| 1. |
- Bruce, Peter, 1986-, et al.
(författare)
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Inconsistencies in How Environmental Risk Is Evaluated in Sweden for Dumping Dredged Sediment at Sea
- 2021
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Millions of tons of dredged sediment are dumped at sea annually. International conventions limit dumping when there is a risk of adverse ecological effects, for example if the sediment is contaminated. However, the perception of risk differs substantially among stakeholders and in Sweden there is a lack of guidelines for how to address such risk. In the current study, we examined exemptions to the Swedish ban on dumping at sea, to explore the extent of dumping and how ecological aspects were considered in the evaluation of risks. We analyzed data from all cases granted exemption by county administrative boards and all court cases considering exemption to the ban from the beginning of 2015 to June 2020. We found that while dumping is the least common alternative management method for dredged sediment in total number of cases (98/792), dumping is the main method in terms of volume (30.8/38.2 million m3). When considering exemptions, the courts mainly evaluated the risk of exposure to contaminants and resuspended sediment for the environment adjacent to the dumpsite. The risks from contaminants were characterized based on various lines of reasoning, mainly relying on reference values not based on a scientific correlation to environmental risk. We argue that the evaluations were not in line with current regulations and international conventions as they insufficiently accounted for the ecotoxicological risk of the dumped sediment. These issues are potentially similar in other Baltic Sea countries, where there is a similar dependency on binary chemical limit values.
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| 2. |
- Posselt, Malte, et al.
(författare)
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Bacterial Diversity Controls Transformation of Wastewater-Derived Organic Contaminants in River-Simulating Flumes
- 2020
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 54:9, s. 5467-5479
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Tidskriftsartikel (refereegranskat)abstract
- Hyporheic zones are the water-saturated flow-through subsurfaces of rivers which are characterized by the simultaneous occurrence of multiple physical, biological, and chemical processes. Two factors playing a role in the hyporheic attenuation of organic contaminants are sediment bedforms (a major driver of hyporheic exchange) and the composition of the sediment microbial community. How these factors act on the diverse range of organic contaminants encountered downstream from wastewater treatment plants is not well understood. To address this knowledge gap, we investigated dissipation half-lives (DT50s) of 31 substances (mainly pharmaceuticals) under different combinations of bacterial diversity and bedform-induced hyporheic flow using 20 recirculating flumes in a central composite face factorial design. By combining small-volume pore water sampling, targeted analysis, and suspect screening, along with quantitative real-time PCR and time-resolved amplicon Illumina MiSeq sequencing, we determined a comprehensive set of DT50s, associated bacterial communities, and microbial transformation products. The resulting DT50s of parent compounds ranged from 0.5 (fluoxetine) to 306 days (carbamazepine), with 20 substances responding significantly to bacterial diversity and four to both diversity and hyporheic flow. Bacterial taxa that were associated with biodegradation included Acidobacteria (groups 6, 17, and 22), Actinobacteria (Nocardioides and Illumatobacter), Bacteroidetes (Terrimonas and Flavobacterium) and diverse Proteobacteria (Pseudomonadaceae, Sphingomonadaceae, and Xanthomonadaceae). Notable were the formation of valsartan acid from irbesartan and valsartan, the persistence of N-desmethylvenlafaxine across all treatments, and the identification of biuret as a novel transformation product of metformin. Twelve additional target transformation products were identified, which were persistent in either pore or surface water of at least one treatment, indicating their environmental relevance.
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| 3. |
- Abel, Sebastian, 1988-, et al.
(författare)
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Chemical Activity-Based Loading of Artificial Sediments with Organic Pollutants for Bioassays : A Proof of Concept
- 2024
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Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 43:2, s. 279-287
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants (POPs) pose a risk in aquatic environments. In sediment, this risk is frequently evaluated using total or organic carbon-normalized concentrations. However, complex physicochemical sediment characteristics affect POP bioavailability in sediment, making its prediction a challenging task. This task can be addressed using chemical activity, which describes a compound's environmentally effective concentration and can generally be approximated by the degree of saturation for each POP in its matrix. We present a proof of concept to load artificial sediments with POPs to reach a target chemical activity. This approach is envisioned to make laboratory ecotoxicological bioassays more reproducible and reduce the impact of sediment characteristics on the risk assessment. The approach uses a constantly replenished, saturated, aqueous POP solution to equilibrate the organic carbon fraction (e.g., peat) of an artificial sediment, which can be further adjusted to target chemical activities by mixing with clean peat. We demonstrate the applicability of this approach using four polycyclic aromatic hydrocarbons (acenaphthene, fluorene, phenanthrene, and fluoranthene). Within 5 to 17 weeks, the peat slurry reached a chemical equilibrium with the saturated loading solution. We used two different peat batches (subsamples from the same source) to evaluate the approach. Variations in loading kinetics and eventual equilibrium concentrations were evident between the batches, which highlights the impact of even minor disparities in organic carbon properties within two samples of peat originating from the same source. This finding underlines the importance of moving away from sediment risk assessments based on total concentrations. The value of the chemical activity-based loading approach lies in its ability to anticipate similar environmental impacts, even with varying contaminant concentrations.
