| 1. |
- Ardalani, Hamidreza, et al.
(författare)
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Dietary quercetin impacts the concentration of pesticides in honey bees
- 2021
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 262
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Tidskriftsartikel (refereegranskat)abstract
- Honey bees are important pollinators and are subject to numerous stressors, such as changing floral resources, parasites, and agrochemical exposure. Pesticide exposure has been linked to the decline in the global honey bee population. We have limited knowledge of the metabolic pathways and synergistic effects of xenobiotics in bees. Quercetin is one of the most abundant phytochemicals in plants and is therefore abundant in the honey bee diet. Quercetin can upregulate the detoxification system in honey bees; however, it is still unknown to what extent quercetin ingestion can reduce the content of absorbed pesticides. In this study, we investigated the effect of dietary quercetin on the contents of three pesticides in honey bees: imidacloprid (insecticide), tebuconazole (fungicide), and tau-fluvalinate (insecticide and acaricide). Bees were divided into two main groups and fed either quercetin-sucrose paste or only sucrose for 72 h. Thereafter, they were orally exposed to ∼10 ng/bee imidacloprid or contact-exposed to ∼0.9 μg/bee tau-fluvalinate or ∼5.2 μg/bee tebuconazole. After 1 h of oral exposure or 24 h of contact exposure, the bees were anaesthetised with CO2, sacrificed by freezing, and extracted with a validated QuEChERS method. Subsequently, the concentrations of the three pesticides and quercetin in the bees were determined with a triple quadrupole tandem mass spectrometer coupled to an HPLC system. No significant effect on the concentration of tebuconazole or tau-fluvalinate was observed in bees fed quercetin. Intake of quercetin led to a reduction in the concentration of imidacloprid in honey bees. Quercetin-rich plants may be exploited in future beekeeping.
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| 2. |
- Daneshvar, Atlasi, et al.
(författare)
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Evaluating pharmaceuticals and caffeine as indicators of fecal contamination in drinking water sources of the Greater Montreal region
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 88:1, s. 131-139
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Tidskriftsartikel (refereegranskat)abstract
- We surveyed four different river systems in the Greater Montreal region, upstream and downstream of entry points of contamination, from April 2007 to January 2009. The studied compounds belong to three different groups: PPCPs (caffeine, carbamazepine, naproxen, gemfibrozil, and trimethoprim), hormones (progesterone, estrone, and estradiol), and triazine herbicides and their metabolites (atrazine, deethylatrazine, deisopropylatrazine, simazine, and cyanazine). In the system A. B, and C having low flow rate and high TOC, we observed the highest detection frequencies and mass flows of PPCPs compared to the other compounds, reflecting discharge of urban contaminations through WWTPs and CSOs. However, in River D, having high flow rate and low TOC, comparable frequency of detection of triazine and their by-products and PPCPs, reflecting cumulative loads of these compounds from the Great Lakes as well as persistency against natural attenuation processes. Considering large differences in the removal efficiencies of caffeine and carbamazepine, a high ratio of caffeine/carbamazepine might be an indicative of a greater proportion of raw sewage versus treated wastewater in surface waters. In addition, caffeine appeared to be a promising indicator of recent urban fecal contaminations, as shown by the significant correlation with FC (R-2 = 0.45), while carbamazepine is a good indicator of cumulative persistence compounds.
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| 3. |
- Daneshvar, Atlasi, et al.
(författare)
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Seasonal variations in the occurrence and fate of basic and neutral pharmaceuticals in a Swedish river-lake system
- 2010
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 80:3, s. 301-309
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Tidskriftsartikel (refereegranskat)abstract
- The seasonal variations in the occurrence of carbamazepine, atenolol, metoprolol, sotalol, and acebutolol were studied at seven sites along River Fyris from December 2007 to December 2008. Samples were collected from the effluent of a waste water treatment plant (WWTP), at one upstream site, and five downstream sites of the WWTP). During one occasion in May 2008, water samples were collected at different locations and depths in the recipient lake. All analytes except of acebutolol were present in both the river and the lake at quantifiable amounts at all sampling occasions. Carbamazepine was found in similar concentrations (about 90 ng L-1) at all sampling sites and all studied depths (0.5-40 m) in the lake, indicating high environmental persistence of this compound. A clear seasonal pattern was observed for the natural attenuation of the beta-blockers in the river, with the highest attenuation occurring in summer and the lowest in winter. The loss of beta-blockers on a distance of 1320 m reached up to 75% during summer time but was insignificant during winter. The seasonal variations in the loss followed the seasonal variations in water temperature and chlorophyll a mass flow suggesting that biotransformation and adsorption are the main processes responsible for the loss of the studied pharmaceuticals in River Fyris downstream the WWTP.
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| 4. |
- Jansson, Stina, et al.
