Equilibrium between uptake and elimination of dieldrin by channel catfish, Ictalurus punctatus

Channel catfish, Ictalurus punctatus, measuring 150 (+/- 5)mm were exposed continuously to dieldrin for 70 days to determine if equilibrium between dieldrin uptake and elimination was reached by muscle tissue. Fish exposed to 13 parts per trillion (pptr) dieldrin reached equilibrium in 56 days, fish exposed to 27 pptr dieldrin were near equilibrium after 56 days, and fish exposed to 49 pptr dieldrin did not reach a balance between uptake and elimination after 70 days of exposure. Evidence of this study showed that balance between uptake and elimination was reached in less time at lower exposure levels than at higher levels.