Abstract

Since February 1990, dioxin levels are measured in cow's milk from selected dairy farms in the neighbourhood of dioxin sources like municipal waste incinerators (MWIs) and metal reclamation plants. Levels are expressed in picograms 2,3,7,8-TCDD toxicity equivalents (TEQ) per gram of milk fat, calculated on the basis of international toxicity equivalence factors (I-TEF) of individual congeners. This report presents the results of the measurements in samples of cow's milk from three dairy farms near the MWI of Rotterdam (the Lickebaert area), the Netherlands. These samples were collected in the period of July to September 1993. Dioxin levels ranged between 3.8 +/- 0.2 and 6.2 +/- 0.3 pg TEQ/g of fat. The decline as observed in the period April to June 1993 proceeds less clearly and seems to stabilize at a level between 4.6 +/- 0.2 and 5.1 +/- 0.3 pg TEQ/g of fat in September 1993, just below the Dutch legislation level for dioxins in cow's milk (6 pg TEQ/g of fat).