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| 4. |
- Baptista-Salazar, Carluvy, et al.
(författare)
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Insights into the factors influencing mercury concentrations in tropical reservoir sediments
- 2021
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Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 23:10, s. 1542-1553
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Tidskriftsartikel (refereegranskat)abstract
- Thousands of dams are currently under construction or planned worldwide to meet the growing need for electricity. The creation of reservoirs could, however, lead to conditions that promote the accumulation of mercury (Hg) in surface sediments and the subsequent production of methylmercury (MeHg). Once produced, MeHg can bioaccumulate to harmful levels in organisms. It is unclear to what extent variations in physical features and biogeochemical factors of the reservoir impact Hg accumulation. The objective of this study was to identify key drivers of the accumulation of total Hg (THg) in tropical reservoir sediments. The concentration of THg in all analyzed depth intervals of 22 sediment cores from the five contrasting reservoirs investigated ranged from 16 to 310 ng g(-1) (n = 212, in the different sediment cores, the maximum depth varied from 18 to 96 cm). Our study suggests reservoir size to be an important parameter determining the concentration of THg accumulating in tropical reservoir sediments, with THg ranging up to 50 ng g(-1) in reservoirs with an area exceeding 400 km(2) and from 100 to 200 ng g(-1) in reservoirs with an area less than 80 km(2). In addition to the reservoir size, the role of land use, nutrient loading, biome and sediment properties (e.g., organic carbon content) was tested as potential drivers of THg levels. The principal component analysis conducted suggested THg to be related to the properties of the watershed (high degree of forest cover and low degree of agricultural land use), size and age of the reservoir, water residence time and the levels of nutrients in the reservoir. A direct correlation between THg and tested variables was, however, only observed with the area of the reservoir.
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| 5. |
- Blenckner, Thorsten, et al.
(författare)
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The Baltic Health Index (BHI): Assessing the social-ecological status of the Baltic Sea
- 2021
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Ingår i: People and Nature. - : Wiley. - 2575-8314. ; 3:2, s. 359-375
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Tidskriftsartikel (refereegranskat)abstract
- Improving the health of coastal and open sea marine ecosystems represents a substantial challenge for sustainable marine resource management, since it requires balancing human benefits and impacts on the ocean. This challenge is often exacerbated by incomplete knowledge and lack of tools that measure ocean and coastal ecosystem health in a way that allows consistent monitoring of progress towards predefined management targets. The lack of such tools often limits capabilities to enact and enforce effective governance. We introduce the Baltic Health Index (BHI) as a transparent, collaborative and repeatable assessment tool. The Index complements existing, more ecological-oriented, approaches by including a human dimension on the status of the Baltic Sea, an ecosystem impacted by multiple anthropogenic pressures and governed by a multitude of comprehensive national and international policies. Using a large amount of social-ecological data available, we assessed the health of the Baltic Sea for nine goals that represent the status towards set targets, for example, clean waters, biodiversity, food provision, natural products extraction and tourism. Our results indicate that the overall health of the Baltic Sea is suboptimal (a score of 76 out of 100), and a substantial effort is required to reach the management objectives and associated targets. Subregionally, the lowest BHI scores were measured for carbon storage, contaminants and lasting special places (i.e. marine protected areas), albeit with large spatial variation. Overall, the likely future status of all goals in the BHI averaged for the entire Baltic Sea is better than the present status, indicating a positive trend towards a healthier Baltic Sea. However, in some Baltic Sea basins, the trend for specific goals was decreasing, highlighting locations and issues that should be the focus of management priorities. The BHI outcomes can be used to identify both pan-Baltic and subregional scale management priorities and to illustrate the interconnectedness between goals linked by cumulative pressures. Hence, the information provided by the BHI tool and its further development will contribute towards the fulfilment of the UN Agenda 2030 and its Sustainability Development Goals. A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.
