[Heavy metal content of cereals and potatoes]

By means of atomic absorption spectrometry, the authors determined the cadmium, zinc, copper and manganese contents in potatoes and cereals from three territories differently burdened by heavy-metal immissions (rural region, overcrowded urban region, region with non-ferrous metal industry). Of these elements, cadmium was most enriched, followed (by a wide margin) by zinc and copper, whereas the manganese level was slightly higher in the burdened region II (compared to the burdened region I) and somewhat lower in the burdened region III. Compared to normal values (0.035--0.080 p.p.m.), i. e., values found in non-burdened regions, the cadmium contents were some 2- to 6-fold higher in air-dry samples of wheat, barley and rye from the burdened regions, some 30-fold higher in oats, and some 3- to 4-fold higher in potatoes (normal values, on a dry-weight basis, (0.140 p.p.m.). As to cereals, the zinc levels were, at the most, some 2-fold higher than the normal values (29--34 p.p.m.), the copper contents were, at the most, some 1.5-fold higher than the normal values (4.1 bis 4.8 p.p.m.), whereas the manganese levels (normal values, 14--30 p.p.m.) were less by half. In potatoes, the zinc contents were but slightly higher than the normal values (18.5 p.p.m., on a dry-weight basis), the copper levels (4.6 p.p.m., on a dry-weight basis) were some 2-fold higher, and the manganese contents (7.2 p.p.m., on a dry-weight basis) were somewhat reduced. On an average 26% (region with non-ferrous metal industry) or 13% (normal region) of the heavy metals are removable from potatoes by washing. On the basis of the results obtained and of data from the literature, an estimate is calculated for the expected values in territories differently burdened by heavy-metal immissions. Finally, targeted suggestions are given for preventing or impeding the entrance of heavy metals into the biocycle.