Trace Element Emissions from some Cement Plants in Turkey

The cement industry has been one of the major sources of air pollution in the past and the Turkish Air Quality Protection Regulation has issued limits also to trace elementemissions to minimise the polluting effects of this industrialsector. In the present study, dust samples were obtained isokinetically from 18 main stacks of 10 cement plants locatedin different geographical areas of Turkey. The samples were analysed for trace elements Hg, Cd, Cr, Pb, Ni, Se, Te, TI, V, Sb, Ba, Zn, Co, Sr, Cu, Bi, Mo, Be, and As. The results are presented both as concentration in the dust samples as well as emissions per unit production, and concentration inthe stack gas. The trace element emissions of the main stacksagree to great extent with the values given in the literature. On the other hand, the trace element emissions of the plants considered are well below the limits set in the Turkish Air Quality Protection Regulation.     

Effects of sodium selenite on some biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) exposed to Pb2+ and Cu2+

This study was carried out to understand the preventive effect of selenium (Se⁴⁺) on heavy metal stress induced by lead and copper in rainbow trout (Oncorhynchus mykiss). Variation in glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activity, and in malondialdehyde (MDA) levels in liver, spleen, heart, and brain tissues of rainbow trout after 72 h of exposure to Pb²⁺ and Cu²⁺ were investigated in the presence and absence of Se⁴⁺. In the presence of Se⁴⁺, Se-GSH-Px activity and SOD activity were found to be higher and MDA levels were lower compared with in its absence. Hematological parameters were also determined and it has been observed that total leukocyte count (WBC), mean cell volume (MCV), and mean cell hemoglobin (MCH) were increased and erythrocyte number (RBC), hemoglobin (Hb), and hematocrit value (Hct; P < 0.05) were decreased in fish exposed to heavy metals in the absence of selenium. Selenium presence recovered hematological parameters to normal levels. In the light of our findings, it could be stated that Pb²⁺ and Cu²⁺ lead to dramatic changes in biochemical and hematological parameters and selenium caused these parameters to converge to control levels when it was administered concurrently with these heavy metals.     

Characterization of Cement Plant Emissions in Turkey

In cement plants in Turkey CO, NO₂, SO₂ and particulate emissions were measured using standard measurement techniques and equipment. Emission factors are calculated by dividing the emission rates by capacity of production at the time of measurements for each plant. The results of this study show that the dominant emissions from cement production in Turkey is CO followed by NO₂, dust and SO₂ in decreasing order. National averages for the emission factors are calculated and compared to international emission factors. On average the Turkish dust emission factor is higher than the German factor, however NO₂ and SO₂ emission factors are lower in Turkey.     

Emission Factors of Cement Industry in Turkey

The levels of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S,Se and Zn in the terrestrial mosses Scleropodium purumand Hypnum cupressiforme, collected from 75 samplingsites in Galicia (NW Spain), were determined. Using thesedata, four statistical methods of estimating backgroundlevels were then compared: one based on the use ofmultifactorial analysis, another that uses modal analysis, athird based on analysis of cumulative frequency curves, andthe last, which involves identifying groups of data with acovariance close to 60%. The first method was discountedbecause of difficulties in interpretation of the resultingdata. Very different estimates of background levels ofelements were obtained depending on which of the remainingmethods was used, and modal analysis was finally chosen asthe most suitable. Background levels varied depending on themoss species used and the levels of Al, Cu, Fe, Hg, Mn, Ni,Pb and Se in the two species were significantly different(p < 0.001). It was found that the dominant lithology in thesampling area had no influence on the estimated background levels.     

Antioxidative role of selenium against the toxic effect of heavy metals (Cd<Superscript>+2</Superscript>, Cr<Superscript>+3</Superscript>) on liver of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis> Walbaum 1792)

The main purpose of this study is to discuss the effect of Cd⁺², Cr⁺³ and Se metals on biochemical parameters in liver tissue of Oncorhynchus mykiss. The rainbow trout were exposed to heavy metal stress (Cd⁺², Cr⁺³) at 2 ppm dosage. The present study was undertaken to determine the protective effect of selenium treatment at the same dosage (2 ppm) on some biochemical parameters. The activity of catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and the changes in levels of malondialdehyde (MDA) from biochemical parameters were determined in liver tissue of the fish groups exposed to heavy metals, especially for the selenium-applied groups. Results of this study showed that the activities of CAT, GSH-Px and SOD in the tissues of fish exposed to the stress of Cd⁺² and Cr⁺³ were significantly lower than the control groups (P < 0.05). Meanwhile, the closer values to the control groups were obtained in selenium-added groups (Cr⁺³ + Se⁺⁴, Cd⁺² + Se⁺⁴). For the level of MDA, the last production of lipid peroxidation showed increases (P < 0.05) in the groups exposed to the metal stress, whereas significant decreases were obtained in selenium-applied groups. The result of the statistical evaluation showed that the negative effects occurring in the biochemical parameters of the applied groups exposed to the toxicity of heavy metal were significantly eliminated (P < 0.05) as a result of selenium treatment.