Cow's milk as an indicator of dioxin pollution

Toxicologically important polychlorinated dibenzodioxins and dibenzofurans (PCDD/PCDF), which are substituted at positions 2, 3, 7, 8, accumulate in animal fat and consequently also in cow's milk fat. Milk fat contributes significantly to the population's PCDD/PCDF uptake. The contamination of cow's milk is almost exclusively attributable to PCDD/PCDF intake via fodder. Thus, PCDD/PCDF levels in cow's milk reflect the immission load on fodder production areas. At a farm within the sphere of influence of a copper mill in Tyrol (Austria), cow's milk is continuously being examined as a a means of checking the efficacy of emission-abating measures in the plant. The results show that the contamination of cow's milk decreased from the point when internal measures were taken to abate emissions. As it did not, however, decrease as much as expected, renewed clarification of the immission situation and further measures appear nesessary. The results also offered insights into the behaviour of PCDD/PCDF in the system fodder-cow's milk. (orig.)