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Reducing the Application Rate of Molluscicide Pellets for the Invasive Spanish Slug, Arion vulgaris. INSECTS 2022; 13:insects13030301. [PMID: 35323599 PMCID: PMC8955816 DOI: 10.3390/insects13030301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/12/2022] [Accepted: 03/15/2022] [Indexed: 12/03/2022]
Abstract
Simple Summary Arion vulgaris has become a major invasive pest slug in Europe, causing extensive damage to many crops. To control this pest, the use of chemical molluscicides remains the most important. However, despite the proved efficacy, they still have detrimental environmental effects. We performed two double-replicated laboratory studies testing molluscicide pellets with metaldehyde (3% and 5%) and iron phosphate (1%) and found the reluctance of slugs to eat a full lethal dose regardless of whether the poison is stronger or weaker. As a consequence, slugs remain alive and only reduce their herbivory by half; the remaining granules or their parts are the main source of toxic effects of molluscicides in the environment. Moreover, a higher metaldehyde content of the pellets does not lead to lower herbivory. The results showed that a new application of molluscicides could be useful; the application rate should be decreased according to the ability of slugs to eat a certain amount of molluscicide pellets. Abstract Arion vulgaris are mostly controlled using chemical molluscicide products, and the detrimental environmental effects of these molluscicides can be reduced by decreasing the number of pellets applied per unit area. The objective of this study was to compare three slug control methods during two double-replicated seven-day laboratory experiments, in which slugs could choose the number of pellets with metaldehyde (3% or 5%) or iron phosphate (1%) and different types of food: leafy plants (lettuce), root vegetables (carrot), a cereal-based diet (oatmeal), or an animal-based diet (dry cat food). Slugs were irrigated and allowed to recover. We found a reluctance of slugs to eat big amounts of pellets and, therefore, to reach a full lethal dose, which resulted in low mortality (the rate was only 2.1%), regardless of whether the poison was stronger or weaker. Herbivory of slugs was in some cases reduced by half, but no treatments resulted in slugs to stop eating. Pellets with 3% metaldehyde were significantly more acceptable than pellets with 5% metaldehyde (uneaten pellets were left). The results showed that the new application of molluscicides could be useful; the application rate should be decreased according to the slugs number and ability of slugs to eat a certain amount of molluscicide pellets.
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Castro-Gutierrez VM, Pickering L, Cambronero-Heinrichs JC, Holden B, Haley J, Jarvis P, Jefferson B, Helgason T, Moir JW, Hassard F. Bioaugmentation of pilot-scale slow sand filters can achieve compliant levels for the micropollutant metaldehyde in a real water matrix. WATER RESEARCH 2022; 211:118071. [PMID: 35063927 DOI: 10.1016/j.watres.2022.118071] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/23/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
Metaldehyde is a polar, mobile, low molecular weight pesticide that is challenging to remove from drinking water with current adsorption-based micropollutant treatment technologies. Alternative strategies to remove this and compounds with similar properties are necessary to ensure an adequate supply of safe and regulation-compliant drinking water. Biological removal of metaldehyde below the 0.1 µg•L-1 regulatory concentration was attained in pilot-scale slow sand filters (SSFs) subject to bioaugmentation with metaldehyde-degrading bacteria. To achieve this, a library of degraders was first screened in bench-scale assays for removal at micropollutant concentrations in progressively more challenging conditions, including a mixed microbial community with multiple carbon sources. The best performing strains, A. calcoaceticus E1 and Sphingobium CMET-H, showed removal rates of 0.0012 µg•h-1•107 cells-1 and 0.019 µg•h-1•107 cells-1 at this scale. These candidates were then used as inocula for bioaugmentation of pilot-scale SSFs. Here, removal of metaldehyde by A. calcoaceticus E1, was insufficient to achieve compliant water regardless testing increasing cell concentrations. Quantification of metaldehyde-degrading genes indicated that aggregation and inadequate distribution of the inoculum in the filters were the likely causes of this outcome. Conversely, bioaugmentation with Sphingobium CMET-H enabled sufficient metaldehyde removal to achieve compliance, with undetectable levels in treated water for at least 14 d (volumetric removal: 0.57 µg•L-1•h-1). Bioaugmentation did not affect the background SSF microbial community, and filter function was maintained throughout the trial. Here it has been shown for the first time that bioaugmentation is an efficient strategy to remove the adsorption-resistant pesticide metaldehyde from a real water matrix in upscaled systems. Swift contaminant removal after inoculum addition and persistent activity are two remarkable attributes of this approach that would allow it to effectively manage peaks in metaldehyde concentrations (due to precipitation or increased application) in incoming raw water by matching them with high enough degrading populations. This study provides an example of how stepwise screening of a diverse collection of degraders can lead to successful bioaugmentation and can be used as a template for other problematic adsorption-resistant compounds in drinking water purification.
