| 1. |
- Antoniou, Maria G., et al.
(författare)
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Required ozone doses for removing pharmaceuticals from wastewater effluents
- 2013
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Ingår i: Science of the Total Environment. - Amsterdam : Elsevier BV. - 1879-1026 .- 0048-9697. ; 456, s. 42-49
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the this study was to investigate the ozone dosage required to remove active pharmaceutical ingredients (APIs) from biologically treated wastewater of varying quality, originated from different raw wastewater and wastewater treatment processes. Secondary effluents from six Swedish wastewater treatment plants (WWTP) were spiked with 42 APIs (nominal concentration 1 mu g/L) and treated with different O-3 doses (0.5-12.0 mg/L ozone) in bench-scale experiments. In order to compare the sensitivity of APIs in each matrix, the specific dose of ozone required to achieve reduction by one decade of each investigated API (DDO3) was determined for each effluent by fitting a first order equation to the remaining concentration of API at each applied ozone dose. Ozone dose requirements were found to vary significantly between effluents depending on their matrix characteristics. The specific ozone dose was then normalized to the dissolved organic carbon (DOC) of each effluent. The DDO3/DOC ratios were comparable for each API between the effluents. 15 of the 42 investigated APIs could be classified as easily degradable (DDO3/DOC <= 0.7), while 19 were moderately degradable (0.7 < DDO3/DOC <= 1.4), and 8 were recalcitrant towards O-3-treatment (DDO3/DOC > 1.4). Furthermore, we predict that a reasonable estimate of the ozone dose required to remove any of the investigated APIs may be attained by multiplying the experimental average DDO3/DOC obtained with the actual DOC of any effluent. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Elucidating selection processes for antibiotic resistance in sewage treatment plants using metagenomics
- 2016
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 572, s. 697-712
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Tidskriftsartikel (refereegranskat)abstract
- Sewage treatment plants (STPs) have repeatedly been suggested as “hotspots” for the emergence and dissemination of antibiotic-resistant bacteria. A critical question still unanswered is if selection pressures within STPs, caused by residual antibiotics or other co-selective agents, are sufficient to specifically promote resistance. To address this, we employed shotgun metagenomic sequencing of samples from different steps of the treatment process in three Swedish STPs. In parallel, concentrations of selected antibiotics, biocides and metals were analyzed. We found that concentrations of tetracycline and ciprofloxacin in the influent were above predicted concentrations for resistance selection, however, there was no consistent enrichment of resistance genes to any particular class of antibiotics in the STPs, neither for biocide and metal resistance genes. The most substantial change of the bacterial communities compared to human feces occurred already in the sewage pipes, manifested by a strong shift from obligate to facultative anaerobes. Through the treatment process, resistance genes against antibiotics, biocides and metals were not reduced to the same extent as fecal bacteria. The OXA-48 gene was consistently enriched in surplus and digested sludge. We find this worrying as OXA-48, still rare in Swedish clinical isolates, provides resistance to carbapenems, one of our most critically important classes of antibiotics. Taken together, metagenomics analyses did not provide clear support for specific antibiotic resistance selection. However, stronger selective forces affecting gross taxonomic composition, and with that resistance gene abundances, limit interpretability. Comprehensive analyses of resistant/non-resistant strains within relevant species are therefore warranted.
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| 3. |
- Berglund, Björn, et al.
(författare)
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Efficient removal of antibiotics in surface-flow constructed wetlands, with no observed impact on antibiotic resistance genes
- 2014
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Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 476-477, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- Recently, there have been growing concerns about pharmaceuticals including antibiotics as environmental contaminants. Antibiotics of concentrations commonly encountered in wastewater have been suggested to affect bacterial population dynamics and to promote dissemination of antibiotic resistance. Conventional wastewater treatment processes do not always adequately remove pharmaceuticals causing environmental dissemination of low levels of these compounds. Using constructed wetlands as an additional treatment step after sewage treatment plants have been proposed as a cheap alternative to increase reduction of wastewater contaminants, however this means that the natural microbial community of the wetlands becomes exposed to elevated levels of antibiotics. In this study, experimental surface-flow wetlands in Sweden were continuously exposed to antibiotics of concentrations commonly encountered in wastewater. The aim was to assess the antibiotic removal efficiency of constructed wetlands and to evaluate the impact of low levels of antibiotics on bacterial diversity, resistance development and expression in the wetland bacterial community. Antibiotic concentrations were measured using liquid chromatography-mass spectrometry and the effect on the bacterial diversity was assessed with 16S rRNA-based denaturing gradient gel electrophoresis. Real-time PCR was used to detect and quantify antibiotic resistance genes and integrons in the wetlands, during and after the exposure period. The results indicated that the antibiotic removal efficiency of constructed wetlands was comparable to conventional wastewater treatment schemes. Furthermore, short-term treatment of the constructed wetlands with environmentally relevant concentrations (i.e. 100-2000 ng x 1(-1)) of antibiotics did not significantly affect resistance gene concentrations, suggesting that surface-flow constructed wetlands are well-suited for wastewater treatment purposes. (c) 2014 Elsevier B.V. All rights reserved.
