“With few exceptions,” said the report, “investigations of leukemia clusters have failed to demonstrate significant associations or even promising leads as to environmental causes.… None of the chemicals found in Wells G and H are known to be leukemogenic, although trichloroethylene and tetrachloroethylene have been found to cause tumors in laboratory animals. The source of the present contaminants is unknown.”

Jonathan Harr, A Civil Action, loc. 285