(författare)
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Characterisation and fingerprinting of PCBs in flue gas and ash from waste incineration and in technical mixtures
- 2011
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 85:3, s. 509-515
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Tidskriftsartikel (refereegranskat)abstract
- Congener patterns of mono- to deca-chlorinated biphenyls (PC(1-10)B) were evaluated in (a) waste incineration flue gases collected in the post-combustion zone of a laboratory-scale fluidized-bed reactor, (b) ashes from two different MSW incineration plants, and (c) published data of eight Aroclor formulations. The congener patterns of the flue gases, ashes, and Aroclor mixtures clearly differed from each other, likely reflecting differences in formation pathways. The flue gas congener patterns were largely dominated by the least chlorinated congeners, whereas the ashes displayed more evenly distributed patterns. The most abundant congeners indicated a preference for 3,3',4,4'-oriented substitution, which may be related to de novo-type formation involving perylene. Principal component analysis confirmed that congener patterns differed among the three matrices and also distinguished flue gases collected at 200°C from those collected at 300°C and 450°C. This distinction could be partly explained by the degree of chlorination, although the substitution status of the ortho-position, and substitution in the 3,3',4,4'-positions also seemed to be influential. Injecting biphenyl into the post-combustion zone of the reactor did not alter the patterns, indicating that availability of the backbone structure is not a limiting factor for PCB formation.
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| 5. |
- Kylin, Henrik
(författare)
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Dioxin-like chemicals in soil and sediment from residential and industrial areas in central South Africa
- 2009
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 76, s. 774-783
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants (POPs) are a global concern due to their ubiquitous presence and toxicity. Currently, there is a lack of information regarding POPs from South Africa. Here we report and interpret concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs) and co-planarbiphenyls (PCBs) in soils and sediments collected from central South Africa. High resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) and the H41IE-luc bio-assay were used to identify and quantify individual PCDD/F congeners and to report the total concentration of 2,3,7,8-tetrachloro dibenzo-p-dioxin equivalents (TCDD-EQ), respectively. TCDD-EQs determined by use of the bio-assay, and concentrations of WHO(2005)-TEQ (toxic equivalents) determined by chemical analysis, were similar. The limit of detection (LOD) for the bio-assay was 0.82 and 2.8 ng TCDD-EQ kg(-1), dw for sediment and soil, respectively. EQ20 concentrations determined by use of the bio-assay ranged from
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| 6. |
- Åkerblom, Staffan, et al.
(författare)
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Temporal change estimation of mercury concentrations in northern pike (Esox lucius L.) in Swedish lakes
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 86:5, s. 439-445
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Tidskriftsartikel (refereegranskat)abstract
- Adequate temporal trend analysis of mercury (Hg) in freshwater ecosystems is critical to evaluate if actions from the human society have affected Hg concentrations ([Hg]) in fresh water biota. This study examined temporal change in [Hg] in Northern pike (Esox lucius L.) in Swedish freshwater lakes between 1994 and 2006. To achieve this were lake-specific, multiple-linear-regression models used to estimate pike [Hg], including indicator variables representing time and fish weight and their interactions. This approach permitted estimation of the direction and magnitude of temporal changes in 25 lakes selected from the Swedish national database on Hg in freshwater biota. A significant increase was found in 36% of the studied lakes with an average increase in pike [Hg] of 3.7 +/- 6.7% per year that was found to be positively correlated with total organic carbon. For lakes with a significant temporal change the dataset was based on a mean of 30 fish, while for lakes with no temporal change it was based on a mean of 13 fish.
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| 7. |
- Acevedo, F., et al.
(författare)
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Degradation of polycyclic aromatic hydrocarbons by free and nanoclay-immobilized manganese peroxidase from Anthracophyllum discolor
- 2010
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 80:3, s. 271-278
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Tidskriftsartikel (refereegranskat)abstract
- Manganese peroxidase (MnP) produced by Anthracophyllum discolor, a Chilean white rot fungus, was immobilized on nanoclay obtained from volcanic soil and its ability to degrade polycyclic aromatic hydrocarbons (PAHs) compared with the free enzyme was evaluated. At the same time, nanoclay characterization was performed.Nanoclay characterization by transmission electronic microscopy showed a particle average size smaller than 100nm. The isoelectric points (IEP) of nanoclay and MnP from A. discolor were 7.0 and 3.7, respectively, as determined by micro electrophoresis migration and preparative isoelectric focusing. Results indicated that 75% of the enzyme was immobilized on the nanoclay through physical adsorption. As compared to the free enzyme, immobilized MnP from A. discolor achieved an improved stability to temperature and pH. The activation energy (Ea) value for immobilized MnP (51.9kJmol -1) was higher than that of the free MnP (34.4kJmol -1).The immobilized enzyme was able to degrade pyrene (>86%), anthracene (>65%), alone or in mixture, and to a less extent fluoranthene (<15.2%) and phenanthrene (<8.6%). Compared to free MnP from A. discolor, the enzyme immobilized on nanoclay enhanced the enzymatic transformation of anthracene in soil.Overall results indicate that nanoclay, a carrier of natural origin, is a suitable support material for MnP immobilization. In addition, immobilized MnP shows an increased stability to high temperature, pH and time storage, as well as an enhanced PAHs degradation efficiency in soil. All these characteristics may suggest the possible use of nanoclay-immobilized MnP from A. discolor as a valuable option for in situ bioremediation purposes. © 2010 Elsevier Ltd.
