A new concept for the bioaccumulation of lead and cadmium along a food chain with farm animals

Abstract

The term bioaccumulation defines the selective accumulation of toxic substances/chemical elements and compounds/ along the food chain. During the period after the 60’s the bioaccumulation of some pesticides was researched. Hebel & Wrigt /1996/ indicate that if the content of DDT in lakes is 1 unit then it reaches 10 million units in predatory fish. This phenomenon, for some unknown reasons, is mechanically transferred to the accumulation of toxic chemical elements. In scientific literature it is admitted that the degree of bioaccumulation of toxic chemical elements is comparable with that of xenobiotics.
In this research we set our aim to study the degree of bioaccumulation of lead and cadmium and to formulate a concept for the bioaccumulation of these elements, which have an increased technogenic klarck in many regions of Bulgaria. The reason we carried out the research in this direction is our first study/together with Krynski/, which indicated that in ecotopes with increased klarck of lead and cadmium, the content of the two toxic elements is
higher in liver and kidneys of rabbits, but the degree of bioaccumulation is considerably lower in comparison with pesticides.