Combining life-history and toxicokinetic parameters to interpret differences in sensitivity to cadmium between populations of Polycelis tenuis (Platyhelminthes).

Five populations of the planarian Polycelis tenuis, collected from four locations in a metal contaminated stream and from one location in an unpolluted tributary stream, were compared for their sensitivity to cadmium by measuring survival, reproduction, and body size changes during 28 days of exposure via the water. Survival data and bioconcentration of cadmium measured at the end of the experiment enabled the use of a kinetic-based toxicity model, estimating the lethal body concentration, the uptake rate constant, the elimination rate constant, and the ultimate L