Lead and cadmium contamination of foods and feeds from selected areas of the Erfurt district. 4. Lead in vegetables grown in culture centers of the Erfurt region

Abstract

For the purpose of determining the effect of heavy metal emissions of a great town on the lead and cadmium levels of vegetables that are of relevance to food supply, we analyzed 193 samples of vegetables from the important vegetable-growing centre of Erfurt during a 3-year period. With regard to the main wind direction and the infrastructure of the town, the samples were collected at four different areas under vegetable. Apart from a single exception, the lead and cadmium contents were inferior to the maximum tolerances provided by the regulation concerning the contents of foreign substances in foods, the metal contents of leaf vegetables being higher than those of brassicaceous plants. Vegetable samples from areas with heavier emission burdens showed somewhat higher metal contents. In contrast to this, the cadmium contents did not exhibit such differences. The highest lead and cadmium contents were found in spinach. To elucidate the effect of the washing and blanching techniques used in industrial processing, 23 spinach preserves were analyzed in addition; as expected, the heavy metal contents were reduced by these techniques. In summary, our investigations evidence that the main vegetables cauliflower, white cabbage, red cabbage, savoy cabbage, as well as lettuce and spinach (grown in the district of Erfurt) contribute but little to total food contamination if we consider the amounts consumed on an average.