Geokemisk undersökning vid Rävlidmyrgruvan, Västerbottens län : provtagning, analys och förslag till åtgärder

The mining industry, in terms of ore excavation and metal production, is and has been important to the Swedish economy. In connection with the ore excavation process, large amounts of partly sulphidic waste are produced. When the metal sulphides are exposed to air and water they are eventually oxidised, which leads to the formation of acidic water with high concentrations of metal cations and sulphate ions, so called Acid Mine Drainage (AMD). This water may reach the nearest surroundings and cause negative environmental effects. By covering the waste with soil or water, the oxidation process can be minimised. At the Rävlidmyran mine in the county of Västerbotten open pit mining took place between 1951 and 1991. When the mining activities ceased the pit was filled with water forming a pit lake. Waste rock dumps, which are partly contaminated with the sulphide mineral pyrite, and covered by till material surround the pit lake. Despite previous remediation measures, there is still a leakage of metal ions to the nearby lake Hornträsket. The lake is presently considered as an oligotrophic lake, which is contaminated with heavy metals. The main purpose of the present study was to investigate possible remediation measures for reducing heavy metal leakage, based on the results of chemical analyses. The specific purposes were: (1) to collect samples within the catchment of the Rävlidmyran mine and to predict how the metal flows take place and to investigate whether sulphate reduction is important or not (2) to collect samples in the pit lake to get a picture of its chemical and biological condition and (3) to contribute to an updating of a semiquantitative heavy metal budget for the lake Hornträsket and quantify the contribution of heavy metals from the Rävlidmyran mine. Water samples collected in the catchment were analysed for pH and electrical conductivity (EC), the total concentrations of Cu, Zn, Cd and Fe, and the concentrations of Cl-, TOC and SO42-. At several sampling points the water flow was measured with a V-notch. Minerogenic and organic sediment samples were also collected and analysed for total concentrations of Cu, Zn, Cd, Fe och As. In the pit lake, water samples were collected at 0-, 2-, 5-, 8 and 12- meter depths. These samples were analysed for pH and EC as well as the total concentrations of Cu, Zn, Cd and Fe plus the concentrations of H2PO4- and SO42-. Some leakage points were identified where the water had an exceptionally low pH and high concentrations of metals and sulphate, probably as a direct cause of pyrite oxidation. This conclusion was partly supported by an analysis of sulphur isotopes. Among the sediment samples the organic sediments had the highest concentrations of Cu, Zn and Cd, while the minerogenic sediments had the highest concentrations of Fe and As. It was concluded that the environment in the pit lake was not optimal for sulphate reducing bacteria (SRB). However, analysis of sulphur isotopes indicated that sulphate reduction might occur in microenvironments of the pit lake. One suggested measure against high acidity is to inject a slurry of reactive lime stone and sewage sludge into the waste rock dump. This should increase the pH and facilitate reducing conditions, which should keep the heavy metals in precipitated metal sulphides. Addition of sewage sludge to the pit lake should favour an increased production of algae. Decomposition of the algae may create reducing conditions that should favour the formation of precipitated metal sulphides.Gruvnäringen, i form av malmbrytning och metallproduktion, är och har varit viktig för den svenska ekonomin. I samband med brytning av malm produceras stora mängder avfall som till stor del är sulfidhaltigt. I kontakt med syre och vatten sker en oxidation av metallsulfiderna i gruvavfallet. En konsekvens av detta är att surt och metallhaltigt lakvatten, (Eng. ’Acid mine drainage (AMD)’) kan nå omgivande terräng och orsaka negativa miljöeffekter. Genom att täcka avfallet med jord eller vatten kan oxidationen minimeras. Vid Rävlidmyrgruvan i Västerbottens län bedrevs mellan 1951 och 1991 gruvbrytning i dagbrott. Gruvan vattenfylldes därpå och en så kallad dagbrottssjö skapades. Dagbrottssjön omges av vallar av moräntäckt sidoberg, som till viss del är förorenat med sulfidmineralet pyrit. Trots åtgärder i dagbrottssjön läcker gruvan metaller till den närbelägna sjön Hornträsket. Idag betraktas den som en näringsfattig och tungmetallförgiftad sjö. Det övergripande syftet med studien var att med ett förbättrat dataunderlag baserat på provtagningar och kemiska analyser utreda vilka åtgärder som behöver vidtas för att minska metalläckage inom avrinningsområdet. De specifika syftena var att: (1) ta prover inom Rävlidmyrgruvans avrinningsområde för att bedöma var de största metallflödena sker samt om det sker en sulfatreduktion; (2) ta vattenprover i dagbrottssjön för att ge underlag för en bedömning av vilka förhållanden som råder i sjön samt (3) med hjälp av framtagna data uppdatera en metallbudget för sjön Hornträsket samt beräkna metalltransporter inom Rävlidmyrgruvans avrinningsområde. Inom avrinningsområdet togs vattenprov som analyserades med avseende på pH, elektrisk konduktivitet (EC), totalkoncentrationerna av Cu, Zn, Cd och Fe samt halterna av Cl- , TOC och SO4 2-. I vissa av provpunkterna mättes vattenflödet med ett V-överfall. Ett antal minerogena och organiska sedimentprov togs som analyserades med avseende på totalkoncentrationerna av Cu, Zn, Cd, Fe och As. I dagbrottssjön togs vattenprover på 0, 2, 5, 8 och 12 meters djup. Proverna analyserades med avseende på pH och EC, totalkoncentrationerna av Cu, Zn, Cd och Fe samt koncentrationerna av H2PO4- och SO42-. Ett antal läckagepunkter med lågt pH och höga metall- och sulfathalter kunde identifieras, vilket troligen var en direkt följd av en pågående sulfidoxidation. Detta kunde delvis bestyrkas av svavelisotopsammansättningen. De organiska sedimentproven hade höga totalhalter av Cu, Zn och Cd, medan de minerogena sedimenten hade höga Fe- och As-halter. Miljön i dagbrottssjön var inte optimal för sulfatreducerande bakterier (SRB). Svavelisotopsammansättningen indikerade dock att det pågick en sulfatreduktion i skyddade mikromiljöer. En åtgärd som föreslogs var att injicera en blandning av mesakalk och avloppsslam i vallen. Detta höjer pH-värdet och skapar på sikt en reducerande miljö, varvid tungmetaller kan fastläggas i utfällda sulfidmineral. Tillförsel av avloppsslam till dagbrottssjön skulle kunna bidra till en ökad algproduktion. Vid nedbrytningen av dessa alger kan reducerande förhållanden skapas, vilket gynnar sulfatreducerande bakterier och sulfidutfällning. Slutligen föreslogs gödsling av de tallar som växer på vallen. Ökad trädtillväxt minskar avrinningen och jorden stabiliseras, vilket minskar erosionen

