In case a suspicion of herd contamination occurs, models may only be useful in order to estimate adequate depuration period, if the initial POP body level is known. Therefore, direct in vivo measurements of PCDD/Fs contamination levels will still be required for normative and regulatory purposes. Up-to-date the only available option for quantifying in vivo the body internal POP concentration is to make a biopsy of subcutaneous adipose tissue follow by a target analysis of the POP of interest. Such technic require specific skills, the assistance of a veterinary, and is quite invasive and costly. To overpass such limitations, the development of in vivo proxies of the POP contamination level is required. For the target analysis of lipophilic POPs, a lipid-rich matrix alternative to adipose tissues should be collected. Sampling of cerumen (ear wax) or lanoline (wool grease) seems to be promising options. Preliminary results highlight a parallel accumulation and depuration kinetics in cow milk fat and cerumen PCB concentrations.
Moreover, a reliable estimate of ewe PCBs and TCDD internal contamination status was obtained based on wool grease. Besides, cerumen and lanoline sampling are much less invasive than adipose tissue biopsies. Non-target analyses may also offer innovative proxies of POP contamination status. In such case, the POPs of interest are not directly quantify, but alternative omic and chemometrik technics are combined in order to detect, in animal metabolism, specific fingerprints of POP exposure. Our INRAE partner previously established some proofs
of concept about the reliability of such proxies in poultry or pig. Besides, promising results were recently obtained in the AgroPOP project for lactating cow. Together with being less expensive and less timeconsuming than target analysis, such proxies may be recorded on reduce amount of biological sample, including e.g. cerumen, lanoline, milk or blood. Such omics proxies may also be an option for cheaper and larger scale monitoring plans of meat and offal sanitary safety in slaughterhouses.
