Five Lumbricus terrestris Linneaus were placed into enclosures at a field site and evaluated after 7 d. The enclosures were distributed in transects throughout areas of high and low contamination and in a reference area. Observations of earthworm responses for mortality, morbidity (coiling, stiffening, swelling, lesions) and whole body burden were compared to chemical measurements in corresponding soil samples. Nine chemicals (DDT, DDE, DDD alpha chlordane, gamma-chlordane, chlordene, gamma-chlordene, endrin, nonachlor) were measured in the whole body of earthworms and soil samples. Various levels of impact were described by scoring earthworm responses from sampling locations throughout the field site. A ranking of the sample locations from low to high impact by the earthworm response variables is directly correlated to the ranking of these locations for concentrations of total chlordane and total DDT in corresponding soil samples. Results show acute toxicity to earthworms placed on-site and suggest that whole body concentrations could impact earthworm predators. In addition, the on-site method eliminates the need to transport soils to off-site laboratories, thus preventing subsequent disposal issues. (Copyright (c) 1991 SETAC.)