THE TRANSFER OF POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS FROM SOIL INTO EGGS OF FORAGING CHICKEN

The levels of the 2,3,7,8-chlorosubstituted PCDD/Fs (polychlorinated d ibenzo-p-dioxins and dibenzofurans) were determined in eggs of foragin g chicken and in the corresponding soils. Compared to eggs from hens k ept without soil contact the determined levels were clearly elevated. These increased levels were attributed to soil related PCDD/F uptake a nd were used to deduce congener specific factors describing the transf er from soil into the eggs by the foraging. Based on these transfer fa ctors an calculation method allowing the prediction of the 2,3,7,8-TCD D toxic equivalent (I-TEq) levels in eggs based on the PCDD/F concentr ations in soil was developed. The comparison son of predicted and dete rmined PCDD/F levels was used to discuss limitations and uncertainties of the model. Based on a given soil contamination, this approach allo ws a conservative prediction of the I-Teq levels in eggs of foraging c hicken. (C) 1997 Elsevier Science Ltd.