Chlorinated paraffins (CPs) are environmental pollutants extensively used in industries. While the use of short-chain chlorinated paraffins (SCCPs) has been restricted since 2017, the use of medium-chain chlorinated paraffins (MCCPs) has risen as their replacement. Due to lipophilic character, it can be expected that CPs enter the cells; however, the in vitro accumulation potential of CPs remains poorly understood. In this study, we aimed to explore the ability of SCCPs and MCCPs to accumulate in fat cells. We utilized an in vitro model of mouse 3T3-L1 preadipocytes and adipocytes. Using gas chromatography coupled with high-resolution mass spectrometry operated in negative chemical ionization mode, we determined the intracellular amounts of CPs. These compounds accumulated at rates of 8.5 ± 0.1 μg/gcells/h for SCCPs and 7.8 ± 0.3 μg/gcells/h for MCCPs when an initial concentration of 120 ng/ml was present in the medium. This rate increased approximately tenfold when the concentration of CPs was raised to 1200 ng/ml. CPs content in adipocytes steadily increased over 5 days, whereas preadipocytes accumulated 15-20 times less CPs. This highlights the importance of cellular lipid content, which was about 12 times higher in adipocytes. Furthermore, we found that the level of chlorine content in the CPs molecules significantly influenced their accumulation. Our results demonstrate that MCCPs exhibit a similar accumulation potential to SCCPs, with lipid content playing a crucial role. As with SCCPs, restrictions on the use of MCCPs in industry should be considered to mitigate their environmental and health impacts.
- MeSH
- 3T3-L1 Cells * MeSH
- Hydrocarbons, Chlorinated * metabolism toxicity MeSH
- Halogenation * MeSH
- Environmental Pollutants toxicity metabolism MeSH
- Lipid Metabolism drug effects MeSH
- Mice MeSH
- Paraffin * MeSH
- Gas Chromatography-Mass Spectrometry MeSH
- Adipocytes * metabolism drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Electronic waste (e-waste) poses significant environmental and health risks in Thailand due to both domestic production and international imports. A notable portion of this waste is processed in small-scale, community-based workshops, often located in poorer regions, where safety regulations are improperly enforced or entirely ignored. This study focuses on the Kalasin province in Northern Thailand, a region with numerous such workshops, where no comprehensive analysis of exposure to polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) has been conducted. The study's objective was to quantify these toxic substances in environmental and biological samples to assess its contamination and human health risks. Environmental samples, including soil, dust, sediment, ash, eggs, crabs, snails, fish, and rice, were collected from e-waste processing sites and compared with control areas. Blood samples from e-waste workers and a control group were also analysed. Gas chromatography coupled with mass spectrometry operated in negative ion chemical ionization (GC-NCI-MS) was used to quantify PBDEs and DP isomers. Results showed significantly higher concentrations of these toxic compounds in e-waste sites compared to control areas. E-waste workers also had elevated levels of these substances in their blood, suggesting exposure through contaminated dust and food. These findings underscore the severe environmental contamination and health risks associated with improper e-waste management, highlighting the urgent need for regulatory measures and improved recycling practices to safeguard both environmental and public health.
- MeSH
- Hydrocarbons, Chlorinated * analysis blood MeSH
- Electronic Waste * analysis MeSH
- Halogenated Diphenyl Ethers * analysis toxicity blood MeSH
- Risk Assessment MeSH
- Environmental Pollutants analysis blood MeSH
- Humans MeSH
- Environmental Monitoring methods MeSH
- Polycyclic Compounds * analysis MeSH
- Dust analysis MeSH
- Occupational Exposure analysis MeSH
- Recycling * MeSH
- Environmental Exposure adverse effects analysis MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Thailand MeSH
As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants of three age groups: (i) 3,576 children aged 6-12 years, (ii) 3,117 teenagers aged 12-18 years and (iii) 4,102 young adults aged 20-39 years. The participants were recruited between 2014 and 2021 in 11-12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability and will give leverage to national policy makers for the implementation of targeted measures.
