title: Degradation, release and bioavailability of 14C DDT and 14C DDE sediment residues to oysters and mussels.
abstract: Sediment borne pesticides are one of the major routes of transport of pesticides into the aquatic environment and could affect biota living closely in contact with it. Sediment residues of DDT were found to be easily adsorbed (95.0%) and were released in hard water (8.4%) and seawater (0.1%). DDT and DDE sediment residues were released into sterile and nonsterile brackish water indicating minimal role of micro-organisms. DDT was detected in oyster and in mussel with an average of 46-62% in the shell, 19-31% in the tissues and 19-23% in the fluids. Most of the sediment residues were extractable and released residues in water were in the form of DDT. In the presence oysters, bound was transformed into extractable DDT in sediment after 30 days equivalent to 26% of the total concentration. Most biota residues were extractable and an average of 46% was transformed to DDE. Uptake of residues depend on whether the source of contamination was by direct addition to the water or through sediment residues, if food was given or not, if the source of sediment residues were either aged or freshly treated and if residues were extractable or non-extractable.
authors.affiliation: Chemical Control, Pesticide Toxicology and Chemistry Laboratory, National Crop Protection Center, University of the Philippines at Los Baños College, Laguna, Philippines 4031.
authors.forename: C M
authors.initials: CM
authors.lastname: Bajet
authors.forename: M P
authors.initials: MP
authors.lastname: Navarro
mesh_terms: D000327:Adsorption; D000818:Animals; D001682:Biological Availability; D049872:Bivalvia; D002250:Carbon Radioisotopes / Q000032:analysis; D003634:DDT / Q000378:metabolism* / Q000493:pharmacokinetics; D003633:Dichlorodiphenyl Dichloroethylene / Q000378:metabolism* / Q000493:pharmacokinetics; D019015:Geologic Sediments / Q000737:chemistry*; D007306:Insecticides / Q000378:metabolism* / Q000493:pharmacokinetics; D010125:Ostreidae; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000493:pharmacokinetics
chemical_list: D002250:Carbon Radioisotopes; D007306:Insecticides; D014874:Water Pollutants, Chemical; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT