• Gehalten van dioxinen in boerenkool

      Liem AKD; Theelen RMC; Hoogerbrugge R; de Jong APJM; LOC; TOX; (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 1993-08-31)
      This report describes the results of a study on dioxin levels in samples of curly kale, collected in deposition areas of municipal waste incinerators and a metal reclamation plant as well as in background locations in the Netherlands. From earlier reports on environmental contamination with dioxins it is known that in areas within a few kilometers of waste incinerators, elevated dioxin levels can be found in top soil, grass and a consequence of this, in cow's milk from locally situated dairy farms. Therefore, it was assumed that in the same areas elevated levels can be found in outside growing crops especially curly kale. For these reasons, the first objective was to obtain more insight in levels of the seventeen toxic polychlorodibenzo-p-dioxins and polychlorodibenzofurans in samples of kale collected in suspected and non-suspected areas, whereas the second objective was to produce more data on dioxin levels in kale to enable assessments of the additional intake of dioxins by the Dutch population by consumption of kale and other leafy vegetables. In February 1991, at the end of the growth period, fourteen samples of kale were collected in deposition areas of two municipal waste incinerators and one metal reclamation plant and two background locations. Strategy in sampling preparation was directed to obtain representative data on dioxin levels in kale for each of the five regions at a limited number of 15-20 samples reserved for this study. Analyses were performed by the use of in-house standard operating procedures for extraction, isolation and GC/MS-analysis of purified extracts. It appeared that no elevated levels chould be found in samples of kale from depostion areas. The dioxin levels of the fourteen samples ranged between 0.52 and 1.3 with a mean of 0.87+-0.06 pg 2,3,7,8-TCDD-equivalents (using International REFs) per g dry weight (pg TEQ/g dry weight). According to consumption data from the Dutch Food Consumption Study 1987-1988, a yearly average of 2 g of kale per person per day is consumed. Using a dioxin level of 1 pg TEQ/g dry weight and an average dry matter content of 15 wt%, and additional daily intake of 0.3 pg TEQ per person can be calculated. When compared to an earlier reported median intake of 70 pg TEQ per person per day by consumption of food products mainly derived from animal fats and oils, a negligible additional intake is obtained by consumption of kale. By extrapolation of these figures to other (leafy) vegetables and fruits, a maximal additional daily intake has been estimated of about 8 pg TEQ per person per day.<br>