How are non-cancer health effects evaluated?
EPA evaluates all animal studies of non-cancer health effects to identify the study (critical study) that is most representative of human PCB exposure and that meets rigid scientific criteria. The analysis identified the level where there were no observed adverse effects. Based on the literature, the Agency identified the critical studies for Aroclor 1254 and Aroclor 1016 (presented in tabular form) and described below. Aroclor 1254: The critical study identified was a study of rhesus monkeys conducted by Dr. Arnold and others in 1994. The monkeys were exposed to varying doses of PCBs ingested in gelatin capsules for a period of five years. The critical effects identified were suppression of the immune system, inflammation of the Meibomian gland (a small gland in the inner portion of the eye), and distorted growth of fingernails and toenails. EPA developed a Reference Dose, the level below which adverse effects on the humans are not expected. EPA took the Lowest Observed Adverse Effect
