Health Risk of Heavy Metals Related to Consumption of Vegetables in Areas of Industrial Impact in the Republic of Kazakhstan-Case Study for Oskemen.

Among various heavy metal sources the metallurgic industry is the most threatening because emitted metals presented are the chemical forms in which metals are found in soil are more bioavailable and thus very easily are introduced into the environment and spread in both soils and plants. In this study such a situation is presented and the potential negative effect of emitted metals on soil and vegetables is estimated. Therefore, the following indicators were used: bioconcentration factors calculated for the total amount of metals (BCF) as well as daily intake of metal (DIM) and health risk index (HRI). Analyzed soils and vegetables originated from allotment gardens located at different distances from local industrial plants. The greatest amounts of metals in investigated materials (soils and plants) were found for the industrial zone and the lowest for samples representing the suburban zone. Among the analyzed metals Zn showed the highest (223.94−2645.13 mg·kg−1 for soils and 9.14−49.28 mg·kg−1 for plants), and Cd the lowest levels (1.77−15.2 mg·kg−1 for soils and 0.05−0.46 mg·kg−1 for plants). Regardless of the metal, the lowest BCF values were calculated for plants from the industrial zone and the highest from the urban site. Generally, BCF values calculated for vegetables were low and comparable for carrots, tomatoes, and cabbage. BCF values obtained for beetroots were higher in comparison to other vegetables. Regardless of plants, DIM values for Cd and Pb were low and comparable. DIM values for Cu and Zn were higher, but simultaneously strongly differentiated depending on the analyzed vegetables. A similar tendency was found in the case of HRI. The highest values were recorded for Cu and Zn in tomatoes. Regardless of the individual metals, the calculated values for DIM and HRI indices increased in the following sequence: beetroot < cabbage < carrot < tomato. The Zn and Cu contents in the studied types of vegetables do not exceed the maximum permissible levels recommended by WHO/FAO. In contrast, Pb concentrations were higher than the imposed standards in all the analyzed vegetable samples. On the basis of obtained DIM and HRI indices, consumption of vegetables cultivated in industrial areas should be restricted due to health risks related to heavy metals contained in plants.

Trace metal (Cd, Cu, Pb, Zn) fractionation in urban-industrial soils of Ust-Kamenogorsk (Oskemen), Kazakhstan-implications for the assessment of environmental quality.

Ust-Kamenogorsk is one of the largest cities and industrial centers in Kazakhstan. Non-ferrous metallurgy (Zn-Pb smelter) has acted as a predominating industrial branch in the city since late 1940s. The industrial plants are situated directly adjacent to the residential area of the city which creates grievous ecotoxicological hazard. In the present paper, we aimed at assessing the trace metal pollution of top soils in Ust-Kamenogorsk and its potential threats to the local population. The top soils were sampled at 10 sites throughout the city center. We determined the physical and chemical properties of soils as well as the contents of Cd, Cu, Pb, and Zn. In addition, the soil samples were subjected to a five-step sequential extraction to ascertain the fractionation of trace metals. On this basis, we calculated the geoaccumulation index (Igeo) and pollution load index (PLI) and assessed bioavailability of the elements. From our data, it emerged that the soils displayed a strong polymetallic pollution. PLI was as high as 33.4. Throughout the city, the trace metal contents exceeded the geochemical background and allowable values for residential, recreational, and institutional areas. The Igeo obtained were 3.7-6.5 for Cd, 1.5-4.7 for Cu, 2.8-5.7 for Pb, and 2.6-4.6 for Zn. The soils in Ust-Kamenogorsk displayed extremely high contamination with Cd, moderate to strong contamination with Pb and Zn, and low to moderate contamination with Cu. Cd and Pb were found to be the most bioavailable elements. The mobility of trace metals in the soils changed in the order Cd > Pb > Zn > Cu.

Assessment of potentially reactive pools of aluminium in poor forest soils using two methods of fractionation analysis.

The research was carried out in a pine-covered area of the Wielkopolski National Park (Poland), for years exposed to acid rain. The soils under study are sands and loamy sands with a pH of 3.3-4.4. To assess potentially reactive pools of aluminium in those soils, two methods were employed: sequential and single extraction. For the exchangeable form the results obtained by single extraction using KCl greatly exceeded the figures yielded by sequential extraction, in which the conditions under which the process was executed (pH 7) led to an underestimation of the results. The soil profile displayed a lithogenically dichotomous structure which was reflected in the aluminium content, especially in Al extracted by pyrophosphate (single extraction) and in the so-called oxidisable fraction (sequential extraction). In both cases there was a jump in Al concentrations resulted from the release of aluminium from interlayer spaces of clay minerals. The labile percentage obtained for mean values in the profile amounted from 8.1% for single extraction to 12.1% for sequential extraction, which may indicate the metal's considerable pool of potentially reactive aluminium. Single extraction seems to be more reliable in evaluating Al forms.