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(38-67) Human exposure to soil pollution, accumulation of metals in vegetables. Versluijs, Kees*,1, Otte, Piet1, 1 RIVM / LBG pb7, Bilthoven, The Netherlands ABSTRACT- Human exposure to soil pollution, accumulation of metals in vegetables Versluijs CW, Otte PF, RIVM National Institute for Public Health and the Environment, Bilthoven, The Netherlands In the framework of evaluating human exposure to soil pollution, field data on metal accumulation in crops are collected and analysed. The uptake of metals in crops depends on a large range of variables, the most recognizable being type of metal, type of crop, type of soil, concentration level, type of polluting matrix and variations in seasons, farm management and deposition. We collected data restricting ourselves to the collection of field data on the consumed parts of vegetables (and potatoes) popular in the Netherlands, which included soil type characterization (soil pH, percentages of organic carbon and silt). These data were used to identify the crops and soil types with the highest uptake of metals. A Freundlich isotherm-type equation was applied to model - for each couple of metal and crop - the dependency of the bioconcentration factor to soil type parameters and the concentration level in the soil. The influence of other factors was provisionally considered as noise on the data to be averaged out. In the context of this evaluation the sensitivity to the crop type and the concentration level were generally found to dominate. The validity of the relations is analysed with respect to available ranges of the descibing parameters and uncertainties arising. The results were used to calculate: (1) a new proposal for intervention values (in the Netherlands remediation is obligatory on exceeding these values; an average situation with standard soil and a consumption basket are considered here); (2) actual risk estimations (considering specific crop and soil types) and (3) uncertainties in both types of modelling. The issue of quality of compost taken from sites polluted with metals was also tackled. Key words: uptake , metals, vegetables, risk |
