There is limited evidence regarding the exposure-effect relationship between lung-cancer risk and hexavalent chromium (Cr(VI)) or nickel. We estimated lung-cancer risks in relation to quantitative indices of occupational exposure to Cr(VI) and nickel and their interaction with smoking habits. We pooled 14 case-control studies from Europe and Canada, including 16 901 lung-cancer cases and 20 965 control subjects. A measurement-based job-exposure-matrix estimated job-year-region specific exposure levels to Cr(VI) and nickel, which were linked to the subjects' occupational histories. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated by unconditional logistic regression, adjusting for study, age group, smoking habits and exposure to other occupational lung carcinogens. Due to their high correlation, we refrained from mutually adjusting for Cr(VI) and nickel independently. In men, ORs for the highest quartile of cumulative exposure to CR(VI) were 1.32 (95% CI 1.19-1.47) and 1.29 (95% CI 1.15-1.45) in relation to nickel. Analogous results among women were: 1.04 (95% CI 0.48-2.24) and 1.29 (95% CI 0.60-2.86), respectively. In men, excess lung-cancer risks due to occupational Cr(VI) and nickel exposure were also observed in each stratum of never, former and current smokers. Joint effects of Cr(VI) and nickel with smoking were in general greater than additive, but not different from multiplicative. In summary, relatively low cumulative levels of occupational exposure to Cr(VI) and nickel were associated with increased ORs for lung cancer, particularly in men. However, we cannot rule out a combined classical measurement and Berkson-type of error structure, which may cause differential bias of risk estimates.
- MeSH
- chrom toxicita analýza MeSH
- lidé MeSH
- nádory plic * chemicky indukované epidemiologie MeSH
- nikl toxicita analýza MeSH
- pracovní expozice * škodlivé účinky analýza MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
BACKGROUND: The pan-European human biomonitoring initiative HBM4EU targets the harmonization of human biomonitoring (HBM) procedures and data for both environmental and occupational exposure, including chromium. The determination of chromium in urine (U-Cr), plasma (P-Cr) and whole blood (WB-Cr) is a common HBM application in employees occupationally exposed to chromium (VI) compounds. METHODS: European laboratories which have registered as candidate laboratories for chromium analysis within HBM4EU were invited to participate in a quality assurance/qualitycontrol (QA/QC) programme comprising interlaboratory comparison investigations (ICI) for the parameters U-Cr, P-Cr and WB-Cr. Participating laboratories received two samples of different concentrations in each of four rounds and were asked to analyse the samples using their standard analytical procedure. The data were evaluated by the Z-score approach and were reported to the participants after each round. RESULTS: The majority of the 29 participating laboratories obtained satisfactory results, although low limits of quantification were required to quantify chromium concentrations in some of the ICI materials. The robust relative standard deviation of the participants' results (study RSDR) obtained from all ICI runs ranged from 6 to 16 % for U-Cr, 7-18 % for P-Cr and 4-47 % for WB-Cr. The application of both inductively coupled plasma mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry (EAAS) appeared appropriate for the determination of chromium in urine, plasma and whole blood with regard to occupational exposure levels. CONCLUSION: This QA/QC programme succeeded in establishing a network of laboratories with high analytical comparability and accuracy for the analysis of chromium across Europe.
- MeSH
- biologický monitoring * MeSH
- chrom analýza MeSH
- lidé MeSH
- monitorování životního prostředí MeSH
- pracovní expozice * analýza MeSH
- spektrofotometrie atomová MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
This research deals with the removal of Cr(VI), one of the most toxic heavy metal in biological systems, from wastewater by using activated carbon produced via pyrolysis and chemical activation of "Posidonia oceanica". That is the most important and well-studied seagrass species of the Mediterranean Sea. The as produced activated carbon exhibited high specific surface area up to 1563 m2/g and a cumulative pore volume of 0.74 cm3/g, allocated to 74% micro-pores and 26% to meso-macro- pores. The adsorption capacity of Cr(VI) into Posidonia oceanica activated carbon was studied via batch experiments considering the contact time, the initial concentration and the pH parameters. The results were interpreted using four different adsorption kinetic models. The activated carbon material seems to exhibit excellent sorption properties with rapid removal capability for Cr(VI). The estimated maximum uptake capacity at equilibrium stage was ~120 mg/g. Also, the initial adsorption rate ri was dependent on the initial Cr(VI) concentration in aqueous solution and it was from 77 mg/(g*h) to 264 mg/(g*h). The best fitted kinetic model seems to be the Diffusion-Chemisorption model with the rate constant KDC of the Cr(VI) ions transfer from liquid to solid particles extend from 52 to 78 mg/(g*h0.5).
