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Toxics
Volume 9
Issue 2
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Toxics, Volume 9, Issue 2 (February 2021) – 25 articles

Cover Story (view full-size image): The use of neonicotinoid insecticides has been steadily increasing in many countries, despite bans on their use by the European Union and Canada. Among the main concerns have been their impacts on non-target invertebrates, including molluscs. Increasing evidence from studies on terrestrial, freshwater and marine molluscs have demonstrated the detrimental effects of concentrations of neonicotinoids that have been detected in soil, food and water. The accumulation of neonicotinoid residues in the flesh of molluscs can also cause the accidental exposure of other organisms higher in the food chain, including humans. Further studies are required using all commercially available neonicotinoids, across all life stages of a broad range of ecologically and economically valuable molluscs, to comprehensively understand the magnitude of impacts from ongoing neonicotinoid use. View this paper
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19 pages, 1034 KiB  
Review
Microplastics in the Marine Environment: Sources, Fates, Impacts and Microbial Degradation
by Huirong Yang, Guanglong Chen and Jun Wang
Toxics 2021, 9(2), 41; https://doi.org/10.3390/toxics9020041 - 22 Feb 2021
Cited by 94 | Viewed by 14996
Abstract
The serious global microplastic pollution has attracted public concern in recent years. Microplastics are widely distributed in various environments and their pollution is already ubiquitous in the ocean system, which contributes to exponential concern in the past decade and different research areas. Due [...] Read more.
The serious global microplastic pollution has attracted public concern in recent years. Microplastics are widely distributed in various environments and their pollution is already ubiquitous in the ocean system, which contributes to exponential concern in the past decade and different research areas. Due to their tiny size coupled with the various microbial communities in aquatic habitats capable of accumulating organic pollutants, abundant literature is available for assessing the negative impact of MPs on the physiology of marine organisms and eventually on the human health. This study summarizes the current literature on MPs in the marine environment to obtain a better knowledge about MP contamination. This review contains three sections: (1) sources and fates of MPs in the marine environment, (2) impacts of MPs on marine organisms, and (3) bacteria for the degradation of marine MPs. Some measures and efforts must be taken to solve the environmental problems caused by microplastics. The knowledge in this review will provide background information for marine microplastics studies and management strategies in future. Full article
(This article belongs to the Special Issue Microplastics in Aquatic Environments: Occurrence, Distribution and Effects)
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Figure 1

Figure 1
<p>The basic characteristics of microplastic about size, type, shape, source and fate.</p> Full article ">Figure 2
<p>The record count and the percentage of total publications in the top 40 research areas related to the assessment of the microplastic effects on organisms and bacterial degradation over time. Source: Web of Science; Period: 1944–2020; Total Publications: 4685; h-index: 162; Average citations per item: 29.31; Sum of Times Cited: 137,315 (without self-citations: 53,749); Citing articles: 32,830 (without self-citations: 29,560). TS = (microplastic * OR micro-plastic * OR plastic particle * OR plastic particulate OR plastic debris OR plastisphere * OR microplastic pollution *) AND (source * OR fate * OR occurrence * OR distribute * OR influence * OR impact * OR affect OR risk * OR effect * OR exposure * OR exposed OR colonize OR colonization OR bacteria * OR germ * OR microbiological OR microorganisms OR microbial OR microbiota OR macrobiotic OR biotechnological OR degrade * OR degradation * OR biodegradation * OR biodegrade * OR organisms * OR creature * OR biota * OR habitat *) AND (marine * OR ocean * OR sea * OR seawater * OR beach * OR shore * OR coast * OR seacoast * OR seaboard *).</p> Full article ">
19 pages, 1937 KiB  
Article
Salinity Changes the Dynamics of Pyrethroid Toxicity in Terms of Behavioral Effects on Newly Hatched Delta Smelt Larvae
by Amelie Segarra, Florian Mauduit, Nermeen R. Amer, Felix Biefel, Michelle L. Hladik, Richard E. Connon and Susanne M. Brander
Toxics 2021, 9(2), 40; https://doi.org/10.3390/toxics9020040 - 20 Feb 2021
Cited by 17 | Viewed by 3922
Abstract
Salinity can interact with organic compounds and modulate their toxicity. Studies have shown that the fraction of pyrethroid insecticides in the aqueous phase increases with increasing salinity, potentially increasing the risk of exposure for aquatic organisms at higher salinities. In the San Francisco [...] Read more.
