer and winter of 1996 from the Valdivia municipal landfill and its surrounding estuarine system. During summer it was found that solid and liquid samples usually contained higher average contents for most of chemical parameters than winter samples, with the exception of oil and grease and Pb from leachate samples. Generally, samples from the landfill showed higher levels of chemical parameters than samples from the Futa River. High levels of heptachlor (52.1 ng/g and 31.5 ng/g during summer and winter, respectively) and endosulfan sulphate (127.4 n/g and 11,5 ng/g during summer and winter, respectively) were observed in sediments from a maximum depository zone of a small river adjacent to the landfill which receives the percolated leachates. The temporal variability (summer-winter) showed a significant dilution of pollutants, probably due to rainfall during winter. Estuarine benthos species, Mulinia edulis (clams) and cancer coronatus (crabs) showed low levels for most metals, except Zn in both species, Ni in clams, Cu and As in crabs. Significant levels of total BHC, 4,4 -DDE, aldrin, endrin ketone and heptachlor epoxide were observed in Mytilus chilensis (mussels).