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| 4. |
- Björlenius, Berndt, et al.
(författare)
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Pharmaceutical residues are widespread in Baltic Sea coastal and offshore waters – Screening for pharmaceuticals and modelling of environmental concentrations of carbamazepine
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 633, s. 1496-1509
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Tidskriftsartikel (refereegranskat)abstract
- The consumption of pharmaceuticals worldwide coupled with modest removal efficiencies of sewage treatment plants have resulted in the presence of pharmaceuticals in aquatic systems globally. In this study, we investigated the environmental concentrations of a selection of 93 pharmaceuticals in 43 locations in the Baltic Sea and Skagerrak. The Baltic Sea is vulnerable to anthropogenic activities due to a long turnover time and a sensitive ecosystem in the brackish water. Thirty-nine of 93 pharmaceuticals were detected in at least one sample, with concentrations ranging between 0.01 and 80 ng/L. One of the pharmaceuticals investigated, the anti-epileptic drug carbamazepine, was widespread in coastal and offshore seawaters (present in 37 of 43 samples). In order to predict concentrations of pharmaceuticals in the sub-basins of the Baltic Sea, a mass balance-based grey box model was set up and the persistent, widely used carbamazepine was selected as the model substance. The model was based on hydrological and meteorological sub-basin characteristics, removal data from smaller watersheds and wastewater treatment plants, and statistics relating to population, consumption and excretion rate of carbamazepine in humans. The grey box model predicted average environmental concentrations of carbamazepine in sub-basins with no significant difference from the measured concentrations, amounting to 0.57-3.2 ng/L depending on sub-basin location. In the Baltic Sea, the removal rate of carbamazepine in seawater was estimated to be 6.2 10(-9) s(-1) based on a calculated half-life time of 3.5 years at 10 degrees C, which demonstrates the long response time of the environment to measures phasing out persistent or slowly degradable substances such as carbamazepine. Sampling, analysis and grey box modelling were all valuable in describing the presence and removal of carbamazepine in the Baltic Sea.
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| 5. |
- Carney Almroth, Bethanie, 1974, et al.
(författare)
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Waterborne beclomethasone dipropionate affects the physiology of fish while its metabolite beclomethasone is not taken up
- 2015
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 511, s. 37-46
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Tidskriftsartikel (refereegranskat)abstract
- Asthma is commonly treated with inhalable glucocorticosteroids, including beclomethasone dipropionate (BDP). This is a synthetic prodrug which is metabolized to the more active monopropionate (BMP) and free beclomethasone in humans. To evaluate potential effects of residual drugs on fish, we conducted a 14 day flow-through exposure experiment with BDP and beclomethasone using rainbow trout, and analyzed effects on plasma glucose, hepatic glutathione and catalase activity together with water and body concentrations of the BDP, BMP and beclomethasone. We also analyzed hepatic gene expression in BDP-exposed fish by microarray and quantitative PCR. Beclomethasone (up to 0.65 μg/L) was not taken up in the fish while BDP (0.65 and 0.07 μg/L) resulted in accumulation of both beclomethasone, BMP and BDP in plasma, reaching levels up to those found in humans during therapy. Accordingly, exposure to 0.65 μg/L of BDP significantly increased blood glucose as well as oxidized glutathione levels and catalase activity in the liver. Exposure to beclomethasone or the low concentration of BDP had no effect on these endpoints. Both exposure concentrations of BDP resulted in significantly higher transcript abundance of phosphoenolpyruvate carboxykinase involved in gluconeogenesis, and of genes involved in immune responses. As only the rapidly metabolized prodrug was potent in fish, the environmental risks associated with the use of BDP are probably small. However, the observed physiological effects in fish of BDP at plasma concentrations known to affect human physiology provides valuable input to the development of read-across approaches in the identification of pharmaceuticals of environmental concern.
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| 6. |
- Cerveny, Daniel, et al.