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Affiliation(s)
- V M Castro-Gutierrez
- Department of Biology, University of York, Heslington, York, UK; Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK; Environmental Pollution Research Center (CICA), University of Costa Rica, Montes de Oca, 11501, Costa Rica
| | - L Pickering
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK
| | - J C Cambronero-Heinrichs
- Environmental Pollution Research Center (CICA), University of Costa Rica, Montes de Oca, 11501, Costa Rica
| | - B Holden
- UK Water Industry Research Limited, London, UK
| | - J Haley
- UK Water Industry Research Limited, London, UK
| | - P Jarvis
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK
| | - B Jefferson
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK
| | - T Helgason
- Department of Biology, University of York, Heslington, York, UK
| | - J W Moir
- Department of Biology, University of York, Heslington, York, UK
| | - F Hassard
- Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK.
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Niemi L, Landová P, Taggart M, Boyd K, Zhang Z, Gibb S. Spatiotemporal trends and annual fluxes of pharmaceuticals in a Scottish priority catchment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 292:118295. [PMID: 34626711 DOI: 10.1016/j.envpol.2021.118295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/02/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
Pharmaceuticals (a class of emerging contaminants) are continuously introduced into effluent-receiving surface waters due to their incomplete removal within wastewater treatment plants (WWTPs). This work investigated the presence and distribution of eight commonly used human pharmaceuticals in the River Dee (Scotland, UK), a Scottish Environment Protection Agency priority catchment that is a conservation site and important raw water source. Grab sampling and passive sampling (Polar Organic Chemical Integrative Sampler, POCIS) was performed over 12 months, targeting: paracetamol, ibuprofen, and diclofenac (analgesics/anti-inflammatories); clarithromycin and trimethoprim (antibiotics); carbamazepine and fluoxetine (psychoactive drugs); and 17α-ethynylestradiol (estrogen hormone). Sampling sites spanned from the river's rural source to the heavily urbanised estuary into the North Sea. Ibuprofen (ranging 0.8-697 ng/L), paracetamol (ranging 4-658 ng/L), trimethoprim (ranging 3-505 ng/L), diclofenac (ranging 2-324 ng/L) and carbamazepine (ranging 1-222 ng/L) were consistently detected at the highest concentrations through grab sampling, with concentrations generally increasing down river with increasing urbanisation. However, POCIS revealed trace contamination of most compounds throughout the river (commonly <0.5 ng/L), indicating pollution may be related to diffuse sources. Analysis of river flows revealed that low flow and warm seasons corresponded to statistically significantly higher concentrations of diclofenac and carbamazepine, two compounds of environmental and regulatory concern. Below the largest WWTP, annual average fluxes ranged 0.1 kg/yr (clarithromycin) to 143.8 kg/yr (paracetamol), with 226.2 kg/yr for total target compounds. It was estimated that this source contributed >70% of the total mass loads (dissolved phase) of the target compounds in the river. As the River Dee is an important raw water source and conservation site, additional catchment monitoring is warranted to safeguard water quality and assess environmental risk of emerging contaminants, particularly in relation to unusual weather patterns, climate change and population growth.
