Previous studies have identified microplastics (MPs) in commercial table salts but could not exactly address the origin of the MPs because of several limitations. The present study is based on the ...hypothesis that commercial sea salts can act as an indicator of MP pollution in the surrounding environment unless the MPs are filtered out during the manufacturing process. A total of 39 different salt brands produced at geospatially different sites, including 28 sea salt brands from 16 countries/regions on six continents, were investigated. A wide range of MP content (in number of MPs per kg of salt; n/kg) was found: 0–1674 n/kg (excluding one outlier of 13 629 n/kg) in sea salts, 0–148 n/kg in rock salt, and 28–462 n/kg in lake salt. Relatively high MP content was identified in sea salts produced in Asian countries/regions. The abundance of MPs in unrefined sea salts (n = 25) exhibited significant linear correlations with plastic emissions from worldwide rivers (r 2= 0.33; p = 0.003) and with the MP pollution levels in surrounding seawater (r 2= 0.46; p = 0.021) in the published literature. The results indicate that not only is Asia a hot spot of global plastic pollution, as previous studies have suggested, but also that sea salt can be a good indicator of the magnitude of MP pollution in the surrounding marine environment.
Phthalate acid esters (PAEs) are commonly used as plasticizers in numerous plastic applications. Owing to their high leachability, the occurrence of PAEs can be used to trace plastic pollution. The ...northwest Pacific marginal seas, including the East China Sea, are suspected not only to be the area that receives the most plastic waste globally but also transit the waste to the ocean worldwide. To identify the potential sources of PAEs in this area, seawater at different water depths and sediment were investigated. The highest level of di(2-ethylhexyl) phthalate (DEHP), which is primarily used in plastic polymers, was observed in the accumulation zone of plastic debris. Moreover, DEHP exhibited not only the highest levels in the bottom layer of water column but also a significant correlation between bottom water layer and bed sediment, which strongly suggests a continuous flow of PAEs from the seafloor to the seawater column in this area.
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•Horizontal and vertical profiles of phthalates in the north part of East China Sea•Study area was characterized by Korean coast, Yangtze River flow, and TWC intrusion.•Different horizontal and vertical profiles for individual PAE compounds•Highest DEHP levels in bottom water that was positively correlated with sediment•DEHP overcomes the Environmental Risk Levels (ERL) in both seawater and sediment.
•Carbon dose and contact time affected micropollutant adsorption to activated carbon.•Hydrophilics better fit to linear, and hydrophobics better to Freundlich isotherm.•Adsorption of hydrophilic ...micropollutant was significantly affected by pH.•DOM in surface water competed with micropollutants in the adsorption to activated carbon.•Low temperature decreased the adsorption of hydrophobic micropollutants.
In this study, we investigated adsorption characteristics of nine selected micropollutants (six pharmaceuticals, two pesticides, and one endocrine disruptor) in water using an activated carbon. The effects of carbon dosage, contact time, pH, DOM (dissolved organic matter), and temperature on the adsorption removal of micropollutants were examined. Increasing carbon dosage and contact time enhanced the removal of micropollutants. Sorption coefficients of hydrophilic compounds (caffeine, acetaminophen, sulfamethoxazole, and sulfamethazine) fit a linear isotherm and hydrophobic compounds (naproxen, diclofenac, 2, 4-D, triclocarban, and atrazine) fit a Freundlich isotherm. The removal of hydrophobic pollutants and caffeine were independent of pH changes, but acetaminophen, sulfamethazine, and sulfamethoxazole were adsorbed by mainly electrostatic interaction with activated carbon and so were affected by pH. The decrease in adsorption removal in surface water samples was observed and this decrease was more significant for hydrophobic than hydrophilic compounds. The decline in the adsorption capacity in surface water samples is caused by the competitive inhibition of DOM with micropollutants onto activated carbon. Low temperature (5°C) also decreased the adsorption removal of micropollutants, and affected hydrophobic compounds more than hydrophilic compounds. The results obtained in this study can be applied to optimize the adsorption capacities of micropollutants using activated carbon in water treatment process.