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| 8. |
- Tortella, G.R., et al.
(författare)
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Chlorpyrifos degradation in a biomixture of biobed at different maturity stages
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 88:2, s. 224-228
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Tidskriftsartikel (refereegranskat)abstract
- The biomixture is a principal element controlling the degradation efficacy of the biobed. The maturity of the biomixture used in the biobed affects its overall performance of the biobed, but this is not well studied yet. The aim of this research was to evaluate the effect of using a typical composition of Swedish biomixture at different maturity stages on the degradation of chlorpyrifos. Tests were made using biomixture at three maturity stages: 0d (BC0), 15d (BC15) and 30d (BC30); chlorpyrifos was added to the biobeds at final concentration of 200, 320 and 480mgkg -1. Chlorpyrifos degradation in the biomixture was monitored over time. Formation of TCP (3,5,6-trichloro-2-pyrinidol) was also quantified, and hydrolytic and phenoloxidase activities measured. The biomixture efficiently degraded chlorpyrifos (degradation efficiency >50%) in all the evaluated maturity stages. However, chlorpyrifos degradation decreased with increasing concentrations of the pesticide. TCP formation occurred in all biomixtures, but a major accumulation was observed in BC30. Significant differences were found in both phenoloxidase and hydrolytic activities in the three maturity stages of biomixture evaluated. Also, these two biological activities were affected by the increase in pesticide concentration. In conclusion, our results demonstrated that chlorpyrifos can be degraded efficiently in all the evaluated maturity stages. © 2012 Elsevier Ltd.
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| 9. |
- Bachour, Raougina-Laouisa, et al.
(författare)
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Behavioral effects of citalopram, tramadol, and binary mixture in zebrafish (Danio rerio) larvae
- 2020
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- Pharmaceuticals are emerging as environmentally problematic compounds. As they are often not appropriately removed by sewage treatment plants, pharmaceutical compounds end up in surface water environments worldwide at concentrations in the ng to μg L−1 range. There is a need to further explore single compound and mixture effects using e.g. in vivo test model systems. We have investigated, for the first time, behavioral effects in larval zebrafish (Danio rerio) exposed to a binary mixture of an antidepressant drug (citalopram) and a synthetic opioid (tramadol). Citalopram and tramadol have a similar mode of action (serotonin reuptake inhibition) and are known to produce drug-drug interactional effects resulting in serotonin syndrome (SS) in humans. Zebrafish embryo-larvae were exposed to citalopram, tramadol and 1:1 binary mixture from fertilization until 144 h post fertilization. No effects on heart rate, spontaneous tail coiling, or death/malformations were observed in any treatment at tested concentrations. Behavior (hypoactivity in dark periods) was on the other hand affected, with lowest observed effect concentrations (LOECs) of 373 μg L−1 for citalopram, 320 μg L−1 for tramadol, and 473 μg L−1 for the 1:1 mixture. Behavioral EC50 was calculated to be 471 μg L−1 for citalopram, 411 μg L−1 for tramadol, and 713 μg L−1 for the 1:1 mixture. The results of this study conclude that tramadol and citalopram produce hypoactivity in 144 hpf zebrafish larvae. Further, a 1:1 binary mixture of the two caused the same response, albeit at a higher concentration, possibly due to SS.
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| 10. |
- Campos-Pereira, Hugo, et al.
(författare)
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Effect of pH, surface charge and soil properties on the solid-solution partitioning of perfluoroalkyl substances (PFASs) in a wide range of temperate soils
- 2023
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Ingår i: Chemosphere. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0045-6535 .- 1879-1298. ; 321
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Tidskriftsartikel (refereegranskat)abstract
- The pH-dependent soil-water partitioning of six perfluoroalkyl substances (PFASs) of environmental concern (PFOA, PFDA, PFUnDA, PFHxS, PFOS and FOSA), was investigated for 11 temperate mineral soils and related to soil properties such as organic carbon content (0.2-3%), concentrations of Fe and Al (hydr)oxides, and texture. PFAS sorption was positively related to the perfluorocarbon chain length of the molecule, and inversely related to solution pH for all substances. The negative slope between log Kd and pH became steeper with increasing perfluorocarbon chain length of the PFAS (r2 = 0.75, p <= 0.05). Organic carbon (OC) alone was a poor predictor of the partitioning for all PFASs, except for FOSA (r2 = 0.71), and the OC-normalized PFAS partitioning, as derived from organic soil materials, underestimated PFAS sorption to the soils. Multiple linear regression suggested sorption contributions (p <= 0.05) from OC for perfluorooctane sulfonate (PFOS) and FOSA, and Fe/Al (hydr) oxides for PFOS, FOSA, and perfluorodecanoate (PFDA). FOSA was the only substance under study for which there was a statistically significant correlation between its binding and soil texture (silt + clay). To predict PFAS sorption, the surface net charge of the soil organic matter fraction of all soils was calculated using the Stockholm Humic Model. When calibrated against charge-dependent PFAS sorption to a peat (Oe) material, the derived model significantly underestimated the measured Kd values for 10 out of 11 soils. To conclude, additional
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