Тяжелые металлы в окружающей среде
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- STUDIES ON HEAVY METALS PRESENCE IN FOOD PRODUCED IN THE AREA AROUND LEAD AND ZINC SMELTER PLANT «ZLETOVO» IN VELES
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0,00 2,00 4,00 6,00 8,00 1 2 Cd (mg/kg) 0,00 100,00 200,00 300,00 1 2 Zn (mg/kg) 0,00 50,00 100,00 150,00 200,00 1 2 Pb (mg/kg) STUDIES ON HEAVY METALS PRESENCE IN FOOD PRODUCED IN THE AREA AROUND LEAD AND ZINC SMELTER PLANT «ZLETOVO» IN VELES The presence of heavy metals in plants is particularly due to its relatively high natural abundance in soil, and partially to contamination by industry (smelters of lead and zinc, production of batteries and dyes) and by traffic (vehicle exhausts).The intensiveand uncontrolled pollution in the past has resulted in the release of large amounts of heavy metals in the local environment, and caused high concentrations of metals to be present in the surrounding soils and water. Vegetables grown in the nearby sites were also contaminated with heavy metals, especially with Cd and Pb, which could be a potential health risk to local in-habitants. In the human body lead is accumulated in the bones, from which it is mobilized when the changes in the organism occur in that case it blockades the work of the enzymes which are taking part in the synthesis of hemoglobinAlso, higher levels of lead in the body can cause disorders as in heart functions, higher blood pressure, influence on central nervous system, etc. Along-term risk assessment needs to be carried out on the leach ability and migration potential of these toxic elements at the contaminated sites. Distribution of heavy metals in some vegetables grown in the vicinity of leadand zinc smelter plant in Veles Gardens near the lead and zinc smelter plant „Zletovo― in the city ofVelesare the main suppliers with vegetables and fruits for the residents in the city. This area was exposed for thirty years to high environmental contamination with heavy metals (Cd, Pb and Zn). As a result of such high values for these elements in soil, their content in the vegetables produced on these gardens was also high. The following study showed contamination with Cd, Pb and Znin washed and unwashed lettuce and carrot grown on contaminated soil.It was found that the content of Cd,Pb and Zn in veg- etables exceeded the maximum permissible concentration. The obtained results from washed andunwashed samples of lettuce and carrot werecompared with the maximum permissible levelac- cording to the Macedonian regulations for foodsafety in fresh vegetables. The limited levelsfor Cd in fresh vegetable for stemmed and rootvegetables is 0.1 mg kg-1 and if we compare theaverage value for Cd from the washed samples ofcarrot (0.32 mg kg-1) it can be seen that the contentof Cd in the edible part of the carrot is 3.2 timeshigher than the permitted levels for Cd in freshvegetable. The unwashed samples for carrot arenot so different from the washed samples (average value of 0.29 mg kg-1). The content of Cd in the washed lettucesamples (0.114 mg kg-1) is less than in un- washedlettuce samples (0.181 mg kg-1), becausedust deposition has an additional influence in the- contamination with these toxic elements. Thus,the permitted levels for Pb in the vegetablesis 0.2 mg kg-1 we can see that in washed samplesof lettuce (0.23 mg kg-1) the content of Pb is in thepermit- ted values but four unwashed lettucesamples (0.49 mg kg-1) is 1.6 times higher. Forthe obtained values for the content of Pb in washedsamples of carrot (1.0 mg kg-1) we can see that thecontent of Pb in the carrot is 10 times higher thanthe permitted levels for Pb in fresh carrot. Thus,for the un- washed samples of carrot (1.33 mg kg-1) the content of Pb is similar as those in washedsamples. The same conclusion could be obtainedfor the content of Zn. Namely, its content in washed(3.16 mg kg-1) and unwashed (3.37 mg kg-1) samplesof carrot and washed lettuce (1.5 mg kg-1) anun- washed lettuce (1.99 mg kg-1) aresimilar (Pančevski et al., 2014; Stafilov et al., 2013). The results of this estimations are presented in Fig. 2. This means that the local inhabitants wereexposed to heavy metal contamination consum- ingvegetables that grow in the Veles area. Cd and Pbare nonessential elements and their presence evenat very low concentration causes adverse healtheffects to human health. The present re- sultsindicate that there is a serious potential healthrisk associated with Cd and Pb in vegetables that- threatens inhabitants in the vicinity of Veles. 120 121 Fig. 2. Presence of Cd, Pb and Zn in vegetable samples (carrot and lettuce) taken from the vicinity of lead-zinc smelter near Veles (black line = permitted level) Occurrence of lead in some beverage products in the vicinity of leadand zinc smelter plant in Veles The aim of the study was to estimate the presence of lead in wines produced around Veles city. From the gained results can be seen that the lead content in the most of the wine samples from'Titov Veles region, occurs in concentration lower than those permitted by Macedonian government (maximum 0.3 mg/dm"). But, in one sample of Srnederevka white wine the content of lead is 0,325 mg'dm" and in other sample of home made red wine, produced from vineyard near lead smehing factory, the concentration of lead is very high -1,03 mgdm", It can be concluded that the lead concentration in wine samples depends from the distance ofvineyard from the lead smelting factory (Stafilov, Jordanovska, 1994). жүктеу/скачать 6.49 Mb. Достарыңызбен бөлісу:
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