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(W/EH026) Dioxin-activity in animal fat, TEQ measurements by chemical analyses and by CALUX bioassay . Goyvaerts, Marie Pierre1, Ooms, Daniella1, Van Cleuvenbergen, Rudy1, Schoeters, Greet1, 1 ABSTRACT- Polyhalogenated aromatic hydrocarbons (PHAHs) are known as persistent and lipophylic environmental contaminants. They tend to bioaccumulate throughout the food chain. As a result, food represents the main route of exposure to dioxins for humans and wild life. Monitoring schedules to control the levels of PHAHs have been developed. They are mainly based on chemical measurements of marker PCBs and of dioxins and furans. More recently the Chemical-Activated Luciferase Gene expression bioassay (CALUX) bioassay has been applied on animal fat samples. This CALUX bioassay offers the possibility to screen large numbers of samples in a short time, on a cost-effective basis. The bioassay measures the biological activity of the combination of PHAHs which is extracted from animal fat. Results are expressed as Toxic Equivalence to 2,3,7,8 Tetrachlorobenzodioxin (TEQ-TCDD). Extraction procedures for PHAHs from different animal tissue matrices have been optimised. Detection limits and quantification limits were identified. Reproducibility has been measured. CALUX results were obtained from a diverse set of animal fats: cows milk , cheese samples and chicken eggs. The same samples were chemically analysed for PCBs, PCDDs and PCDFs. TEQ values based on chemical measurements and TEQ values directly measured by the bioassay are compared. The CALUX bioassay may be a valuable tool to evaluate the dioxin-activity also in wild life biomonitoring programs. Key words: dioxin-activity, food matrix, bioassays, TEQ values |