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| 6. |
- Bruce, Peter, 1986-
(författare)
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A Deep Dive into Sediments : Exploring approaches to assess environmental risks and achieving environmental goals in management of contaminated sediments in Sweden
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Contaminated sediments are common, especially near urban and industrialized areas, and they can have negative ecological effects. In three studies, I explore the challenges for environmental management of contaminated sediments, focusing on environmental risk assessment (ERA) in Sweden. I investigate the scientific basis and ecological relevance of the knowledge that is produced in, and evaluated from, assessments. I then relate that knowledge to environmental goals set for general management, but also within individual assessments.Study I identified environmental goals set by society that ERA of contaminated sediment sites should address through a survey conducted among governmental agencies working with contaminated sediment. To investigate to what extent the practice of ERA addressed the goals which had been identified in the survey, the study also analyzed seven cases of ERA, from 2008-2015. Study II reviewed established strategies for assessing risks from contaminated sediments, from four countries. Then, with the ERAs included in study I, the Swedish ERA practice was characterized and contrasted to the review. Study III investigated to what extent dumping dredged sediment at sea was used as an alternative to manage dredged sediments. The study further investigated how courts, in 14 cases from 2015-2020, evaluated environmental risk when considering to allow dumping.The five environmental goals identified as most relevant focused on ecosystem services and management of environmental resources. While the ERAs occasionally addressed these goals, their priorities were not well aligned with that of the agencies (I). In studies II-III, the case-specific goals were not clearly addressed with the methods used. The results indicate that there is a focus on contaminant concentrations and sediment mobility. Four out of the seven ERAs in study II, and none in study III, measured potential effects from contaminants. The ERAs in study II surveyed benthic species and one conducted a toxicity test. When characterizing risk, there was also a frequent use of references not related to toxicity (II-III). Furthermore, uncertainties were not quantified and rarely discussed. Transparency was lacking regarding what weight individual types of measurements had in characterizing risk (II). In study III, sediment accumulation and contaminant concentrations were the decisive factors. However, in evaluating concentrations, the courts’ reasoning was inconsistent. The ERA practice in Sweden does not clearly produce the information needed to effectively characterize or evaluate risk in line with case specific or societal goals and risk underestimating the risks from contaminated sediments.Additional development and research could improve the capability to produce information for efficient management. Issues that should be addressed are, for example, requirements and guidance for designing case specific ERAs, including setting measurement and assessment endpoints in line with the ERA goals; additional types of measurement of contaminant effects; a system for criteria when characterizing risk; and requirements and guidance for how to consider future changes of site-specific conditions, such as climate change.This thesis highlights some of the potential and limitations in the Swedish practice to inspire management in how to incorporate existing best available methods as well as point to additional research needs.
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| 7. |
- Bruce, Peter, et al.
(författare)
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Risk assessments of contaminated sediments from the perspective of weight of evidence strategies – a Swedish case study
- 2021
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Ingår i: Human and Ecological Risk Assessment. - : Informa UK Limited. - 1080-7039 .- 1549-7860. ; 27:5, s. 1366-1387
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Tidskriftsartikel (refereegranskat)abstract
- Several countries currently lack common recommendations specific to Ecological Risk Assessment (ERA) of contaminated sediments and stakeholders report inconsistencies between currently used approaches. The objective of this study was to provide an increased understanding of how ERAs of contaminated sediments are conducted in comparison to established guidelines. For this, we use Sweden as a case study and compare seven ERAs with four internationally established strategies. Our results indicate that contaminant concentrations receive a comparatively high weight, despite a lack of appropriate benchmarks; toxicity measurements are uncommon, while routine in established strategies; and the integration and interpretation of results lack transparency. We identify three areas that may help improve the practice of ERAs: a common approach to benchmarks, recommendations for how to assess toxic effects, and a common approach for integrating and interpreting results.
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| 8. |
- Castro, Mafalda
(författare)
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Chlorinated Paraffins: improved understanding of their bioaccumulation and toxicity in Daphnia magna
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chlorinated paraffins (CPs) are industrial chemicals, mainly used as flame retardants, plasticizers and metal cutting fluids. Their production has reached historically high levels in the last decade, with an annual production exceeding one million tonnes. In 2017, short chain chlorinated paraffins (SCCPs) were regulated due to their Persistent, Bioaccumulative and Toxic (PBT) properties, while medium and long chain chlorinated paraffins (MC and LCCPs) were suggested as alternatives. The high hydrophobicity of CPs, which complicates bioaccumulation and aquatic toxicity testing, has hindered proper hazard identification by regulatory authorities. This project was initiated in response to the insufficient understanding of bioaccumulative and toxicological properties of these chemicals, which have even surpassed the environmental levels of legacy Persistent Organic Pollutants (POPs) in certain regions.The research presented in this thesis, contributes to filling these knowledge gaps by adapting methods for reliable bioaccumulation and aquatic toxicity assessment. In Paper I, passive dosing, traditionally used for other highly hydrophobic compounds, was adapted and validated for CPs. SC, MC and LCCPs partitioned from silicone into water and, when the crustacean Daphnia magna was introduced into the test system, the CPs were observed to be effectively taken up by the test organism. This passive-dosing approach was further used in Paper II, to investigate the bioconcentration and bioaccumulation potential in D. magna. All tested CPs were found to bioaccumulate in daphnids, including highly hydrophobic, long chained CP congeners. The two most bioaccumulative CPs in Paper II (CP-52 and Huels70C) were thereafter used in a chronic toxicity study (Paper III) and significantly decreased population growth and disrupted fatty acid metabolism of D. magna. Finally, in Paper IV, liposome-mediated delivery of chemicals to aquatic biota was adapted for the first time for organic contaminants, including CPs. This approach yielded stable body burdens of the tested chemicals in D. magna and allowed for kinetic and toxicity assessments.Overall, two alternative bioaccumulation and aquatic toxicity testing methods were successfully adapted for technically challenging (industrial) chemicals. These methods allowed the determination of endpoints of scientific and regulatory interest, such as the high bioaccumulation and toxicity potential of CPs, but were also used to demonstrate their metabolic disruption potential in small crustaceans.