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Affiliation(s)
- Lydia Niemi
- Environmental Research Institute, University of the Highlands and Islands, Castle Street, Thurso, KW14 7JD, UK; The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
| | - Pavlína Landová
- Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118, 612 00 Brno, Czech Republic
| | - Mark Taggart
- Environmental Research Institute, University of the Highlands and Islands, Castle Street, Thurso, KW14 7JD, UK
| | - Kenneth Boyd
- Environmental Research Institute, University of the Highlands and Islands, Castle Street, Thurso, KW14 7JD, UK
| | - Zulin Zhang
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Stuart Gibb
- Environmental Research Institute, University of the Highlands and Islands, Castle Street, Thurso, KW14 7JD, UK
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4
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Balashova N, Hiscock KM, Reid BJ, Reynolds R. Trends in metaldehyde concentrations and fluxes in a lowland, semi-agricultural catchment in the UK (2008-2018). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148858. [PMID: 34237530 DOI: 10.1016/j.scitotenv.2021.148858] [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: 04/13/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Metaldehyde, a widely used molluscicide, is one of the most commonly detected pesticides in aquatic environments in the UK. In this study, metaldehyde concentrations and fluxes in stream water over a ten-year period (2008-2018) are reported for the River Colne catchment (Essex, southeast England), and the influence of hydrological conditions and application regimes are assessed. In general, peaks in metaldehyde concentration in river water occasionally exceeded 0.25 μg L-1, and concentrations did not typically exceed the European Union Drinking Water Directive (EU DWD) regulatory limit of 0.1 μg L-1. Metaldehyde concentration peaks displayed a seasonal pattern. Metaldehyde concentrations during periods when the molluscicide was not applied to agricultural land (January, July) and during the spring-summer application period (February to June) were generally low (0.01-0.03 μg L-1). Peaks in metaldehyde concentration mainly occurred during the autumn-winter application season (August to December), and were typically associated with high intensity hydrological regimes (daily rainfall ≥10 mm; stream flow up to 18 m3 s-1). Where metaldehyde concentrations exceeded the EU DWD regulatory limit, this was short-lived. The annual flux at the top of the Colne catchment (0.2-0.6 kg a-1) tended to be lower than in the middle of the catchment (0.3-1.4 kg a-1), with maximum flux values observed at the bottom of the catchment (0.5-25.8 kg a-1). Metaldehyde losses from point of application to surface water varied between 0.01 and 0.25%, with a maximum of 1.18% (2012). Annual flux was primarily controlled by the annual precipitation and stream flow (R2 = 0.9) rather than annual metaldehyde use (kg active applied). Precipitation explained 37% and 81% of variability in metaldehyde concentration and flux, respectively. Annual ranges in metaldehyde concentration were greater in the years 2012 and 2014 with an overall reduction in the range of metaldehyde concentrations evident over the period 2015-2018. It is the expectation that metaldehyde concentrations in stream water will continue to decrease following the withdrawal of metaldehyde for outdoor use in the UK from March 2022.
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Affiliation(s)
- Natalia Balashova
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.
| | - Kevin M Hiscock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Brian J Reid
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Richard Reynolds
- Catchment, Coastal and Biodiversity Management Team, Anglian Water Services Ltd., Thorpe Wood House, Peterborough PE3 6WT, UK
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Keighley N, Ramwell C, Sinclair C, Werner D. Highly variable soil dissipation of metaldehyde can explain its environmental persistence and mobility. CHEMOSPHERE 2021; 283:131165. [PMID: 34182634 PMCID: PMC8434416 DOI: 10.1016/j.chemosphere.2021.131165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/20/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
There are increasing concerns about the hazard posed to drinking water resources by persistent, mobile, and toxic (PMT) substances in the environment. For example, the extensive use of metaldehyde-based molluscicide to control slug populations in agricultural fields has frequently led to pollution of surface waters and contamination of drinking water at levels exceeding the statutory limit. Regulatory environmental fate assessments and studies in the literature did not predict that metaldehyde would be persistent in the environment, contrary to observations from monitoring schemes. To understand the reasons for this disparity, this study conducted a suite of degradation experiments, covering different soil types and environmentally realistic conditions in Northern Europe, and generated a distribution of DT50 values for metaldehyde to examine whether degradation rates are underestimated by current risk assessments. The results were found to vary, showing DT50 values ranging from 3.0 to 4150 days, which indicated that metaldehyde had the potential to become persistent. Lack of prior metaldehyde exposure, high moisture content, low temperature, and locally high metaldehyde concentration under pellets were identified as high-risk conditions for low pesticide biodegradation in UK soils.
