| Abstract
| - A study was conducted to determine the bioavailability ofseveral pesticides that have persisted for various periodsin soils in the field and the laboratory. Based on theconcentrations or the percentages of the compound insoil samples that were found in the earthworm Eiseniafoetida, ca. 30, 12, 34, and 20% of DDT, DDE, DDD, and a totalof the three compounds were bioavailable in a soiltreated in the field with DDT 49 years earlier. Only 28 or43% of dieldrin aged for 49 years was bioavailable based onconcentrations in E. foetida or percentages of thecompound assimilated by the worms, respectively.Comparably low percentages of DDT, DDE, and DDD butnot dieldrin were assimilated by the worms from samples ofsoil from a waste-disposal site receiving the insecticideca. 30 years earlier. Aging for 190 days in Kendaia loam inthe laboratory markedly reduced the availability to E.foetida of DDT and DDE but not DDD. The amounts of agedor unaged DDT, DDE, and DDD but not dieldrin thatwere removed from the soils by solid-phase extractionwith Tenax TA beads were generally greater with increasingamounts assimilated by the earthworms. The resultsshow that aging markedly reduces the bioavailability ofthese compounds.
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