Envix Nord AB

Umeå, Sweden

Envix Nord AB

Umeå, Sweden
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Pradhan A.,Örebro University | Ivarsson P.,Örebro University | Ivarsson P.,BioImpakt AB | Ragnvaldsson D.,Envix Nord AB | And 3 more authors.
Science of the Total Environment | Year: 2017

Metals released into the environment continue to be of concern for human health. However, risk assessment of metal exposure is often based on total metal levels and usually does not take bioavailability data, metal speciation or matrix effects into consideration. The continued development of biological endpoint analyses are therefore of high importance for improved eco-toxicological risk analyses. While there is an on-going debate concerning synergistic or additive effects of low-level mixed exposures there is little environmental data confirming the observations obtained from laboratory experiments. In the present study we utilized qRT-PCR analysis to identify key metal response genes to develop a method for biomonitoring and risk-assessment of metal pollution. The gene expression patterns were determined for juvenile zebrafish exposed to waters from sites down-stream of a closed mining operation. Genes representing different physiological processes including stress response, inflammation, apoptosis, drug metabolism, ion channels and receptors, and genotoxicity were analyzed. The gene expression patterns of zebrafish exposed to laboratory prepared metal mixes were compared to the patterns obtained with fish exposed to the environmental samples with the same metal composition and concentrations. Exposure to environmental samples resulted in fewer alterations in gene expression compared to laboratory mixes. A biotic ligand model (BLM) was used to approximate the bioavailability of the metals in the environmental setting. However, the BLM results were not in agreement with the experimental data, suggesting that the BLM may be overestimating the risk in the environment. The present study therefore supports the inclusion of site-specific biological analyses to complement the present chemical based assays used for environmental risk-assessment. © 2017 Elsevier B.V.

Prikryl R.,Charles University | Torok A.,Budapest University of Technology and Economics | Theodoridou M.,University of Cyprus | Gomez-Heras M.,Complutense University of Madrid | Miskovsky K.,Envix Nord AB
Geological Society Special Publication | Year: 2016

Inorganic raw materials, here termed geomaterials, derived from the Earth's crust and used in construction after appropriate processing make a genetically and functionally varied group of mineral resources. Although their basic functions have remained almost unchanged for centuries, some new attributes, meanings and impacts on society are still emerging. Geomaterials for construction were among the first mineral raw materials exploited, processed and used by man. They helped in the development of technological and artistic skills of humankind. Accessibility, workability and serviceability are considered here as their main functional attributes, being connected with man's skills to find their occurrence, extract and process them, and then use them in the correct way. However, serviceability is a more complex functional attribute as it also encompasses durability of a material in construction. Durability, that is the ability to withstand the action of weathering/decay processes, is an expression of the dynamic interactions between material and the surrounding environment encompassing not only gradual adaptation of materials to current environmental conditions, but also interactions between materials in construction, the history of maintenance/conservation of the structure and the impact of a polluted environment. In the modern world, sustainable use of raw materials, specifically those exploited in the largest volumes such as geomaterials for construction, raises questions of reducing extraction of primary resources and thus minimizing impacts on natural systems, and also employment of materials and technologies to produce less emission of deleterious substances in to the atmosphere. Use of secondary materials such as waste produced during extraction of primary raw materials and/or re-use of existing structural elements and re- or down-cycling can be considered as modern approaches to reducing the pressure on primary resources. © 2016 The Author(s).

Johansson E.,Lulea University of Technology | Johansson E.,Envix Nord AB | Miskovsky K.,Envix Nord AB | Bergknut M.,MTC | Sachlova S.,Charles University
Geological Society Special Publication | Year: 2016

The main petrographic variables of intrusive rocks that influence the technical test methods common used within the aggregate industry were identified and evaluated, the aim being to investigate whether petrographic description could be used as a tool for the preliminary quality evaluation of different rock groups. Evaluation of the dependence of the technical test methods on petrographic variables covered 26 intrusive rocks, including some of their altered varieties (orthogneisses), divided into two groups: 17 granitoids and 9 gabbroids. The selective designated samples were analysed to determine their petrographic characteristics and resistance to fragmentation, wear and wear by abrasion from studded tyres. In order to identify the complicated associations between the petrographic and technical properties, multivariate statistical evaluation was performed. The results of statistical evaluation highlighted that mean grain size of mica minerals, grain size distribution, content of mica minerals and mean grain size were the main variables influencing the technical properties of granitoid rocks, while for gabbroid rocks, the main influences were the frequency of microcracks, mica content, grain size distribution and mean grain size. © 2016 The Author(s).