- MeSH
- adsorpce MeSH
- Alismatales * MeSH
- chemické látky znečišťující vodu * analýza MeSH
- chrom analýza MeSH
- dřevěné a živočišné uhlí MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- pyrolýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Středozemní moře MeSH
Soil pollution with heavy metal is a serious problem across the globe and is on the rise due to the current intensification of chemical industry. The leather industry is one of them, discharging chromium (Cr) in huge quantities during the process of leather tanning and polluting the nearby land and water resources, resulting in deterioration of plant growth. In this study, the effects of biochar application at the rate of 3% were studied on four maize cultivars, namely NK-8441, P-1543, NK-8711, and FH-985, grown in two different tannery polluted Kasur (K) and Sialkot (S) soils. Maize plants were harvested at vegetative growth and results showed that Cr toxicity adversely not only affected their growth, physiology, and biochemistry, but also accumulated in their tissues. However, the level of Cr toxicity, accumulation, and its influence on maize cultivars varied greatly in both soils. In this pot experiment, biochar application played a crucial role in lessening the Cr toxicity level, resulting in significant increase in plant height, biomass (fresh and dry), leaf area, chlorophyll pigments, photosynthesis, and relative water content (RWC) over treatment set as a control. However, applied biochar significantly decreased the electrolyte leakage (EL), antioxidant enzymes, lipid peroxidation, proline content, soluble sugars, and available fraction of Cr in soil as well as Cr (VI and III) concentration in root and shoot tissues of maize plant. In addition to this, maize cultivar differences were also found in relation to their tolerance to Cr toxicity and cultivar P-1543 performed better over other cultivars in both soils. In conclusion, biochar application in tannery polluted soils could be an efficient ecofriendly approach to reduce the Cr toxicity and to promote plant health and growth.
INTRODUCTION: Analysis of the occurrence of cadmium and chromium in selected samples of fruit spirits intended for own consumption. MATERIAL AND METHODS: In our pilot study, we analysed 89 samples of fruit spirits intended for own consumption. The samples were mineralized with use of microwave decomposition system MULTIWAVE 60 50 Hz and analysed by atomic absorption spectrometry with a graphite furnace (AAS GBC XPLORAA 5000 with GF 5000). RESULTS: Most of the analysed samples originated from plums (39), apples (38) and pears (5). The average ethanol concentration was 53.7%. Cadmium and chromium were detected in all samples. The highest concentration of chromium and cadmium was found in the apple spirit (31.9 ± 6.6 μg/l and 40.1 ± 8.3 μg/l). CONCLUSIONS: The ethanol concentration in the samples was higher than in distribution spirits. Concentrations of chromium in all samples did not exceed the limit given by the Slovak legislation or the limit of the AMPHORA. The permissible cadmium concentration (10 μg/l according to the AMPHORA) was exceeded in 9 samples. This indicates the potential importance of cadmium compared to chromium. Due to the lack of information in this field, the study presents an important starting point for further research.
Layered double hydroxide (LDH) is one of the key host phases of Cr(VI) in the natural environment and chromite ore processing residue (COPR), causing serious pollution by Cr(VI). Therefore, efficient extraction or immobilization of the incorporated Cr(VI) in LDH is urgently needed. In this work, simultaneous separation and immobilization of Cr(VI) in LDH by using MgCl2·6H2O under thermal treatment is innovatively proposed. Cr was volatilized as CrCl3 and was immobilized as MgCr2O4 accounted for 62.2% and 37.8%, respectively, under the optimal condition (the mole ratio of Cl/Cr is 9, 700 °C and 120 min). The underlying reaction mechanisms are as follows: (i) HCl produced by MgCl2·6H2O accelerates the destruction of Cr(VI)-LDH layer structure, completely exposing the incorporated Cr(VI), (ii) Cr(VI) is reduced to Cr(III) by Cl-, part of which is directly immobilized as MgCr2O4, and the other part generates CrCl3, which is volatilized or further combined with Mg2+ to form MgCr2O4. The total Cr leaching concentration of the practical COPR sample treated by this method dramatically decreases from 421 to 0.7 mg/L, well below the landfill standard limit (4.5 mg/L). This work provides an attainable strategy for thorough remediation of COPR and inspires the treatment of heavy metal-containing LDH.
This study analysed the effect of three alkalizing soil amendments (limestone, dolomite chalcedonite) on aided phytostabilization with Festuca rubra L. depending on the hexavalent chromium (Cr(VI)) level in contaminated soil. Four different levels of Cr(VI) were added to the soil (0, 50, 100 and 150 mg/kg). The Cr contents in the plant roots and above-ground parts and the soil (total and extracted Cr by 0.01 M CaCl2) were determined with flame atomic absorption spectrometry. The phytotoxicity of the soil was also determined. Soil amended with chalcedonite significantly increased F. rubra biomass. Chalcedonite and limestone favored a considerable accumulation of Cr in the roots. The application of dolomite and limestone to soil contaminated with Cr(VI) contributed to a significant increase in pH values and was found to be the most effective in reducing total Cr and CaCl2-extracted Cr contents from the soil. F. rubra in combination with a chalcedonite amendment appears to be a promising solution for phytostabilization of Cr(VI)-contaminated areas. The use of this model can contribute to reducing human exposure to Cr(VI) and its associated health risks.
