Uptake and bioconcentration of dieldrin, dimethoate, and permethrin by Tetrahymena pyriformis

A ciliate protozoan, Tetrahymena pyriformis was exposed to three insecticides, dieldrin, dimethoate, and permethrin for 12 hr to study the uptake and bioconcentration potential. Ciliates concentrated 922, 3547, and 1056 mu g g super(-1) dry wt. over an initial concentration of 1 mu g mL super(-1) of dieldrin, dimethoate, and permethrin, respectively. The highest bioconcentration factor for three insecticides was 2095, 3547, and 1110, respectively. It is suggested that if levels in the environment reach 1 mu g mL super(-1) the chief effects would be reduction of cell population, and accumulation of the toxicants by ciliates. Accumulation of insecticides by ciliates would permit the toxicants to enter aquatic food chains. Thus the compounds could exert toxic effects at higher trophic levels.