Abstract

In this report results are given of a study on the occurrence of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in samples of soil and sediment from the Bommelerwaard. From this study the following conclusions have been drawn: 1. In two sediment samples PCDDs and PCDFs levels of 0.06 and 0.43 mug TEQ/kg d.m. have been found. The highest value (0.43 mug TEQ/kg d.m.) exceeds the proposed limit for dioxins in sediments. 2. The level of PCDDs and PCDFs in the two soil samples were 0.06 and 1.11 mug TEQ/kg d.m. respectively. Both levels exceed the proposed limit for grass fields. The high level also exceeded the limits for both residential and agricultural use of land. 3. The patterns of the congener groups of tetra to octachlorinated compounds indicate that the contamination is due to the spilling of pentachlorophenol. 4. At the observed levels of PCDDs and PCDFs in the examined soil samples it can be expected that increased levels of dioxins in the milk fat of cows may occur that exceed the upper limit of 6 pg TEQ/g of milk fat. 5. Further investigation of the distribution and extent of contamination of the soil with PCDDs and PCDFs is recommended. A further analysis of the level of PCDDs and PCDFs in cow's milk from this area is also recommended.