Saiang C.,Lulea University of Technology | Miskovsky K.,Lulea University of Technology | Miskovsky K.,Envix Nord AB
Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics | Year: 2012

A laboratory study was conducted to study the effect of heat on the mechanical properties of diabase, granite and quartzitic schist at temperatures of 400°C, 750°C and 1100°C. Unheated samples were also studied. The reasoning behind this study was to understand the effect of elevated temperatures on the rock mass, such as in the event of a fire in a rock tunnel. Samples from the aforementioned rock types were heat treated at temperatures shown above, cooled slowly to room temperature and then subjected to uniaxial compression and Brazilian tests. Thin sections were extracted from the heat treated samples for microscopic analyses, which assisted in explaining the reasons for the mechanical behaviour observed from the mechanical test results. The uniaxial compression test showed that the strength of the rock specimens increased by 6% for granite to 29% for diabase at 400°C when compared to the UCS values of the unheated specimens. From 750°C to 1100°C the decay in the strength was very rapid. From the microscopic analyses it was concluded that the increase in the strength of the rock specimens at 400°C is attributed to the initial reaction of the rock forming minerals, hence the rock specimens were less brittle but more plastic. The rapid drop in the strength from 750°C to 1100°C is attributed to the mineralogical changes, micro-cracking and dehydration due to the loss of crystal bound water. At 1100°C the rocks were highly friable and crumbled very easily when tested mechanically. The effect of mineralogical changes was obvious in diabase where the physical appearance of the samples mimicked that of natural iron, which is believed to be due to the alteration of pyroxene. The result was an increase in strength by 29% at 400°C compared to the unheated specimens. Even at 750°C the strength was slightly higher than unheated specimens. In summary; the mechanical behaviour of the rock specimens depended on the temperature level and the mineralogical and physical changes that occur at that temperature. © 2012 Taylor & Francis Group, London.

Kumar R.,Örebro University | Kumar R.,Tomsk State University | Pradhan A.,Örebro University | Khan F.A.,Örebro University | And 4 more authors.
PLoS ONE | Year: 2015

Metals are essential for many physiological processes and are ubiquitously present in the environment. However, high metal concentrations can be harmful to organisms and lead to physiological stress and diseases. The accumulation of transition metals in the environment due to either natural processes or anthropogenic activities such as mining results in the contamination of water and soil environments. The present study used Caenorhabditis elegans to evaluate gene expression as an indicator of physiological response, following exposure to water collected from three different locations downstream of a Swedish mining site and a lab reconstituted metal mixture. Our results indicated that the reconstituted metal mixture exerted a direct stress response in C. elegans whereas the environmental waters elicited either a diminished or abrogated response. This suggests that it is not sufficient to use the biological effects observed from laboratory mixtures to extrapolate the effects observed in complex aquatic environments and apply this to risk assessment and intervention. © 2015 Kumar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Newton S.,University of Stockholm | Bidleman T.,Umeå University | Bergknut M.,Umeå University | Bergknut M.,Envix Nord AB | And 4 more authors.
Environmental Sciences: Processes and Impacts | Year: 2014

Bimonthly bulk atmospheric deposition samples (precipitation + dry particle) were taken for one year at an arctic (Abisko, 68°20′ N, 19°03′ E) and a sub-arctic (Krycklan 64°14′ N, 19°46′ E) location in northern Sweden using Amberlite IRA-743 as an absorbent for hydrophobic pollutants. The samples were analyzed by gas chromatography-high resolution mass spectrometry (GC-HRMS) for polychlorinated biphenyls (PCBs), legacy organochlorine pesticides (OCPs = hexachlorocyclohexanes and chlordane-related compounds), polybrominated diphenyl ethers (PBDEs) and emerging chemicals. Higher deposition rates of most compounds were observed at the more northern site despite its receiving less precipitation and being more remote. HCHs and PCBs made up the bulk of the total deposition at both sites. Five emerging chemicals were detected: the current-use pesticides trifluralin and chlorothalonil; and non-BDE flame retardants 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and Dechlorane Plus (DP). A decrease in the fraction of the anti isomer of DP was observed at the arctic site, indicating isomer-selective degradation or isomerization during long range transport. Air parcel back trajectories revealed a greater influence from air originating over the ocean at the more northern site. The differences in these air sources were reflected in higher ∑HCH to ∑PCB ratios compared to the more southern site, as HCHs are related to volatilization from the ocean and Abisko is located <100 km from the Norwegian coast, while PCBs are emitted from continental sources. This journal is © The Royal Society of Chemistry 2014.

Ragnvaldsson D.,Envix Nord AB | Bergknut M.,Envix Nord AB | Lewis J.,Envix Nord AB | Drotz S.,Metsa Board Sweden AB | And 3 more authors.
Environmental Chemistry Letters | Year: 2014

When exposed to the weather, sulfidic minerals release sulfuric acid, metals and metalloids. This leachate can devastate nearby ecosystems for centuries. This article reports a novel barrier system based on green liquor dregs that reduces acid generation, is inexpensive, and is practical for implementation at operational mines. Two waste rock piles were constructed. One pile was left open to the atmosphere, and the other was sealed with green liquor dregs and partially capped with a polyethylene liner. This test was designed in collaboration with personnel from Boliden Mineral AB, a Swedish mining company in order to ensure that the results would be practical to implement at an operational mine. Leachate flow and chemistry were monitored in both piles over a period of 12 months. Effluent volume was 40 % lower in the test pile, while thirteen of the twenty elements assessed showed average concentrations that were 50 % lower in the test pile than in the control pile. For the most environmentally toxic elements As, Cd, Pb and Hg, reductions were even more significant, ranging between 67 and 87 %. These positive results are hypothesized to be primarily due to the chemical and physical characteristics of the green liquor dregs. The novelty of this result is that it is the first barrier system that fulfills the multiple needs of the Swedish mining industry: It is effective in reducing acid mine drainage while remaining both economical and practical. No other barrier system meets these requirements. © 2014 Springer International Publishing Switzerland.

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