Heavy Metals in Fruit and Berries in Kaunas District (Central Lithuania)

Abstract

During the expeditions of 1989–92, samples of soil, fruit, and berries were picked up in Kaunas District (central Lithuania) and experimental orchards to determine the content of heavy metals (Cr, Pb, Ni, Zn). They were established by the atomic absorption meter AAS-30. Within in the limits of the industrial center (Kaunas), the content of heavy metals in soil exceeds the background: cadmium, 6 times; lead, 3, 6 times; zinc, 5 times. When fruit trees grow within the city limits, chromium and lead accumulates in the fruit skin and pith. There is probability that increased amounts of heavy metals can accumulate in the flesh. Fruit grown by roads with intensive traffic, as in town zones, accumulate chromium in the pith and lead in the skin. Fruit from trees grown at a distance of 50 to 100 m from the road contained high amounts of chromium and lead in the pith. In all investigated cases, nickel and zinc accumulated in the pith. When fruit trees grow by roads with intensive traffic or within city limits, fruit are contaminated more with chromium than with lead. Consumers should use only the flesh and remove the skin and pith of such fruit. In experimental orchards, different crops accumulated different amounts of diverse heavy metals. In an irrigated area, strawberries accumulated more heavy metals than currants. Heavy metals (Cr, Pb, Ni, Zn) were found in small quantities in the flesh of sour cherries and plums. Microfertilizers (0.1% boric acid applied after flowering) reduced the absorption of heavy metals (especially Cr and Pb) to the plant's reproductive organs.