- MeSH
- Acrylamides MeSH
- Arsenic * analysis MeSH
- Biomarkers MeSH
- Biological Monitoring MeSH
- Child MeSH
- Fluorocarbons * analysis MeSH
- Cadmium analysis MeSH
- Environmental Pollutants * analysis MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Pesticides * analysis MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Persistent halogenated compounds (PHC) are of concern for human and environmental health. Persistent Organic Pollutants (POPs) are regulated by international treaties, but alternative compounds such as novel brominated flame retardants (NBFRs) and Dechlorane Plus (DP) are not-yet they are increasingly used. There are no data on PHCs in coral reef biota from tropical islands in the western Indian Ocean (WIO). For this assessment, three hard coral genera, two soft coral genera, and ember parrotfish (Scarus rubroviolaceus) were collected from the remote Rodrigues, Agalega, and St. Brandon's Atoll (Republic of Mauritius) in the Mascarene Basin of the WIO. Five compounds - Pentabromotoluene (PBT), γ-HCH, p,p'-DDE, HCB, and BDE-47- were quantifiable in all samples. Hard coral consistently contained the lowest concentrations of PHCs, except for NBFRs. The presence of BDE-47 suggests long-range aerial transport. We quantified DP, currently a candidate POP, in coral reef biota. PBT was measured in all samples also suggests long-range transport. Because the hard coral, soft coral, and fish had differing concentrations and patterns of PHCs, future surveys should stratify sampling accordingly. Agalega and St. Brandon's Atoll can be considered as locations to monitor changes in background concentrations of pollutants due to their remoteness.
- MeSH
- Halogenated Diphenyl Ethers analysis MeSH
- Anthozoa * MeSH
- Coral Reefs MeSH
- Humans MeSH
- Environmental Monitoring MeSH
- Islands MeSH
- Flame Retardants * analysis MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Indian Ocean MeSH
- Islands MeSH
Over the past two decades, the use of nanoscale zero-valent iron (nZVI) has emerged as a standard method of contaminated groundwater remediation. The effectiveness of this method depends on key intrinsic hydrogeological parameters, which can affect both reactivity of the nanoparticles and their migration in the aquifer. In the case of low hydraulic permeability, the migration of nanoparticles is limited, which negatively influences remediation. An application of nZVI reinforced with a DC electric field led to a significant increase in the efficiency of remediation, as demonstrated by long-term monitoring at a former industrial site in Horice (Czech Republic). For the method testing, a 12 × 9 m polygon was defined around well IS4, where the original contamination was predominantly composed of DCE (7300 μg/l), and with a total concentration of chlorinated ethenes of 8880 μg/l. During the first stage of the activities, 49 kg of nZVI was injected and monitored for two years. Subsequently, the electrodes were installed, and for three years, the synergistic action of nZVI within an applied DC field was monitored. Based on 32 monitoring campaigns performed over the six years, the combined method was compared with an application of the only nZVI in technical, environmental and economic terms. Technically, the method requires annual reinstallation of anodes as a result of their oxidative disintegration. Environmentally, the method provides significantly improved chlorinated ethane reduction, remediation of low permeable zones, and extended efficiency. Economically, the method is five times cheaper when compared to the nZVI used alone.