The impact of type 2 diabetes on long-term gastrointestinal sequelae after colorectal cancer surgery:national population-based study

BACKGROUND: Long-term gastrointestinal sequelae are common after colorectal cancer surgery, but the impact of type 2 diabetes (T2D) is unknown. METHODS: In a cross-sectional design, questionnaires regarding bowel function and quality of life (QoL) were sent to all Danish colorectal cancer survivors, who had undergone surgery between 2001 and 2014 and had more than 2 years follow-up without relapse. The prevalence of long-term gastrointestinal sequelae among colorectal cancer survivors with and without T2D were compared while stratifying for type of surgical resection and adjusting for age, sex, and time since surgery. RESULTS: A total of 8747 out of 14 488 colorectal cancer survivors answered the questionnaire (response rate 60 per cent), consisting of 3116 right-sided colonic, 2861 sigmoid, and 2770 rectal resections. Of these, 690 (7.9 per cent) had a diagnosis of T2D before surgery. Survivors with T2D following rectal resection had a 15 per cent (95 per cent c.i. 7.8 to 22) higher absolute risk of major low anterior resection syndrome, whereas survivors with T2D following right-sided and sigmoid resection had an 8 per cent higher risk of constipation (P < 0.001) but otherwise nearly the same long-term risk of bowel symptoms as those without T2D. For all types of colorectal cancer resections, T2D was associated with a 6–10 per cent higher risk of severe pain (P < 0.035) and a 4–8 per cent higher risk of impaired QoL. CONCLUSION: T2D at time of surgery was associated with a higher risk of long-term bowel dysfunction after rectal resection, but not after colon resection excluding a higher risk of constipation. T2D was associated with a slightly higher frequency of severe pain and inferior QoL after both rectal and colonic cancer resection

A retrospective cohort study on oesophageal food bolus obstruction in the North Denmark region in 2021-two thirds were never diagnosed with a cause

BACKGROUND: Food bolus obstruction (FBO) leading to hospital treatment is often associated with eosinophilic oesophagitis (EoE), stenosis, or oesophageal cancer (1). Danish national guidelines recommend that patients with FBO undergo a diagnostic upper endoscopy within two weeks of presentation to exclude possible malignancy, and histological evaluation of eight biopsies (2, 3).AIMS: The aims of this study were to (1) report the incidence and describe the causes and treatment of FBO in the North Denmark Region (NDR), (2) determine the proportion of patients who underwent upper endoscopy and biopsy according to regional and national guidelines, and (3) identify International Classification of Diseases 10th Revision (ICD-10) diagnosis and procedure codes applied to the hospital visits due to FBO in the NDR.METHODS: Among all acute hospital visits in the NDR in 2021, all visits with ICD-10 codes possibly reflecting FBO, as well as a random sample of 14,400 visits with unspecific ICD-10 codes (R and Z codes), were screened manually for possible FBO. Diagnosis, follow-up, and treatment of all patients with FBO were recorded.RESULTS: The median patient age was 66.0 (Q1-Q3: 49.8-81.0) years, and half of the patients had experienced FBO before. Two thirds of patients (66.0%) were never diagnosed with a cause of FBO, followed by 17.3% with EoE. 30% of patients did not undergo upper endoscopy within two weeks of the hospital visit, and 50.7% were never biopsied in the oesophagus. Of 1886 hospital visits with registry ICD-10 codes that possibly reflected FBO, 8.4% were due to FBO, while FBO was present in 0.028% of the random sample of unspecific ICD-10 codes.CONCLUSIONS: Most hospitalized FBO patients in the NDR in 2021 were never diagnosed with a cause. In these patients there is a high risk of overlooked EoE or upper gastrointestinal cancers. The area needs immediate focus and changed routines to improve treatment and prevent new FBO.</p

Capacitating Community: The Writing Innovation Symposium

The topic of this symposium, capacitating community, invites CLJ readers to consider what makes a community possible. This piece showcases one means, small conferences, via a retrospective on the Writing Innovation Symposium (WIS), a regional event with national scope that has hosted writers and writing educators annually in Milwaukee, WI, since 2018. Through a quilted conversation pieced from hours of small-group discussion, twenty-nine participants across academic and nonacademic ranks, roles, and ranges of experience offer insight into the WIS as well as the nature and value of professional community

A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults

\ua9 2018, The Author(s). Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake