| 1. |
- Augustsson, Anna, et al.
(author)
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Failure of generic risk assessment model framework to predict groundwater pollution risk at hundreds of metal contaminated sites : Implications for research needs
- 2020
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In: Environmental Research. - : Elsevier. - 0013-9351 .- 1096-0953. ; 185, s. 1-9
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Journal article (peer-reviewed)abstract
- Soil pollution constitutes one of the major threats to public health, where spreading to groundwater is one of several critical aspects. In most internationally adopted frameworks for routine risk assessments of contaminated land, generic models and soil guideline values are cornerstones. In order to protect the groundwater at contaminated sites, a common practice worldwide today is to depart from health risk-based limit concentrations for groundwater, and use generic soil-to-groundwater spreading models to back-calculate corresponding equilibrium levels (concentration limits) in soil, which must not be exceeded at the site. This study presents an extensive survey of how actual soil and groundwater concentrations, compiled for all high-priority contaminated sites in Sweden, relate to the national model for risk management of contaminated sites, with focus on As, Cu, Pb and Zn. Results show that soil metal concentrations, as well as total amounts, constitute a poor basis for assessing groundwater contamination status. The evaluated model was essentially incapable of predicting groundwater contamination (i.e. concentrations above limit values) based on soil data, and erred on the "unsafe side" in a significant number of cases, with modelled correlations not being conservative enough. Further, the risk of groundwater contamination was almost entirely independent of industry type. In essence, since neither soil contaminant loads nor industry type is conclusive, there is a need for a supportive framework for assessing metal spreading to groundwater accounting for site-specific, geochemical conditions.
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| 2. |
- Berggren, Lilian, 1953-, et al.
(author)
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A First Examination of the Role of International Child Development Programme in School Achievement
- 2021
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In: Scandinavian Journal of Educational Research. - : Routledge. - 0031-3831 .- 1470-1170. ; 65:3, s. 359-372
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Journal article (peer-reviewed)abstract
- The aim of this study was to explore whether the classroomi mplementation of the International Child Development Programme (ICDP) for secondary school students (grade 9) was linked to better school achievement. The goal of the ICDP is to increase school achievement by promoting positive teacher-student relationships. The study, performed in Sweden, applied a pre–post design (four years) with matched intervention and control schools (N = 148). The post-intervention assessments showed that there were significant differences in school achievement in Grade 9 between the intervention school andthe control school. Specifically, a greater proportion of students at the intervention school demonstrated improvement in school subjects and achieved the competency requirements to enter an upper secondary school programme. Based on the results, the ICDP can be considered an important intervention to promote student learning by promoting positive teacher-student relationships.
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| 3. |
- Berggren, Terese, et al.
(author)
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Warmer water increases early body growth of northern pike (Esox lucius), but mortality has larger impact on decreasing body sizes
- 2021
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In: Canadian Journal of Fisheries and Aquatic Sciences. - : Canadian Science Publishing. - 0706-652X .- 1205-7533. ; 79, s. 771-781
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Journal article (peer-reviewed)abstract
- Large fish species often display truncated size distributions related to harvest. In addition, temperature, food availability and density dependence affect body growth and together with natural mortality influence population size structure. Here we study changes in body growth, size distributions and mortality in both harvested and nonharvested populations of northern pike (Esox Lucius) over 50 years along the Baltic Sea coast and in Lake Malaren, Sweden. For coastal pike, body growth has increased coincidentally with increasing water temperatures, yet in the last two decades there has been a decrease of larger individuals. In Lake Malaren, in contrast, size distributions and body growth were stationary despite similar increases in water temperature. A dominance of slow-growing individuals in older age classes was evident in all studied populations, also in the no-take zone, suggesting other factors than fishing contribute to the mortality pattern. We propose that increasing temperatures have favoured body growth in coastal areas, but this has been counteracted by increased mortality, causing pike sizes to decline. To regain larger coastal pike, managers need to consider multiple measures that reduce mortality.
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| 4. |
- Uddh Söderberg, Terese, 1976-, et al.