- MeSH
- Water Pollutants, Chemical analysis chemistry MeSH
- Ethylenes analysis chemistry MeSH
- Halogenation MeSH
- Metal Nanoparticles chemistry MeSH
- Groundwater MeSH
- Environmental Restoration and Remediation * MeSH
- Iron MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Halogenated phenols, such as 2,4-dichlorophenol (2,4-DCP) and 4-bromophenol (4-BP) are pollutants generated by a various industrial sectors like chemical, dye, paper bleaching, pharmaceuticals or in an agriculture as pesticides. The use of Horseradish peroxidase (HRP) in the halogenated phenols treatment has already been mentioned, but it is not well understood how the different phenolic substrates can bind in the peroxidase active site nor how these specific interactions can influence in the bioremediation potential. In this work, different removal efficiencies were obtained for phenolic compounds investigated using HRP as catalyst (93.87 and 59.19% to 4BP and 2,4 DCP, respectively). Thus, to rationalize this result based on the interactions of phenols with active center of HRP, we combine computational and experimental methodologies. The theoretical approaches utilized include density functional theory (DFT) calculations, docking simulation and quantum mechanics/molecular mechanics (QM/MM) technique. Michaelis Menten constant (Km) obtained through experimental methodologies were 2.3 and 0.95 mM to 2,4-DCP and 4-BP, respectively, while the specificity constant (Kcat/Km) found was 1.44 mM-1 s-1 and 0.62 mM-1 s-1 for 4-BP and 2,4-DCP, respectively. The experimental parameters appointed to the highest affinity of HRP to 4-BP. According to the molecular docking calculations, both ligands have shown stabilizing intermolecular interaction energies within the HRP active site, however, the 4-BP showed more stabilizing interaction energy (-53.00 kcal mol-1) than 2,4-dichlorophenol (-49.23 kcal mol-1). Besides that, oxidative mechanism of 4-BP and 2,4-DCP was investigated by the hybrid QM/MM approach. This study showed that the lowest activation energy values for transition states investigated were obtained for 4-BP. Therefore, by theoretical approach, the compound 4-BP showed the more stabilizing interaction and activation energy values related to the interaction within the enzyme and the oxidative reaction mechanism, respectively, which corroborates with experimental parameters obtained. The combination between experimental and theoretical approaches was essential to understand how the degradation potential of the HRP enzyme depends on the interactions between substrate and the active center cavity of the enzyme.
Plastic waste of electrical and electronic equipment (WEEE) can contain polybrominated diphenyl ethers (PBDEs) that have been used as fire retardants for a long time. PBDEs were listed in the Stockholm Convention as persistent organic pollutants, so PBDE-containing plastic waste should be separated and disposed of in an ecologically sound manner. In the article, the results of bromine and PBDE content in plastic samples of WEEE collected in Belarus are presented. The screening method for bromine identification and HRGC/HRMS for PBDE identification were applied. It is shown that bromine is present in 43% of the 111 studied samples. Most often, Br-containing plastic was found in CRT monitor, CRT TVs and LCD monitor (about 50%), printers (35%), and LCD TVs (25%). PBDEs were revealed in 12 Br-containing samples, representing TVs, monitors, and printers. The sum of ∑10PBDEs varied from 6.6 to 21,000 μg/kg. BDE-209 dominated in 9 samples (75% of cases); BDE-183, in two; and BDE-47 and BDE-99, in one sample. Based on the low content of PBDEs in the plastic, year of equipment production, and year of restriction of PBDEs applied in the countries-manufacturers, it was concluded that the presence of PBDEs in plastic is a consequence of contaminated waste recycling. Despite the relatively low concentrations of PBDEs (below the limit values established by the Stockholm and Basel conventions for POP wastes), further research is necessary with an extension of the list of analyzed types of equipment and identification of other brominated flame retardants.
- MeSH
- Electronic Waste analysis MeSH
- Halogenated Diphenyl Ethers analysis MeSH
- Environmental Monitoring MeSH
- Plastics MeSH
- Flame Retardants analysis MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Republic of Belarus MeSH
Desfluran je halogenované inhalační celkové anestetikum s nízkou rozpustností v krvi i tkáních a asi pětinovou anestetickou potencí, ve srovnání s isofluranem. Jeho nízká rozpustnost dává předpoklady k rychlému nástupu anestézie a její velmi dobré řiditelnosti. Vzhledem k jeho dráždivosti jej nelze používat k inhalačnímu úvodu v dětské anestézii. Vzdor této nepříjemné vlastnosti však nese řadu vlastností ideálního inhalačního anestetika, jako je chemická stabilita molekuly, nízká rozpustnost, zanedbatelný metabolismus a tím i minimální potenciál k hepatotoxicitě a nefrotoxicitě. Těmito fyzikálními vlastnostmi a farmakokinetickými charakteristikami představuje velmi hodnotné inhalační anestetikum nejen v ambulantní anestézii.
