Abstract :
Acute lethality tests were conducted using Eisenia fetida exposed to pentachlorophenol (PCP) in artificial soil. Mortalities were monitored intensively over the first 24 h, followed by observations every 48 h for the duration of the 28-day test. Toxicity curves were fitted to data using a one-compartment first-order kinetics model (1CFOK) to determine incipient lethal levels (ILLs). PCP residues were determined by gas chromatography after cryoextraction. The 1CFOK model provided a good fit to the observed data. Critical body residues (CBRs) ranged from 0.33 to 2.65 mmol PCP kg−1 wet wt, even though soil concentrations of PCP ranged over three orders of magnitude. The consistency of CBRs regardless of soil concentrations suggests that they may be a useful tool in assessing the toxicity of soil contaminants to earthworms.
