Accumulation of heavy metals and sulphur in vegetables from allotment gardens of Plock [Central Poland]

During the years 1984-1990, red beet, carrot and parsley were cultivated in four selected allotment gardens situated near the Płock Petrochemical Works (central Poland). Leaves and roots were harvested, dried and analysed for nine heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) and two forms of sulphur (total and sulphate). The accumulation of the heavy metals (except copper) was much higher in vegetable leaves than in the roots. This was especially true for manganese, iron, lead and chromium. Only two metals, cobalt and copper, were gathered in normal concentrations in all samples. Iron, chromium and cadmium were accumulated in above-normal amounts in all analysed vegetable organs. Overall, the contents of iron, chromium, zinc and nickel found in the examined vegetables were harmful for them. Total sulphur and sulphate sulphur showed highest levels in carrot leaves. In this organ both forms of sulphur occurred in amounts which were harmful to the plants. In general, the quality of examined vegetables, considering the accumulation of heavy metals and sulphur, was low because of very high levels of iron and chromium.