Desflurane is a halogenated inhalation general anaesthetic agent with low solubility in blood and body tissues, and approximately one-fifih the potency of isoflurane. The low solubility of desflurane facilitates a rapid induction of anaesthesia and precise control of the depth of anaesthesia. Transient airway irritant effects are the most common adverse events during induction of anaesthesia with desflurane; therefore, this agent is not recommended for induction of anaesthesia in paediatric patients. Overall it embodies many of the desirable features of an ideal agent, which include stability to chemical degradation, low solubility in blood and body tissues, negligible metabolism and low potential for hepatorenal toxicity. These favourable physical and pharmacokinetic characteristics should present desflurane as a valuable inhalation anaesthetic agent for the maintenance of general anaesthesia in ambulatory surgery as well as in nonambulatory surgical procedures.
ISCO using activated sodium persulphate is a widely used technology for treating chlorinated solvent source zones. In sensitive areas, however, high groundwater sulphate concentrations following treatment may be a drawback. In situ biogeochemical transformation, a technology that degrades contaminants via reduced iron minerals formed by microbial activity, offers a potential solution for such sites, the bioreduction of sulphate and production of iron sulphides that abiotically degrade chlorinated ethenes acting as a secondary technology following ISCO. This study assesses this approach in the field using hydrochemical and molecular tools, solid phase analysis and geochemical modelling. Following a neutralisation and bioaugmentation, favourable conditions for iron- and sulphate-reducers were created, resulting in a remarkable increase in their relative abundance. The abundance of dechlorinating bacteria (Dehalococcoides mccartyi, Dehalobacter sp. and Desulfitobacterium spp.) remained low throughout this process. The activity of iron- and sulphate-reducers was further stimulated through application of magnetite plus starch and microiron plus starch, resulting in an increase in ferrous iron concentration (from
- MeSH
- Water Pollutants, Chemical analysis metabolism MeSH
- Chlorine metabolism MeSH
- Chloroflexi metabolism MeSH
- Water Purification methods MeSH
- Desulfitobacterium metabolism MeSH
- Ethylenes metabolism MeSH
- Halogenation MeSH
- Oxidation-Reduction MeSH
- Peptococcaceae metabolism MeSH
- Groundwater analysis chemistry microbiology MeSH
- Environmental Restoration and Remediation methods MeSH
- Solvents metabolism MeSH
- Sulfates metabolism MeSH
- Sodium Compounds MeSH
- Tetrachloroethylene analysis metabolism MeSH
- Trichloroethylene analysis metabolism MeSH
- Iron metabolism MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Haloalkane dehalogenases (HLDs) convert halogenated aliphatic pollutants to less toxic compounds by a hydrolytic mechanism. Owing to their broad substrate specificity and high enantioselectivity, haloalkane dehalogenases can function as biosensors to detect toxic compounds in the environment or can be used for the production of optically pure compounds. Here, the structural analysis of the haloalkane dehalogenase DpcA isolated from the psychrophilic bacterium Psychrobacter cryohalolentis K5 is presented at the atomic resolution of 1.05 Å. This enzyme exhibits a low temperature optimum, making it attractive for environmental applications such as biosensing at the subsurface environment, where the temperature typically does not exceed 25°C. The structure revealed that DpcA possesses the shortest access tunnel and one of the most widely open main tunnels among structural homologs of the HLD-I subfamily. Comparative analysis revealed major differences in the region of the α4 helix of the cap domain, which is one of the key determinants of the anatomy of the tunnels. The crystal structure of DpcA will contribute to better understanding of the structure-function relationships of cold-adapted enzymes.
- MeSH
- Bacterial Proteins chemistry genetics metabolism MeSH
- Escherichia coli genetics metabolism MeSH
- Gene Expression MeSH
- Genetic Vectors chemistry metabolism MeSH
- Hydrocarbons, Halogenated chemistry metabolism MeSH
- Hydrolases chemistry genetics metabolism MeSH
- Protein Interaction Domains and Motifs MeSH
- Cloning, Molecular MeSH
- Protein Conformation, alpha-Helical MeSH
- Protein Conformation, beta-Strand MeSH
- Crystallography, X-Ray MeSH
- Cold Temperature MeSH
- Psychrobacter chemistry enzymology MeSH
- Recombinant Fusion Proteins chemistry genetics metabolism MeSH
- Amino Acid Sequence MeSH
- Molecular Docking Simulation MeSH
- Structural Homology, Protein MeSH
- Substrate Specificity MeSH
- Thermodynamics MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- Publication type
- Journal Article MeSH