(author)
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Challenges in geochemical modelling of metal(loid) solubility and binding mechanisms along a soil profile at a multi-contaminated site
- 2024
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In: Applied Geochemistry. - : Elsevier. - 0883-2927 .- 1872-9134. ; 170
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Journal article (peer-reviewed)abstract
- Recognising the need for robust models in predicting groundwater contamination risks from metal(loid)s in contaminated topsoil, this study focuses on the geochemical behaviour of As, Cd, Cu, Pb, Sb and Zn in one of Sweden’s most heavily contaminated areas. Samples were collected from the waste zone and underlying subsoil down to 5 meters and batch experiments were carried out to assess pH-dependent solubility. The results indicate that Cd, Cu, Pb and Zn are efficiently immobilized in the waste zone, while As(V) and Sb(V) are more easily leached. With the exception of Pb and Cu at high pH, the mobilized metals appear to be predominantly in a truly dissolved state, as confirmed by ultrafiltration at 10 kDa.Speciation modelling using Visual MINTEQ did not suggest a significant role of precipitates such as Zn or Pb arsenates and phosphates, although their involvement could not be ruled out. To better understand sorption/desorption patterns, a multi-surface geochemical model was established, drawing on the Stockholm Humic and CD-MUSIC models for organic matter and Fe/Al (hydr)oxide sorption. However, when default parameters were used, the model consistently overestimated the solubility of Cd, Cu, Pb and Zn in both the waste zone and the uncontaminated subsoil. In contrast, As(V) solubility was generally underestimated, also when the reactive surface area of the Fe- and Al (hydr)oxides was decreased in the model. The model's performance was better for Sb(V), though not without imperfections. When the parameters for organic matter were adjusted such that 100% of the solid-phase organic matter was active with respect to ion binding, but only 25% of the dissolved organic matter, the model description improved considerably for Pb and Cu in the upper soil layers. The model revealed distinct differences in the adsorption behaviour of the metal cations, with Pb being sorbed mostly to Fe/Al (hydroxides), whereas a considerable part of Cu was sorbed to organic matter, particularly in the waste zone.Possibly, the dissolution of easily weatherable metal-containing mineral phases may have contributed to the poor model performance for Cd, Zn and for Cu in the deeper soil layers, although other factors, such as a contribution of hydrous SiO2 or Mn oxides to metal binding, could not be ruled out. Metal sorption to carbonate phases may also have been a contributing factor in the waste zone. Lastly, the reactivity of Fe- and Al (hydr)oxides may have been overestimated by oxalate extraction when default parameters for high-surface-area ferrihydrite were applied. These findings provide valuable insights for environmental management and underscore the need for a more detailed characterization of metal(loid) sorption in contaminated soils, as well as the development of improved modelling strategies to enhance solubility predictions.
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| 5. |
- Uddh Söderberg, Terese, 1976-, et al.
(author)
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Heavy metal transport at a contaminated glassworks site in southeast Sweden.
- 2016
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Conference paper (other academic/artistic)abstract
- Heavy metal transport at a contaminated glassworks site in southeast Sweden.In the “Kingdom of crystal” in southeastern Sweden there are a large number of glassworks sites, which are characterized by high pollution levels of a number of metal contaminants. At Pukeberg glassworks site, which is the focus of this study, As, Ba, Cd, Pb, Sb and Zn are present in significantly elevated levels. For this study, which aim is to characterize the release of metals from the glass waste into soil water and groundwater, 54 soil samples from both saturated and unsaturated zone were gathered. Soil water were sampled from lysimeters installed on the landfill area and groundwater were collected from sampling tubes located upstream, at and downstream of the landfill area. The collected samples were analyzed and distribution coefficients (Kd) were calculated as the ratio of the average pseudo-total metal concentrations in soil (from the landfill site with visible glass) to the average dissolved metal concentrations in soil water to describe the leachability of the metal(loid) in the wastes.High concentrations of metal(loid)s were found in soil water samples at the landfill (collected at 30 and 60 cm depth), indicating that metals are leached from the solid waste materials. The distribution coefficients indicate the highest leachability for Ba (Kd= 150 l/kg) and Sb (Kd= 190 l/kg), a moderately leachability for Cd (Kd= 860 l/kg) and Zn (Kd= 500) and the lowest leachability for As and Pb (Kd= 6000 and 16000 respectively). Examining the soil profiles shows that the metal concentrations are considerable lower when there are no visible glass wastes in the soil, which implies that the majority of leached metals are retained in the waste pile. Significant sorption is also suggested by the low concentrations measured in the groundwater samples. The theoretical dilution of the catchment area alone, cannot explain the decrease in metal concentration between the soil water and the groundwater. With exception for Sb, that seems to move relatively unrestrained from the unsaturated zone to the saturated zone.The results indicate that there are sorption processes involved, preventing or slowing down the transport of the investigated metals through the unsaturated zone. The responsible geochemical processes need to be established before assessing remediation strategies for the contaminated area, as it gives information on the factors controlling the metal leaching.
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| 6. |
- Uddh Söderberg, Terese, 1976-, et al.
(author)
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Metal solubility and transport at a contaminated landfill site – From the source zone into the groundwater
- 2019
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In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 668, s. 1064-1076
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Journal article (peer-reviewed)abstract
- Risks associated with metal contaminated sites are tightly linked to material leachability and contaminant mobility. In this study, metal solubility and transport were characterized within a glass waste landfill through i) lysimeter-collection of pore water and standardized batch leaching tests, ii) soil profiles extending from the landfill surface, through unsaturated soil underneath, and into the groundwater zone, and iii) groundwater samples upstream, at, and downstream of the landfill. The soil analyzes targeted both pseudo-total and geochemically active concentrations of contaminant metals (As, Cd, Pb, Sb) and basic soil geochemistry (pH, org. C, Fe,Mn). Water samples were analyzed for dissolved, colloid-bound and particulate metals, and speciation modelling of the aqueous phase was conducted. The results revealed a highly contaminated system, with mean metal concentrationsin the waste zone between 90 and 250 times the regional background levels. Despite severe contamination of the waste zone and high geochemically active fractions (80–100%) of all contaminant metals as well as elevated concentrations in landfill pore water, the concentrations of Cd and Pb decrease abruptly at the transition between landfill and underlying natural soil and no indication of groundwater contamination was found. The efficient cation retention is likely due to the high pH. However, the sorption of As and Sb is weaker at such high pH,which explains their higher mobility from the pore water zone into groundwater. The field soil:solution for Pb, ranging from 140 to 2,900,000 l kg−1), despite little variability in basic geochemical variables, which we suggest is due to waste material heterogeneity.
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