(författare)
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Bioconcentration and behavioral effects of four benzodiazepines and their environmentally relevant mixture in wild fish
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 702
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Tidskriftsartikel (refereegranskat)abstract
- We studied the adverse effects of four benzodiazepines frequently measured in European surface waters. We evaluated bioaccumulation potential of oxazepam, bromazepam, temazepam, and clobazam in freshwater fish species - perch (Perca fluviatilis) and we conducted a series of behavioral trials to assess their potential to alter boldness, activity, and social behavior. All selected endpoints were studied individually for each target benzodiazepine and as a mixture of all tested compounds to assess possible combinatory effects. We used a three-dimensional automated tracking system to quantify the fish behavior. The four compounds bioconcentrated differently in fish muscle (temazepam > clobazam > oxazepam > bromazepam) at high exposure (9.1, 6.9, 5.7, 8.1 mu g L-1, respectively) and low exposure (0.5, 0.5, 0.3, 0.4 mu g L-1, respectively) concentrations. A significant amount of oxazepam was also measured in fish exposed to temazepam, most likely because of the metabolic transformation of temazepam within the fish. Bromazepam, temazepam, and clobazam significantly affected fish behavior at high concentration, while no statistically significant changes were registered for oxazepam. The studied benzodiazepines affected behavior in combination, because the mixture treatment significantly changed several important behavioral traits even at low concentration, while no single compound exposure had such an effect at that dose. Based on our results, we conclude that effects of pharmaceuticals on aquatic environments could be underestimated if risk assessments only rely on the evaluation of single compounds. More studies focused on the combinatory effects of environmentally relevant mixtures of pharmaceuticals are necessary to fill the gaps in this knowledge. (C) 2019 Elsevier B.V. All rights reserved.
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| 7. |
- Duarte, Irina A., et al.
(författare)
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Bioconcentration of neuroactive pharmaceuticals in fish: Relation to lipophilicity, experimental design and toxicity in the aquatic environment
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 812
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Tidskriftsartikel (refereegranskat)abstract
- Uptake of contaminants is linked to their toxicity and is usually estimated through their lipophilicity (logKow). Here, we review current literature regarding bioconcentration, i.e. uptake of contaminants from the external environment only, and the effects of exposure to neuroactive pharmaceuticals in fish. We aim to determine if lipophilicity is a suitable predictor of bioconcentration of these compounds in fish, to identify major drivers of bioconcentration and explore the link between bioconcentration potential and toxicity, focusing on survival, growth, condition, behaviour and reproduction endpoints. Additionally, we compare concentrations known to elicit significant effects in fish with current environmental concentrations, identifying exposure risk in ecosystems. The majority of studies have focused on antidepressants, mainly fluoxetine, and encompasses mostly freshwater species. Few studies determined pharmaceuticals bioconcentration, and even a smaller portion combined bioconcentration with other toxicity endpoints. Results show that lipophilicity isn't a good predictor of neuroactive pharmaceuticals' bioconcentration in fish, which in turn is highly influenced by experimental parameters, including abiotic conditions, species and life-stage. The need for increased standardization of experimental settings is key towards improving accuracy of environmental risk assessments and application in future regulatory schemes. Still, increased fish lethality was linked to increased bioconcentration, yet no other correlations were observed when considering effects on growth, condition, behaviour or reproduction, likely as a result of insufficient and variable data. In the context of current environmental concentrations, several neuroactive pharmaceuticals were found to be potentially threatening, while data on occurrence is lacking for some compounds, particularly in brackish/marine systems. Specifically, nine compounds (fluoxetine, citalopram, sertraline, amitriptyline, venlafaxine, clozapine, carbamazepine, metamfetamine and oxazepam) were found at concentrations either above or critically close to minimum response concentrations, thus likely to affect fish in freshwater and brackish or marine environments, which supports further exploration in risk management strategies and monitoring programs in aquatic environments.
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| 8. |
- Faleye, A. C., et al.
