The Uptake and Detoxification of C14-labelled DDT in Atlantic Salmon, Salmo salar

Abstract

Atlantic salmon underyearlings were exposed to 1 ppm DDT-C14 and the amounts of DDT adsorbed to external surfaces and absorbed internally determined separately on the basis of the C14 activity. Fish killed by the exposure contained on the average 5.87 ppm DDT of which almost two-thirds represented absorbed DDT. After only 5 minutes exposure appreciable quantities of DDT were found throughout the body. At all times, up to and including the time to death, high concentrations of DDT were found in the gills, liver, spleen, heart, kidneys, gonads, and swim bladder. Much smaller concentrations occurred in the stomach, intestines, brain and spinal cord. The muscles, bone, and integument contained the least. It was concluded that DDT entered mainly through the gills from whence it was transported throughout the body via bone circulatory system.Bioassays showed that on the average almost two-thirds of the absorbed DDT was non-toxic, or at least relatively so, to mosquito larvae. The adsorbed DDT showed little, if any, loss of toxicity.