Despite intensive use of plastics in agriculture, little is known about the occurrence of microplastics (MPs) in agro-environment. To identify the effect of internal sources and environmental fate on ...MP appearance in farmland, we examined four soil types with different agricultural practices representing either direct application of polyethylene (PE) film—the inside (GS-in) and outside (GS-out) soils of greenhouse and mulch-film use soils (MS)—or rare use of plastics (rice-paddy soils; RS). MP abundance was 10–7630 items kg−1, with the order of GS-in, GS-out, RS, and MS. Besides the highest MP abundance, rare PE-sheet (4% of MPs) and increased MP abundance with sizes decreasing were unique for GS-in, implying the presence of internal sources other than PE-film and continued MP accumulation. Contrarily, in other outside soils high PE-sheet appearance (10–31%) indicated substantial input via fragmentation of applied PE-film (for GS-out and MS) or via surface-runoff (for RS) while drastic decline of small-sized MPs in order of MS > RS > GS-out than expected from steady-state fragmentation implied significant removal of MPs by surface runoff and/or infiltration. Our results suggest the importance of internal sources and environmental fate as significant factors affecting the occurrence of MPs in agricultural soils.
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•We investigated Korean rural farmland soils where PE-film had been intensively used.•Greatest MP levels and lowest PE-sheet ratio were found in GS-in.•Drastic decrease of small-sized MPs was found in order of MS > RS > GS-out > GS-in.•Four soil types reflected different weathering conditions and plastic burden.•Coupled effect of internal sources and environmental fate affects MP occurrence.
There are limited therapeutic options for extensively drug-resistant tuberculosis. In this study from South Korea, linezolid was shown to have some activity in treating resistant tuberculosis; ...however, its use was associated with clinically significant toxicity.
Linezolid (Zyvox, Pfizer) was approved in 2000 for drug-resistant, gram-positive bacterial infections.
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A member of the oxazolidinone antibiotic class, linezolid inhibits protein synthesis by binding the 23S ribosomal RNA (rRNA) portion of the bacterial 50S ribosomal subunit.
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In adults, linezolid is administered at a dose of 600 mg twice daily, with phase 3 and postmarketing trials showing an acceptable side-effect and adverse-event profile during the FDA-approved 28 days of therapy.
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Data on longer-term use are limited, but serious neuropathies (e.g., peripheral and optic neuropathies), myelosuppression, and hyperlactatemia have been observed
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,
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and are considered to be related to the inhibition . . .
Concentrations of perfluorinated acids (PFAs) were measured in various environmental matrices (air, rain, snow, surface runoff water, and lake water) in an urban area, to enable identification of ...sources and pathways of PFAs to urban water bodies. Total PFA concentrations ranged from 8.28 to 16.0 pg/m3 (mean 11.3) in bulk air (sum of vapor and particulate phases), 0.91 to 13.2 ng/L (6.19) in rainwater, 0.91 to 23.9 ng/L (7.98) in snow, 1.11–81.8 ng/L (15.1 ng/L) in surface runoff water (SRW), and 9.49 to 35.9 ng/L (21.8) in lake water. Perfluorooctanoic acid (PFOA) was the predominant compound, accounting for >35% of the total PFA concentrations, in all environmental matrices analyzed. Concentrations and relative compositions of PFAs in SRW were similar to those found for urban lakes. SRW contributes to contamination by PFOA in urban lakes. The measured concentration ratios of FTOH to PFOA in air were 1–2 orders of magnitude lower than the ratios calculated based on an assumption of exclusive atmospheric oxidation of FTOHs. Nevertheless, the mass balance analysis suggested the presence of an unknown input pathway that could contribute to a significant amount of total PFOA loadings to the lake. Flux estimates of PFOA at the air–water interface in the urban lake suggest net volatilization from water.
Mesenchymal stem cells (MSCs) may hold great promise for treating diabetic wounds. However, it is difficult for a clinician to use MSCs because they have not been commercialized. Meanwhile, a new ...commercial drug that contains adipose-derived stem cells (ASCs) has been developed. The purpose of this study was to examine the potential of allogeneic ASC sheets for treating diabetic foot ulcers. Fifty-nine patients with diabetic foot ulcers were randomized to either the ASC treatment group (
= 30) or a control group treated with polyurethane film (
= 29). Either an allogeneic ASC sheet or polyurethane film was applied on diabetic wounds weekly. These wounds were evaluated for a maximum of 12 weeks. Complete wound closure was achieved for 73% in the treatment group and 47% in the control group at week 8. Complete wound closure was achieved for 82% in the treatment group and 53% in the control group at week 12. The Kaplan-Meier median times to complete closure were 28.5 and 63.0 days for the treatment group and the control group, respectively. There were no serious adverse events related to allogeneic ASC treatment. Thus, allogeneic ASCs might be effective and safe to treat diabetic foot ulcers.