(författare)
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Concentration and reduction of antibiotic residues in selected wastewater treatment plants and receiving waterbodies in Durban, South Africa
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 678, s. 10-20
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Tidskriftsartikel (refereegranskat)abstract
- In the province of KwaZulu-Natal, South Africa the incidence of resistant tuberculosis, upper respiratory tract diseases as well as diarrhoeal and parasitic infections is high. Treatment of these diseases with antibiotics is partly reflected by the excretion of the respective antibiotics and their subsequent occurrence in wastewater. Their quantitative reduction in wastewater treatment reflects their potential environmental as well as human impact, the latter due to the use of the recipient water for domestic purposes and for irrigation. Information of the occurrence and reduction of different classes of antibiotics in wastewater treatment is sparse, especially the particle bound fraction of these. Due to this, analyses of aqueous and particle bound antibiotics in untreated wastewater of four selected wastewater treatment plants (WWTPs) and their receiving water bodies was carried out in Durban, South Africa. The treatment step especially considered was the biological one, represented by activated sludge and trickling filters. The treatment further included secondary clarifiers and final chlorine disinfection. Composite samples were collected during the period February 2017 to May 2017 and analysed with online solid phase extraction - high performance liquid chromatography mass spectrometry (SPE-HPLC-MS). For the 13 assessed antibiotics, the limit of detection (LOD) and the limit of quantification (LOQ) ranged from 0.07 to 0.33 ng L-1 and 0.23 to 1.09 ng L-1 respectively, while the total percentage recovery was in the range of 51 to 111%. The percentage of individual antibiotics bound to the particulate fraction normally lost by sample (influent) filtration, if not analysed in parallel, was in the range of 2.6%-97.3% (n = 32). In this fraction (sludge from centrifuge sample), the concentration of bound antibiotics of all the target antibiotics were detected in the influent of all WWTP in concentration ranges between 1.3 ng L-1 (Azithromycin; AZI) to 81,748 ng(-1) (Ciprofloxacin; CIP). The antibiotics with the highest median concentrations in receiving water bodies of the respective WWTP were: Sulfamethoxazole; SUL (239 ng L-1) WWTP "K", Ciprofloxacin; CIP (708 ng L-1) WWTP "S" and Albendazole; ALB (325 ng L-1 and 683 ng L-1) WWTP "P" and "I" respectively.The overall percentage removal efficiency for the four WWTPs ranged from 21% to 100%. The biological treatment steps, activated sludge and trickling filters, were effective in removing antibiotics especially with the trickling filter and the impact of the sedimentation stage after activated sludge treatment. (C) 2019 Elsevier B.V. All rights reserved.
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| 9. |
- Grabicova, K, et al.
(författare)
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Tissue-specific bioconcentration of antidepressants in fish exposed to effluent from a municipal sewage treatment plant
- 2014
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 488-489, s. 46-50
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Tidskriftsartikel (refereegranskat)abstract
- Tissue-specific bioconcentration of selected antidepressants was studied in rainbow trout (Oncorhynchus mykiss) exposed to undiluted effluent from a Swedish municipal sewage treatment plant for 13 days. Citalopram, sertraline and venlafaxine were found in the brains and livers of most fish, but not in blood plasma or muscle. Venlafaxine was the only drug found in plasma (3/20 fish). Fluoxetine was not detected in any fish tissue, in accordance with a low concentration in the effluent and a comparably high limit of quantification in tissues. Concentrations of citalopram, sertraline and venlafaxine in fish brain were up to 1/12, 1/8 and 1/26, respectively, of the lowest concentrations found in the brains of mammals treated with therapeutic doses. Thus, given co-exposure to several antidepressants and an assumed similar potency in fish, the margin of safety for target-related effects in fish residing in effluent-dominated streams is relatively low. Furthermore, the non-detectable levels of these drugs in blood plasma suggest that analyses of concentrations in target tissues (brain) would be more informative in field studies and other studies with environmentally realistic exposure concentrations.
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| 10. |
- Hagberg, Aleksandra, et al.
(författare)
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Do environmental pharmaceuticals affect the composition of bacterial communities in a freshwater stream? : A case study of the Knivsta river in the south of Sweden
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 763
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Tidskriftsartikel (refereegranskat)abstract
- Pharmaceutical substances present at low concentrations in the environment may cause effects on biological systems such as microbial consortia living on solid riverbed substrates. These consortia are an important part of the river ecosystem as they form part of the food chain. This case study aims to contribute to an increased understanding of how low levels of pharmaceuticals in freshwater streams may influence sessile bacterial consortia. An important point source for pharmaceutical release into the environment is treated household sewage water. In order to investigate what types of effects may occur, we collected water samples as well as riverbed substrates from a small stream in the south of Sweden, Knivstaån, upstream and downstream from a sewage treatment plant (STP). Data from these samples formed the base of this case study where we investigated both the presence of pharmaceuticals in the water and bacterial composition on riverbed substrates. In the water downstream from the STP, 19 different pharmaceuticals were detected at levels below 800 ng/dm3. The microbial composition was obtained from sequencing 16S rRNA genes directly from substrates as well as from cultivated isolates. The cultivated strains showed reduced species variability compared with the data obtained directly from the substrates. No systematic differences were observed following the sampling season. However, differences could be seen between samples upstream and downstream from the STP effluent. We further observed large similarities in bacterial composition on natural stones compared to sterile stones introduced into the river approximately two months prior to sampling, giving indications for future sampling methodology of biofilms.
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