Chemical characterization of a municipal landfill and its influence on thesurrounding estuarine system, south central Chile.

The spatial and temporal variations of cyclic organochlorine compounds, hea vy metals, total hydrocarbons, surfactants, oil and grease, BOD, (biochemic al oxygen demand), dissolved oxygen and nutrients were measured during summ er and winter of 1996 from the Valdivia municipal landfill and its surround ing estuarine system. During summer it was found that solid and liquid samp les usually contained higher average contents for most of chemical paramete rs than winter samples, with the exception of oil and grease and Pb from le achate samples. Generally, samples from the landfill showed higher levels o f chemical parameters than samples from the Futa River. High levels of hept achlor (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, res pectively) were observed in sediments from a maximum depository zone of a s mall 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 spec ies, 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 hept achlor epoxide were observed in Mytilus chilensis (mussels).