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Affiliation(s)
- Nathan Keighley
- Fera Science Ltd., York Biotech Campus, Sand Hutton, York, YO41 1LZ, UK; School of Engineering, Newcastle University, NE1 7RU, Newcastle upon Tyne, UK.
| | - Carmel Ramwell
- Fera Science Ltd., York Biotech Campus, Sand Hutton, York, YO41 1LZ, UK.
| | - Chris Sinclair
- Fera Science Ltd., York Biotech Campus, Sand Hutton, York, YO41 1LZ, UK.
| | - David Werner
- School of Engineering, Newcastle University, NE1 7RU, Newcastle upon Tyne, UK.
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de Silva SM, Chesmore D, Smith J, Port G. Listening to Slugs: Acceptability and Consumption of Molluscicide Pellets by the Grey Field Slug, Deroceras reticulatum. INSECTS 2021; 12:548. [PMID: 34208245 PMCID: PMC8230794 DOI: 10.3390/insects12060548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 11/17/2022]
Abstract
Gastropod damage to crop plants has a significant economic impact on agricultural and horticultural industries worldwide, with the Grey Field Slug (Deroceras reticulatum (Müller)) considered the main mollusc pest in the United Kingdom and in many other temperate areas. The prevailing form of crop protection is pellets containing the active ingredient, metaldehyde. Metaldehyde can cause paralysis and death in the mollusc, depending on the amount ingested. The paralysing effects may result in reduced pellet consumption. A greater understanding of metaldehyde consumption may reveal an area that can be manipulated using novel molluscicide formulations. Novel pellet types included commercial metaldehyde pellets coated so that metaldehyde is released more slowly. In both laboratory and arena trials, an audio sensor was used to record individual slugs feeding on a variety of pellet types, including commercially available toxic pellets (metaldehyde and ferric phosphate) and novel metaldehyde formulations. The sensor was used to record the length of each bite and the total number of bites. There was no significant difference in the length of bites between pellet types in laboratory trials. Novel pellets were not consumed more than commercial pellet types. Commercial pellet types did not differ in consumption.
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Affiliation(s)
- Samantha Mirhaya de Silva
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK;
| | - David Chesmore
- Department of Electronic Engineering, The University of York, Heslington, York YO10 5DD, UK; (D.C.); (J.S.)
| | - Jack Smith
- Department of Electronic Engineering, The University of York, Heslington, York YO10 5DD, UK; (D.C.); (J.S.)
| | - Gordon Port
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK;
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Gravell A, Fones GR, Greenwood R, Mills GA. Detection of pharmaceuticals in wastewater effluents-a comparison of the performance of Chemcatcher® and polar organic compound integrative sampler. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:27995-28005. [PMID: 32405945 PMCID: PMC7334249 DOI: 10.1007/s11356-020-09077-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/27/2020] [Indexed: 05/16/2023]
Abstract
Chemcatcher® and POCIS passive sampling devices are widely used for monitoring polar organic pollutants in water. Chemcatcher® uses a bound Horizon Atlantic™ HLB-L sorbent disk as receiving phase, whilst the POCIS uses the same material in the form of loose powder. Both devices (n = 3) were deployed for 21 days in the final effluent at three wastewater treatment plants in South Wales, UK. Following deployment, sampler extracts were analysed using liquid chromatography time-of-flight mass spectrometry. Compounds were identified using an in-house database of pharmaceuticals using a metabolomics workflow. Sixty-eight compounds were identified in all samplers. For the POCIS, substantial losses of sorbent (11-51%) were found during deployment and subsequent laboratory analysis, necessitating the use of a recovery factor. Percentage relative standard deviations varied (with 10 compounds exceeding 30% in both samplers) between individual compounds and between samplers deployed at the three sites. The relative performance of the two devices was evaluated using the mass of analyte sequestered, measured as an integrated peak area. The ratio of the uptake of the pharmaceuticals for the POCIS versus Chemcatcher® was lower (1.84x) than would be expected on the basis of the ratio of active sampling areas (3.01x) of the two devices. The lower than predicted uptake may be attributable to the loose sorbent material moving inside the POCIS when deployed in the field in the vertical plane. In order to overcome this, it is recommended to deploy the POCIS horizontally inside the deployment cage.