The effect of soil amendments, i.e., compost, zeolite, and calcium oxide, on the chemical properties of soil contaminated with Cr(III) and Cr(VI) and the uptake of selected heavy metals by spring barley (Hordeum vulgare L.) and maize (Zea mays L.) was determined in a pot experiment. The content of all investigated heavy metals in the tested plants varied significantly in response to the tested soil amendments and increasing concentrations of Cr(III) and Cr(VI). Compost, zeolite, and calcium oxide contributed to an increase in the average yield of the aerial parts of maize plants only in treatments contaminated with Cr(III). The concentrations of Cr, Zn, and Ni in the aerial parts of spring barley and maize were higher in treatments contaminated with Cr(III) than in treatments contaminated with Cr(VI). Calcium oxide induced a significant increase in soil pH relative to the control treatment. In treatments without soil amendments, the average Cr content of soil was higher in pots contaminated with Cr(VI). The concentrations of Zn and Cu in non-amended treatments were negatively correlated with increasing doses of Cr(III) and Cr(VI). Calcium oxide decreased the average content of Cr, Cu, and Ni in all experimental variants. Compost increased the average content of Zn in treatments contaminated with Cr(III) and Cr(IV) relative to non-amended soil.
The laterite Ni ore smelting operations in Niquelândia and Barro Alto (Goiás State, Brazil) have produced large amounts of fine-grained smelting wastes, which have been stockpiled on dumps and in settling ponds. We investigated granulated slag dusts (n = 5) and fly ash samples (n = 4) with a special focus on their leaching behaviour in deionised water and on the in vitro bioaccessibility in a simulated gastric fluid, to assess the potential exposure risk for humans. Bulk chemical analyses indicated that both wastes contained significant amounts of contaminants: up to 2.6 wt% Ni, 7580 mg/kg Cr, and 508 mg/kg Co. In only one fly ash sample, after 24 h of leaching in deionised water, the concentrations of leached Ni exceeded the limit for hazardous waste according to EU legislation, whereas the other dusts were classified as inert wastes. Bioaccessible fractions (BAF) of the major contaminants (Ni, Co, and Cr) were quite low for the slag dusts and accounted for less than 2 % of total concentrations. In contrast, BAF values were significantly higher for fly ash materials, which reached 13 % for Ni and 19 % for Co. Daily intakes via oral exposure, calculated for an adult (70 kg, dust ingestion rate of 50 mg/day), exceeded neither the tolerable daily intake (TDI) nor the background exposure limits for all of the studied contaminants. Only if a higher ingestion rate is assumed (e.g. 100 mg dust per day for workers in the smelter), the TDI limit for Ni recently defined by European Food Safety Authority (196 µg/day) was exceeded (324 µg/day) for one fly ash sample. Our data indicate that there is only a limited risk to human health related to the ingestion of dust materials generated by laterite Ni ore smelting operations if appropriate safety measures are adopted at the waste disposal sites and within the smelter facility.
- MeSH
- anorganické látky aplikace a dávkování MeSH
- aplikace orální MeSH
- biologické modely MeSH
- chrom analýza MeSH
- hutnictví * MeSH
- kobalt analýza MeSH
- lidé MeSH
- nebezpečný odpad analýza MeSH
- nikl analýza MeSH
- odpadky - odstraňování metody MeSH
- popel uhelný analýza MeSH
- prach analýza MeSH
- průmyslový odpad MeSH
- vystavení vlivu životního prostředí * MeSH
- žaludeční šťáva MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Brazílie MeSH
OBJECTIVES: This study determines the levels of selected contaminants in the muscle of three common fish species from the upper course of the Nitra River. DESIGN: Were detected levels of Zn, Cu, Ni, Cr, Pb, Cd and Hg in the muscle and correlations among selected metals as well as standard length and total weight in brown trout (Salmo trutta morpha fario), Alpine bullhead (Cottus poecilopus) and grayling (Thymallus thymallus). RESULTS: The content of analysed metals (mg.kg-1 wet weight) ranged as follows: brown trout - Zn 5.86-12.97, Cu 0.51-0.76, Ni 0.00-0.37, Cr 0.18-0.41, Pb 0.00-0.34, Cd 0.03-0.13, Hg 0.04-0.07; Alpine bullhead - Zn 7.02-13.68, Cu 0.34-0.62, Ni 0.00-1.13, Cr 0.19-0.24, Pb 0.00-0.37, Cd 0.03-0.09, Hg 0.06-0.18; grayling - Zn 3.38-6.36, Cu - 0.46-0.62, Ni 0.04-0.22, Cr 0.13-0.22, Pb 0.00-0.25, Cd 0.02-0.09, Hg 0.05-0.12, respectively. CONCLUSIONS: The Slovak permissible limits for safe consumption, defined in the Commission Regulations No. 1881/2006 and 629/2008, in the case of Pb, Cd and Hg were exceeded in 10%, 63% and 0%, respectively.
- MeSH
- chrom analýza MeSH
- kadmium analýza MeSH
- měď analýza MeSH
- nikl analýza MeSH
- olovo analýza MeSH
- pstruh MeSH
- řeky * MeSH
- rtuť analýza MeSH
- ryby * MeSH
- Salmonidae MeSH
- svaly chemie MeSH
- těžké kovy analýza MeSH
- zinek analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Slovenská republika MeSH
