Effects of Pentachlorophenol-Contaminated Food Organisms on Toxicity and Bioaccumulation in the Frog 'Xenopus laevis'

摘要

Sub-adult African clawed frogs (Xenopus laevis) were fed pentachlorophenol (PCP)-injected mealworms containing 64.8 to 2,604 mg of PCP per kilogram of worm for 27 days. The objective was to evaluate the effects of PCP-contaminated food organisms on toxicity and bioaccumulation in sub-adult Xenopus laevis and use the data to predict a waterborne PCP concentration that may be a threshold for adverse effects in amphibians. There was no mortality and no significant bioaccumulation of PCP in the frogs. After three weeks, frogs fed 2,604 micrograms/g of PCP ceased eating. The no observed adverse effects level (NOAEL) based on significantly reduced food consumption (PCP-injected mealworms) was 638 micrograms/g. This corresponded to a NOAEL based on PCP intake of about 8 micrograms PCP/g frog/day. A toxicity threshold model estimated that about 800 micrograms/L of waterborne PCP may be a threshold for adverse effects in Xenopus or similar amphibians. Further study is needed to verify threshold estimates.