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Gasque-Belz L, Raes K, Park B, Colville C, Siciliano S, Hogan N, Weber L, Campbell P, Peters R, Hanson M, Hecker M. Hazard assessment of complex legacy-contaminated groundwater mixtures using a novel approach method in adult fathead minnows. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133299. [PMID: 38141307 DOI: 10.1016/j.jhazmat.2023.133299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 12/25/2023]
Abstract
Traditional risk assessment methods face challenges in the determination of drivers of toxicity for complex mixtures such as those present at legacy-contaminated sites. Bioassay-driven analysis across several levels of biological organization represents an approach to address these obstacles. This study aimed to apply a novel transcriptomics tool, the EcoToxChip, to characterize the effects of complex mixtures of contaminants in adult fathead minnows (FHMs) and to compare molecular response patterns to higher-level biological responses. Adult FHMs were exposed for 4 and 21 days to groundwater mixtures collected from a legacy-contaminated site. Adult FHM showed significant induction of micronuclei in erythrocytes, decrease in reproductive capacities, and some abnormal appearance of liver histology. Parallel EcoToxChip analyses showed a high proportion of upregulated genes and a few downregulated genes characteristic of compensatory responses. The three most enriched pathways included thyroid endocrine processes, transcription and translation cellular processes, and xenobiotics and reactive oxygen species metabolism. Several of the most differentially regulated genes involved in these biological pathways could be linked to the apical outcomes observed in FHMs. We concluded that molecular responses as determined by EcoToxChip analysis show promise for informing of apical outcomes and could support risk assessments of complex contaminated sites.
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Affiliation(s)
- Laura Gasque-Belz
- Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
| | - Katherine Raes
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Bradley Park
- Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
| | - Carly Colville
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Steven Siciliano
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Natacha Hogan
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lynn Weber
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Rachel Peters
- Federated Co-operatives Limited, Saskatoon, SK, Canada
| | - Mark Hanson
- Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; School of the Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada.
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2
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Cooper RJ, Hiscock KM. Two decades of the EU Water Framework Directive: Evidence of success and failure from a lowland arable catchment (River Wensum, UK). THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161837. [PMID: 36709887 DOI: 10.1016/j.scitotenv.2023.161837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/20/2023] [Accepted: 01/22/2023] [Indexed: 06/18/2023]
Abstract
The EU Water Framework Directive (WFD) is widely regarded as a seminal piece of environmental legislation. However, two decades since its inception, many European waterbodies are failing to meet its ambitious goal to ensure 'good' quantitative and qualitative status. Here, we investigate the impact of the WFD upon the environmentally sensitive yet heavily impacted River Wensum, a lowland arable catchment in eastern England. Compiling a dataset of 10,950 water quality samples collected from 57 sites across the catchment at approximately monthly intervals during 2000-2022, we assess the spatio-temporal dynamics of 12 priority pollutants, identify the major drivers of water quality change, and evaluate current and future compliance with WFD goals. Our analysis reveals improvements in wastewater treatment initiated significant declines (11-50 %) in the concentration of key sewage pollution indicators (phosphorus, ammonium, biological oxygen demand (BOD)) during the early 2000s. Conversely, agricultural pollution indicators (nitrogen, suspended solids, pesticides) displayed either limited change or a deterioration in water quality, with oxidised nitrogen concentrations in particular having increased 23 % during 2015-2022. Concentration spikes of organic chemical contaminants in recent years (propyzamide, tetrachloroethylene) raise concerns about increased riverine pollution from hazardous substances. Similarly, changes in winter (+13 %) and summer (-7 %) discharge over the past two decades have increased the risk of diffuse pollution mobilisation and reduced the dilution of point source pollutants, respectively. By 2022, 'good' or 'high' water quality status for organic matter pollution indicators (dissolved oxygen, BOD, ammonium) was achieved for >98 % of samples, however WFD compliance fell to just 46 % for phosphorus and 1.8 % for nitrogen. Projections to the end of the third River Basin Management Plan cycle (2027) reveal that whilst phosphorus compliance is likely to improve, nitrogen compliance failure will persist due to the existence of catchment legacy stores and climate change induced impacts on nitrogen mobilisation.
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Affiliation(s)
- Richard J Cooper
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Kevin M Hiscock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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Weatherill JJ, Krause S, Ullah S, Cassidy NJ, Levy A, Drijfhout FP, Rivett MO. Revealing chlorinated ethene transformation hotspots in a nitrate-impacted hyporheic zone. WATER RESEARCH 2019; 161:222-231. [PMID: 31200219 DOI: 10.1016/j.watres.2019.05.083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/17/2019] [Accepted: 05/25/2019] [Indexed: 06/09/2023]
Abstract
Hyporheic zones are increasingly thought of as natural bioreactors, capable of transforming and attenuating groundwater pollutants present in diffuse baseflow. An underappreciated scenario in the understanding of contaminant fate in hyporheic zones is the interaction between point-source trichloroethene (TCE) plumes and ubiquitous, non-point source pollutants such as nitrate. This study aims to conceptualise critical biogeochemical gradients in the hyporheic zone which govern the export potential of these redox-sensitive pollutants from carbon-poor, oxic aquifers. Within the TCE plume discharge zone, discrete vertical profiling of the upper 100 cm of sediment pore water chemistry revealed an 80% increase in dissolved organic carbon (DOC) concentrations and 20-60 cm thick hypoxic zones (<2 mg O2 L-1) within which most reactive transport was observed. A 33% reduction of nitrate concentrations coincided with elevated pore water nitrous oxide concentrations as well as the appearance of manganese and the TCE metabolite cis-1,2-dichloroethene (cDCE). Elevated groundwater nitrate concentrations (>50 mg L-1) create a large stoichiometric demand for bioavailable DOC in discharging groundwater. With the benefit of a high-resolution grid of pore water samplers investigating the shallowest 30 cm of hypoxic groundwater flow paths, we identified DOC-rich hotspots associated with submerged vegetation (Ranunculus spp.), where low-energy metabolic processes such as mineral dissolution/reduction, methanogenesis and ammonification dominate. Using a chlorine index metric, we show that enhanced TCE to cDCE transformation takes place within these biogeochemical hotspots, highlighting their relevance for natural plume attenuation.
