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Joshua O. Ojo Oyedele O. Oketayo Charles A. Adesanmi Milena Horvat Darja Mazej Janja Tratnik 《Environmental science and pollution research international》2014,21(2):1124-1132
Blood levels of the elements Cu, Zn, Se, As, Cd, Hg, and Pb have been determined in 62 Nigerian women who were occupationally exposed to vehicular pollution. Mercury was determined using a direct mercury analyzer, while all the other elements were determined by an inductively coupled plasma mass spectrometer system. The mean values for all the toxic elements were all within the recommended desirable/tolerable limits, except for Se (0.44 μg/mL, compared with <0.2 μg/mL recommended by the WHO). More than 98 % of the subjects had blood selenium levels higher than this recommended limit. For As, Hg, and Pb, the corresponding figures of subjects with blood levels above the recommended limits were 4, 8, and 19.3 %, respectively. When the subjects were grouped according to their body mass indexes as normal, underweight, overweight, and obese, analysis of variance shows that mean blood levels of Cu, As, and, to some extent Hg were significantly different in the four nutritional status groups. Blood Hg level correlates significantly with blood As in all the groups, except in obese subjects. Also, a significant correlation between age and blood Hg was observed only in normal subjects and between age and blood Pb only in obese subjects. These results suggest that nutritional status could influence both elemental levels and the interactions between trace elements in the blood of female subjects. Nutrition is therefore a factor to consider in efforts to modify human susceptibility to toxic elements. 相似文献
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Solyanikova IP Travkin VM Rybkina DO Plotnikova EG Golovleva LA 《Journal of environmental science and health. Part. B》2008,43(3):241-252
The present review describes some aspects of organization of biodegradative pathways of Nocardioform microorganisms, first of all, with respect to their ability to degrade aromatic compounds, mostly methylbenzoate, chlorosubstituted phenols, and chlorinated biphenyls and the intermediates of their transformation: 4-chlorobenzoate and para-hydroxybenzoate. Various enzyme systems induced during degradation processes are defined. The ability of microorganisms to induce a few key enzymes under the influence of xenobiotics is described. This ability may increase the biodegradative potential of strains allowing them to survive in the changing environment or demonstrate to some extent the unspecific response of microorganisms to the effect of toxicants. Nocardioform microorganisms responsible for degradation of such persistent compounds as polychlorinated biphenyls, polyaromatic hydrocarbons, chlorinated benzoates and phenols and other xenobiotics are characterized. The possibility of using Nocardioform microorganisms in some aspects of biotechnology due to their ability to produce some compounds important for industry is also estimated. 相似文献
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Al Sayegh Petkovšek S Mazej Grudnik Z Pokorny B 《Environmental monitoring and assessment》2012,184(5):2647-2662
The study, which measured the concentrations of Hg, Pb, Cd, Zn and As in various fish tissues (muscle, gill and liver) of
10 fish species (Abramis brama danubii, Alburnus alburnus alburnus, Barbus meridionalis petenyi, Carassius auratius gibelio, Cyprinus carpio, Lepomis gibossus, Leuciscius cephalus cephalus, Perca fluviatilis fluviatilis, Rutilus rutilus, Scardinus erythrophtlalmus erythrophtlalmus) collected in the Šalek lakes, is the first survey regarding metal concentrations in fish species with samples originating
from Slovene lakes, while only a limited number of such studies have been carried out in southeastern Europe. Since these
lakes are situated in the close vicinity of the largest Slovene thermal power plant, the study provides an insight into the
potential impact of increased levels of metals in the environment as well as an estimate of the contamination of fish tissues
with metals. Furthermore, it was possible to compare the results obtained with those from other studies regarding metal levels
in freshwater fish species. The mean metal concentrations of different tissues irrespective of species varied in the following
ranges: Zn 4.31–199 mg/kg ww, Pb 0.01–0.48 mg/kg ww, As 0.02–0.44 mg/kg ww, Hg <0.01–0.31 mg/kg ww, Cd < 0.01–0.19 mg/kg ww.