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| 9. |
- Coll, Claudia, et al.
(författare)
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Association between Aquatic Micropollutant Dissipation and River Sediment Bacterial Communities
- 2020
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 54:22, s. 14380-14392
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of micropollutant biodegradation is essential to determine the persistence of potentially hazardous chemicals in aquatic ecosystems. We studied the dissipation half-lives of 10 micropollutants in sediment–water incubations (based on the OECD 308 standard) with sediment from two European rivers sampled upstream and downstream of wastewater treatment plant (WWTP) discharge. Dissipation half-lives (DT50s) were highly variable between the tested compounds, ranging from 1.5 to 772 days. Sediment from one river sampled downstream from the WWTP showed the fastest dissipation of all micropollutants after sediment RNA normalization. By characterizing sediment bacteria using 16S rRNA sequences, bacterial community composition of a sediment was associated with its capacity for dissipating micropollutants. Bacterial amplicon sequence variants of the genera Ralstonia, Pseudomonas, Hyphomicrobium, and Novosphingobium, which are known degraders of contaminants, were significantly more abundant in the sediment incubations where fast dissipation was observed. Our study illuminates the limitations of the OECD 308 standard to account for variation of dissipation rates of micropollutants due to differences in bacterial community composition. This limitation is problematic particularly for those compounds with DT50s close to regulatory persistence criteria. Thus, it is essential to consider bacterial community composition as a source of variability in regulatory biodegradation and persistence assessments.
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| 10. |
- Coll Mora, Claudia, 1986-
(författare)
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How to estimate environmental persistence : Understanding persistence of organic micropollutants in rivers from a multidisciplinary perspective
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organic micropollutants such as food additives, pharmaceuticals and personal care products are found in rivers worldwide. Persistence is a key criteria in chemical risk assessment as micropollutants that are persistent pose an exposure hazard to humans and the environment. As biodegradation is the most relevant removal process for many micropollutants in rivers, persistence assessment relies on the estimation of the biodegradation half-life. This thesis presents new approaches to understand the biodegradation of organic pollutants in rivers.The application of Junge relationships (previously established for atmospheric pollutants), to river systems, was investigated in paper I to assess if biodegradation half-lives in the Danube river are correlated with variability in measured concentrations. Model scenarios show Junge relationships could potentially be found in measurements performed near the mouth of the river, but Junge relationships were not found in currently available monitoring data. In paper II an experimental design and response surface model were developed to study the effect of hyporheic exchange (induced by flowing water) and bacterial diversity in sediment on dissipation half-lives of two micropollutants in flumes. Faster dissipation was observed in flumes with high bacterial diversity and higher hyporheic exchange, and thus both variables are relevant to study dissipation processes in rivers. The influence of biological factors beyond bacteria diversity is explored in papers III and IV, by characterizing the bacteria community composition of sediment in OECD 308 bottle incubations (a standard test that is often recommended in risk assessment guidelines). In paper III, higher variation in half-lives (e.g. relative standard deviations > 50%) were found for micropollutants with longer half-lives (e.g. from 40 to more than 120 days). Higher variation in half-lives also corresponded to differences in bacteria community composition and specifically to increased or decreased abundance of certain bacteria genera. Although the exact bacteria genera involved in the biodegradation of the micropollutants cannot be determined in papers II or III, our results suggest bacteria community composition and diversity should be considered in the interpretation of biodegradation half-lives since they are related to variability in biodegradation and to understand extrapolation from laboratory to the field. Finally in paper IV, it is investigated if the bacteria communities are affected by the OECD 308 test conditions. Changes in the bacteria communities in the sediment between the initial river community, the beginning and the end of the incubation, at high and a low concentrations are reported. Overall, 8% of bacteria genera increased or decreased in relative abundance in all comparisons, and it is unclear if these small changes in bacteria communities could have had an effect on the observed half-lives in paper III.This thesis contributes to the understanding of physical and biological factors influencing biodegradation and potential implications for risk assessment of organic micropollutants in rivers.
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