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Affiliation(s)
- John J Weatherill
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.
| | - Stefan Krause
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | - Sami Ullah
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | | | - Amir Levy
- Lattey Group, Gisborne, Hawkes Bay, New Zealand
| | | | - Michael O Rivett
- GroundH2O plus Ltd., Quinton, Birmingham, UK; Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, UK
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Weatherill JJ, Atashgahi S, Schneidewind U, Krause S, Ullah S, Cassidy N, Rivett MO. Natural attenuation of chlorinated ethenes in hyporheic zones: A review of key biogeochemical processes and in-situ transformation potential. WATER RESEARCH 2018; 128:362-382. [PMID: 29126033 DOI: 10.1016/j.watres.2017.10.059] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 10/12/2017] [Accepted: 10/28/2017] [Indexed: 06/07/2023]
Abstract
Chlorinated ethenes (CEs) are legacy contaminants whose chemical footprint is expected to persist in aquifers around the world for many decades to come. These organohalides have been reported in river systems with concerning prevalence and are thought to be significant chemical stressors in urban water ecosystems. The aquifer-river interface (known as the hyporheic zone) is a critical pathway for CE discharge to surface water bodies in groundwater baseflow. This pore water system may represent a natural bioreactor where anoxic and oxic biotransformation process act in synergy to reduce or even eliminate contaminant fluxes to surface water. Here, we critically review current process understanding of anaerobic CE respiration in the competitive framework of hyporheic zone biogeochemical cycling fuelled by in-situ fermentation of natural organic matter. We conceptualise anoxic-oxic interface development for metabolic and co-metabolic mineralisation by a range of aerobic bacteria with a focus on vinyl chloride degradation pathways. The superimposition of microbial metabolic processes occurring in sediment biofilms and bulk solute transport delivering reactants produces a scale dependence in contaminant transformation rates. Process interpretation is often confounded by the natural geological heterogeneity typical of most riverbed environments. We discuss insights from recent field experience of CE plumes discharging to surface water and present a range of practical monitoring technologies which address this inherent complexity at different spatial scales. Future research must address key dynamics which link supply of limiting reactants, residence times and microbial ecophysiology to better understand the natural attenuation capacity of hyporheic systems.
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Affiliation(s)
| | - Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Uwe Schneidewind
- Department of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany
| | - Stefan Krause
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | - Sami Ullah
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | | | - Michael O Rivett
- Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, UK; GroundH(2)O Plus Ltd., Quinton, Birmingham, UK
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Němeček J, Dolinová I, Macháčková J, Špánek R, Ševců A, Lederer T, Černík M. Stratification of chlorinated ethenes natural attenuation in an alluvial aquifer assessed by hydrochemical and biomolecular tools. CHEMOSPHERE 2017; 184:1157-1167. [PMID: 28672697 DOI: 10.1016/j.chemosphere.2017.06.100] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 06/22/2017] [Accepted: 06/23/2017] [Indexed: 06/07/2023]
Abstract
Biomolecular and hydrochemical tools were used to evaluate natural attenuation of chlorinated ethenes in a Quaternary alluvial aquifer located close to a historical source of large-scale tetrachloroethylene (PCE) contamination. Distinct stratification of redox zones was observed, despite the aquifer's small thickness (2.8 m). The uppermost zone of the target aquifer was characterised by oxygen- and nitrate-reducing conditions, with mixed iron- to sulphate-reducing conditions dominant in the lower zone, along with indications of methanogenesis. Natural attenuation of PCE was strongly influenced by redox heterogeneity, while higher levels of PCE degradation coincided with iron- to sulphate reducing conditions. Next generation sequencing of the middle and/or lower zones identified anaerobic bacteria (Firmicutes, Chloroflexi, Actinobacteria and Bacteroidetes) associated with reductive dechlorination. The relative abundance of dechlorinators (Dehalococcoides mccartyi, Dehalobacter sp.) identified by real-time PCR in soil from the lower levels supports the hypothesis that there is a significant potential for reductive dechlorination of PCE. Local conditions were insufficiently reducing for rapid complete dechlorination of PCE to harmless ethene. For reliable assessment of natural attenuation, or when designing monitoring or remedial systems, vertical stratification of key biological and hydrochemical markers should be analysed as standard, even in shallow aquifers.
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Affiliation(s)
- Jan Němeček
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic; ENACON s.r.o., Krčská 16, CZ-140 00, Prague 4, Czech Republic.
| | - Iva Dolinová
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic
| | - Jiřina Macháčková
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic
| | - Roman Špánek
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic
| | - Alena Ševců
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic
| | - Tomáš Lederer
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic
| | - Miroslav Černík
- Technical University of Liberec, Studentská 2, CZ-461 17, Liberec, Czech Republic
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