EFFECTS OF PENTACHLOROPHENOL-CONTAMINATED FOOD ORGANISMS ON TOXICITY AND BIOACCUMULATION IN THE FROG XENOPUS-LAEVIS

Sub-adult African clawed frogs (Xenopus laevis) were fed pentachlorophenol (PCP)-injected mealworms containing 64.8 to 2604 ug of PCP per gram of worm for 27 days. There was no mortality and no significant bioaccumulation of PCP in the frogs. After three weeks, frogs fed 2,604 mug/g of PCP ceased eating. The no observed adverse effects level (NOAEL) based on significantly reduced food consumption (PCP-injected mealworms) was 638 mug/g. This corresponded to a NOAEL based on PCP intake of about 8 mug PCP/g frog/day. A toxicity threshold model estimated that about 800 mug/L of waterborne PCP may be a threshold for adverse effects in Xenopus or similar amphibians. Further study is needed to verify threshold estimates.