In general, higher contents of Hg were found in muscles and livers than in gills and higher contents of As in gills and livers
than in muscles, respectively. The accumulation of Pb and Zn was most pronounced in gills. The result obtained regarding metal
concentrations in fish revealed that the ecosystems of the Šalek lakes are not polluted with Hg and Pb, slightly loaded with
As and Cd and moderately polluted with Zn. In addition, the potential human health risk due to fish consumption was assessed.
This showed that the estimated weekly intakes for all metals were far below provisional permissible tolerable weekly intakes
determined by WHO/FAO. The consumption of fish from the Šalek lakes, therefore, does not pose a risk to human health. 相似文献
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Vivien W. Forner Djurre Holtrop Edwin J. Boezeman Gavin R. Slemp Magdalena Kotek Darja Kragt Mina Askovic Anya Johnson 《组织行为杂志》2024,45(3):434-458
Volunteers represent a global workforce equivalent to 61 million full-time workers. A significant decline in volunteering has highlighted the urgency to better understand and address turnover amongst volunteers. To address this, we conducted a systematic review and meta-analysis of turnover amongst volunteers. We also examined whether staying or leaving has different predictors. The meta-analysis integrated and synthesized 117 studies, encompassing 1104 effect sizes across 55 335 volunteer workers, to identify and quantify relationships between turnover and the broad range of variables that have been examined in the volunteer work domain. Amongst the strongest predictors of volunteer turnover were attitudinal variables, in particular, job satisfaction (ρ = −.58), affective commitment (ρ = −.58), engagement (ρ = −.54) and organizational commitment (ρ = −.54). Contextual variables that showed the largest effects included communication (ρ = .62), organizational support (ρ = −.61) and the quality of the relationship between volunteers and their leader (leader-member exchange, ρ = −.55). We synthesize our findings into an integrative framework delineating the predictors of volunteer turnover. In doing so, we extend turnover research to consider non-remunerated work contexts and provide a basis for developing turnover theory that is responsive to the unique experience of volunteers. 相似文献
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Darja B. ?arkovi? Vladana N. Rajakovi?-Ognjanovi? Ljubinka V. Rajakovi? 《Resources, Conservation and Recycling》2011,55(12):1139-1145
This paper analyses the utilization of water and recycled fiber from waste paper for the production in one Serbian cardboard mill. Water and fiber consumption, wastewater generation and its characteristics, as well as sludge recirculation were monitored during production of various paper types, with different grade and weight. The aim was to evaluate production rationality and running stability concerning water and fiber utilization and possibilities for their conservation. Cleaner production measures inside the mill and in the effluent treatment plant were suggested for the improvement of wastewater quality and water conservation. Savings in water and fibers were estimated, with the respect to economic and environmental aspects of proposed cleaner production measures. 相似文献
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Darja B. Žarković Žaklina N. Todorović Ljubinka V. Rajaković 《Journal of Cleaner Production》2011,19(6-7):764-774
In this study, the performance and the efficiency of physico-chemical effluent treatment in a paper mill was investigated, with the aim of evaluating the treatment rationality and running stability. The effluent treatment plant (ETP) uses alum as a coagulant and polyacrylamide as a flocculant in multi-stage water purification. Inadequate efficiency and some operational problems were observed and their occurrences were investigated. Several simple measures inside the mill and some technical measures can prevent or postpone expensive end-of-pipe treatment investments, such as biological treatment. Chemically enhanced primary treatment under optimal operating conditions can be a stand-alone technique for achieving high quality effluent. Furthermore, reductions in wastewater generation in combination with fiber and filler recovery provide environmental benefits as well as significant economic savings in production. The advantages of the cleaner production approach in existing treatment units compared to expensive biological end-of-pipe technologies are obvious. This study demonstrated that the examined mill could easily and cost-effectively change its water system toward strict discharge limits by continuing to use the existing treatment units. 相似文献
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