DOI : 10. 1051/jp4 : 20030327 The concentration of some metals (Pb, Cd, Zn and Cu) and delta aminolevulinic acid dehydratase activity of fruit fly (Drosophila melanogaster) living near lead and zinc smelter " Trepça " in Kosova I. R. Elezaj, K. Rr. Letaj, Q. I. Selimi and F. Zhushi-Etemi Department of Biology, University of Prishtina, 38000 Prishtina, Kosova Abstract The concentration of Pb, Cd, Zn and Cu, o-aminolevulinic acid dehydratase activity (ALA-D : EC. 4. 2. 1.24) hemoglobin and protein amount have been determined in three different populations of fruit fly (Drosophila melanogaster) caught at two urban sites (Mitrovica town, which is situated close to smelter of " Trepça " don close and Prishtina the capital of Kosova) and in Luki village as uncontaminated area. The results show that in the fruit fly of Mitrovica the concentration of Pb, Cd and Zn was significantly higher (P<O. OOl) in comparison with that on the f-Liit fly of Prishtina and Luki. The concentration of Pb of fruit fly from Mitrovica was 3. 1 times higher in comparison with that on fruit fly of Prishtina and 4. 9 times higher in comparison with uncontaminated group of fruit fly. The ALA-D activity was significantly inhibited in the homogenate of fruit fly from Mitrovica in comparison with Prishtina and Luki localities (P<0. 001). ALA-D activity was also inhibited in the homogenate of Prishtina fruit fly in comparison with Luki group (P<0. 001). The amount of proteins was significantly lower in Mitrovica fruit fly in comparison with that in control and Prishtina group. The hemoglobin value was relatively unchanged. 1. Introduction The exposure of human populations to heavy metals caused major toxicological problems. Terrestrial organisms primarily take up metals from the food they ingest. Plants can be the source if the insect feeds on plant that has taken up metal from the surroundings. However not all the metal that an organism is exposed to is taken up by the animal. Only the metals present in a bioavailable form such as free iron form, or in metal complexes are taken up [1]. The metals that we are going to present in this paper are essential metals such as copper and zinc (used in enzymatic function ; zinc in some insects is used to harden mouth parts). Nonessential metals such as lead and cadmium will be also considered as metals that can accumulated in insects [1]. The idea of using the insects, as biomonitors can be very useful. They are small active, fast growing animals that are abundant in number, occupy many different environments and are known to accumulate metals. Insects accumulate metals in the fonn of metal-containing granules, which appear to enable the insect to tolerate exposure to metals. However, research is stili needed to gain a complete understanding of the mechanisms of metal uptake, metai tolerance and storage.