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Affiliation(s)
- Anthony Gravell
- Natural Resources Wales, Faraday Building, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Gary R Fones
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3QL, UK.
| | - Richard Greenwood
- School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK
| | - Graham A Mills
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth, PO1 2DT, UK
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Balashova N, Wilderspin S, Cai C, Reid BJ. Ubiquity of microbial capacity to degrade metaldehyde in dissimilar agricultural, allotment and garden soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 704:135412. [PMID: 31837843 DOI: 10.1016/j.scitotenv.2019.135412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Metaldehyde is a molluscicide used to control slugs and snails. Despite its extensive use, very little is known about the capacity of soil microbial communities to degrade this chemical. This research provides a synopsis of the latent capacity of soil microbial communities, present in agricultural (n=14), allotment (n=4) and garden (n=10) soils, to degrade metaldehyde. Extents of 14C-metaldehyde mineralisation across all soils ranged from 17.7 to 60.0%. Pre-exposure (in situ, in the field) to metaldehyde was not observed to consistently increase extents of metaldehyde mineralisation. Where soils were augmented, (ex situ, in the laboratory) with metaldehyde (28 mg kg-1), the mineralisation capacity was increased in some, but not all, soils (uplift ranged from +0.10 to +16.9%). Results indicated that catabolic competence to degrade metaldehyde was evident in both surface (16.7-52.8%) and in sub-surface (30.0-66.4%) soil horizons. Collectively, the results suggest that catabolic competence to degrade metaldehyde was ubiquitous across a diverse range of soil environments; that varied in texture (from sand to silty clay loam), pH (6.15-8.20) and soil organic matter (SOM) content (1.2%-52.1%). Lighter texture soils, in general, were observed to have higher capacity to mineralise metaldehyde. Weak correlations between catabolic competence and soil pH and soil organic matter content were observed; it was noted that above a SOM threshold of 12% metaldehyde mineralisation was always >34%. It was concluded that the common occurrence of metaldehyde in EU waters is unlikely the consequence of low potential for this chemical to be degraded in soil. It is more likely that application regimes (quantities/timings) and meteorological drivers facilitate the transport of metaldehyde from point of application into water resources.
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Affiliation(s)
- Natasha Balashova
- School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Sarah Wilderspin
- School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Chao Cai
- School of Environmental Sciences, University of East Anglia, Norwich, UK; Institute for Urban Environment, Chinese Academy of Sciences, Xiamen, PR China
| | - Brian J Reid
- School of Environmental Sciences, University of East Anglia, Norwich, UK.
