Organic chemical contaminants in hens egg : regulatory context, modes and risk of transfer

Abstract

The current paper reviews current knowledge on the organic chemical contaminants that may be present in hen eggs. They originateeither from veterinary drugs or feed additives, from pesticides used for cereals production or from persistent pollutants of the environment.Carry-over studies are carried out before veterinary drugs and additives are allowed. For these compounds, official surveysreveal concentrations that are barely over the maximal residues limits. Excessive concentrations may be detected only in cases of inappropriateuse of veterinary drugs or of cross contamination during feed processing, especially for coccidiostats. Carry-over experimentsare also conducted before allowing pesticides to be used for cereal production. Effective control against environmental contaminantsfor animals raised outdoors is not easy. In fact, concentrations of dioxins, furans and polychlorobiphenyls exceeding themaximum concentrations permitted in eggs have been rarely recorded. The worst cases arise in home-produced eggs, probably as aresult of practices that stimulate ingestion of environmental matrices, especially soil. In order to prevent the risk of the presence ofsuch contaminants in eggs, factors affecting soil ingestion in animals raised outdoors should be better understood, and the impact ofsoil on the carry-over of ingested contaminants to eggs should be quantified.