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•Analytical procedures causing major data gaps and uncertainty were identified.•Large variation of MPs in literature originated from different analytical methods.•10–600 times ...difference of MP content were found among MP identification methods.•There was a significant correlation between MP content and particle size.•Size-corrected salt consumption values contribute significantly to total MP intake.
Increasing concern of human exposure to microplastics (MPs) necessitates an assessment of the quality of MP data relevant to human exposure. In this literature review for table salt, we addressed the variability and uncertainty of MP data caused by different analytical methods among studies. Additionally, validation experiment was conducted to identify and correct uncertainties related to MP size. When combined without validation, salt data in literature (n = 150) showed a wide range of 0–39800 (1386 ± 5477) MPs kg-1. All procedures, including sample treatment, MP identification, and quality assurance were related to this variability. Most serious variability originated from the MP identification methods associated with minimum cut-off size of targeted/measured MPs and the selection of particles identified. When not corrected by size, MP content differed by 10–600 times among MP identification methods, with greatest value from visual observation, followed by FTIR and Raman methods. Meanwhile, there was a significant correlation—regardless of identification method—between logarithmic mean abundances and minimum cut-off sizes. The size-corrected values showed that adults intake up to 19000 MPs ≥10 μm annually via table salt, compared with 5100 MPs that was estimated from uncorrected mean abundance. Our validation experiment also showed the possibility of serious errors being caused by arbitrary selection of “MP-like particles” in spectroscopic analysis, specifically for smaller-sized particles. A combination of unverified data originated from different methods might have failed to adequately produce reliable human health-relevant results, thereby undermining the ability to quantify human risk.
The present study was designed to characterize the bioaccumulation of organochlorine pesticides (OCPs) in marine organisms (zooplankton,oyster, crab, and goby) on different trophic level. In the ...present study, sedentary bivalve (oyster) showed strong correlations in OCPs levelswith surface sediment in the study area. This indicates the two compartments can be used as alternative for pollution monitoring of OCPseven in narrow scale in space. Bioaccumulation and trophic transfer of OCPs was strongly associated with their hydrophobicity (i.e., KOW).
HCHs with log KOW < 5 did not show any enrichment through food-chain. However, log BAF values of OCPs with log KOW > 5 positionedover the 1:1 lines of log BAF and log KOW of the top predator, indicating the greater fugacities in the higher trophic level and thus the occurrenceof biomagnification via ingestion. Based on trophic transfer factors (TTF), more hydrophobic OCPs with log KOW > 5 were enriched by severalto several ten times in the highest trophic level relative to the lowest trophic level. This finding can be used in the establishment of marineenvironmental water quality criteria by considering biomagnification factors (TTF in this study) of OCPs. KCI Citation Count: 0
The presence and distribution characteristics of microplastics become a big issue due to the adverse effects on marine organisms caused by not only microplastics but any incorporated and/or adsorbed ...pollutants. Distribution of microplastics (50- to 5000-μm size) was determined for three sandy beaches on an isolated island in a high-tidal costal region to elucidate spatial distributions in relation to beach locations. The abundances of microplastics (
n
= 21) measured were 56–285,673 (46,334 ± 71,291) particles/m
2
corresponding to the highest level globally. Out of observed polymer types, expanded polystyrene was overwhelmingly dominant. Although lying toward the estuary of the largest river in the country, the north-side beach contained a 100-fold lower abundance than two south-side beaches that faced southerly wind and currents that were prevalent throughout the study season. In addition, distinct differences between the beaches on either side were also present in terms of size distribution and spatial homogeneity of microplastics on the same beach. Winds and currents are therefore considered to be the driving forces in the distribution of microplastics.
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