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Rimayi C, Chimuka L, Gravell A, Fones GR, Mills GA. Use of the Chemcatcher® passive sampler and time-of-flight mass spectrometry to screen for emerging pollutants in rivers in Gauteng Province of South Africa. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:388. [PMID: 31115701 PMCID: PMC6529598 DOI: 10.1007/s10661-019-7515-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 04/30/2019] [Indexed: 05/06/2023]
Abstract
Many rivers in urbanised catchments in South Africa are polluted by raw sewage and effluent to an extent that their ecological function has been severely impaired. The Hennops and Jukskei Rivers lying in the Hartbeespoort Dam catchment are two of the worst impacted rivers in South Africa and are in need of rehabilitation. Passive sampling (Chemcatcher® with a HLB receiving phase) together with high-resolution tandem mass spectrometry-targeted screening was used to provide high sensitivity and selectivity for the identification of a wide range of emerging pollutants in these urban waters. Over 200 compounds, including pesticides, pharmaceuticals and personal care products, drugs of abuse and their metabolites were identified. Many substances (~ 180) being detected for the first time in surface water in South Africa. General medicines and psychotropic drugs were the two most frequently detected groups in the catchment. These accounted for 49% of the emerging pollutants found. Of the general medicines, antihypertensive agents, beta-blocking and cardiac drugs were the most abundant (28%) classes detected. The Hennops site, downstream of a dysfunctional wastewater treatment plant, was the most polluted with 123 substances detected. From the compounds detected, peak intensity-based prioritisation was used to identify the five most abundant pollutants, being in the order caffeine > lopinavir > sulfamethoxazole > cotinine > trimethoprim. This work provides the largest available high-quality dataset of emerging pollutants detected in South African urban waters. The data generated in this study provides a solid foundation for subsequent work to further characterise (suspect screening) and quantify (target analysis) these substances.
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Affiliation(s)
- Cornelius Rimayi
- Department of Water and Sanitation, Resource Quality Information Services (RQIS), Roodeplaat, P. Bag X313, Pretoria, 0001, South Africa
| | - Luke Chimuka
- School of Chemistry, University of the Witwatersrand, P. Bag 3, Wits, Johannesburg, 2050, South Africa
| | - Anthony Gravell
- Natural Resources Wale, NRW Analytical Services, Swansea University, Faraday Building, Singleton Campus, Swansea, SA2 8PP, UK
| | - Gary R Fones
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3QL, UK.
| | - Graham A Mills
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth, PO1 2DT, UK
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Castle GD, Mills GA, Gravell A, Leggatt A, Stubbs J, Davis R, Fones GR. Comparison of different monitoring methods for the measurement of metaldehyde in surface waters. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:75. [PMID: 30648204 PMCID: PMC6333724 DOI: 10.1007/s10661-019-7221-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/08/2019] [Indexed: 05/28/2023]
Abstract
Metaldehyde is recognised as an emerging contaminant. It is a powerful molluscicide and is the active compound in many types of slug pellets used for the protection of crops. The application of pellets to land generally takes place between August and December when slugs thrive. Due to its high use and physico-chemical properties, metaldehyde can be present in the aquatic environment at concentrations above the EU Drinking Water Directive limit of 100 ng L-1 for a single pesticide. Such high concentrations are problematic when these waters are used in the production of drinking water. Being able to effectively monitor this pollutant of concern is important. We compared four different monitoring techniques (spot and automated bottle sampling, on-line gas chromatography/mass spectrometry (GC/MS) and passive sampling) to estimate the concentration of metaldehyde. Trials were undertaken in the Mimmshall Brook catchment (Hertfordshire, UK) and in a feed in a drinking water treatment plant for differing periods between 17th October and 31st December 2017. This period coincided with the agricultural application of metaldehyde. Overall, there was a good agreement between the concentrations measured by the four techniques, each providing complementary information. The highest resolution data was obtained using the on-line GC/MS. During the study, there was a large exceedance (500 ng L-1) of metaldehyde that entered the treatment plant; but this was not related to rainfall in the area. Each monitoring method had its own advantages and disadvantages for monitoring investigations, particularly in terms of cost and turn-a-round time of data.
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Affiliation(s)
- Glenn D Castle
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3QL, UK
| | - Graham A Mills
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth, PO1 2DT, UK
| | - Anthony Gravell
- Natural Resources Wales, NRW Analytical Services, Swansea University, Faraday Building, Singleton Campus, Swansea, SA2 8PP, UK
| | - Alister Leggatt
- Affinity Water Ltd., Tamblin Way, Hatfield, Hertfordshire, AL10 9EZ, UK
| | - Jeff Stubbs
- Anatune Ltd, Unit 4, Wellbrook Court, Girton Road, Cambridge, CB3 0NA, UK
| | - Richard Davis
- Anatune Ltd, Unit 4, Wellbrook Court, Girton Road, Cambridge, CB3 0NA, UK
| | - Gary R Fones
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3QL, UK.
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