Salinity can interact with organic compounds and modulate their toxicity. Studies have shown that the fraction of pyrethroid insecticides in the aqueous phase increases with increasing salinity, potentially increasing the risk of exposure for aquatic organisms at higher salinities. In the San Francisco Bay Delta (SFBD) estuary, pyrethroid concentrations increase during the rainy season, coinciding with the spawning season of Delta Smelt (Hypomesus transpacificus), an endangered, endemic fish. Furthermore, salinity intrusion in the SFBD is exacerbated by global climate change, which may change the dynamics of pyrethroid toxicity on aquatic animals. Therefore, examining the effect of salinity on the sublethal toxicity of pyrethroids is essential for risk assessments, especially during the early life stages of estuarine fishes. To address this, we investigated behavioral effects of permethrin and bifenthrin at three environmentally relevant concentrations across a salinity gradient (0.5, 2 and 6 PSU) on Delta Smelt yolk-sac larvae. Our results suggest that environmentally relevant concentrations of pyrethroids can perturb Delta Smelt larvae behavior even at the lowest concentrations (<1 ng/L) and that salinity can change the dynamic of pyrethroid toxicity in terms of behavioral effects, especially for bifenthrin, where salinity was positively correlated with anti-thigmotaxis at each concentration. Full article
(This article belongs to the Special Issue Impacts of Agrochemicals on Aquatic Ecosystems: Assessing Responses across Biological Scales)
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Experimental design for yolk-sac Delta Smelt larvae exposure to permethrin and bifenthrin insecticides. (<b>A</b>) Multiple stressor exposures across 3 salinities x 4 insecticide concentrations. (<b>B</b>) Exposure timeline, showing behavioral assessment conducted following 96 h exposure.</p> Full article ">Figure 2
<p>Delta Smelt yolk-sac larvae behavioral response after 96 h exposure to permethrin across a salinity gradient (0.5, 2 or 6 PSU). Mean Delta Smelt swimming activity in (<b>A</b>) dark and (<b>B</b>) light cycles periods following permethrin exposure. Plotted circles represent activity over 10 min dark (x3) or 5 min light (x2) photoperiods. Data are representative of the calculated Z-scores normalized to controls, which are presented on the 0 axis in each figure. Behavioral parameters include total distance moved (cm), velocity (cm/s), anti-thigmotaxis (or anti-thig.: time spent in the center zone), and duration of movement across three speed levels, freezing (&lt;0.5 cm/s), cruising (0.5 to 2.0 cm/s) and bursting (&gt;2cm/s). Arrows represent a significant increase (↑), or decrease (↓) in activity in comparison to control. <span class="html-italic">n</span> = 20 larvae used in behavioral observations for each treatment (insecticide concentrations /salinity). * <span class="html-italic">p</span> &lt; 0.05; ** <span class="html-italic">p</span> &lt; 0.005; *** <span class="html-italic">p</span> &lt; 0.0005, Kruskal–Wallis test followed by Dunn’s test, comparing all concentrations to control within each cycle per salinity.</p> Full article ">Figure 3
<p>Delta Smelt yolk-sac larvae behavioral response after 96 h exposure to bifenthrin across a salinity gradient (0.5, 2 or 6 PSU). Mean Delta Smelt swimming activity in (<b>A</b>) dark and (<b>B</b>) light cycles periods following bifenthrin exposure. Plotted circles represents activity over 10 min dark (x3) or 5 min light (x2) photoperiods. Data are representative of the calculated Z-scores normalized to controls, which are presented on the 0 axis in each figure. Behavioral parameters include total distance moved (cm), velocity (cm/s), anti-thigmotaxis (or anti-thig.: time spent in the center zone), and duration of each movement across three speed levels, freezing (&lt;0.5 cm/s), cruising (0.5 to 2.0 cm/s) and bursting (&gt;2cm/s). Arrows represent a significant increase (↑), or decrease (↓) in activity in comparison to control. <span class="html-italic">n</span> = 20 larvae used in behavioral observations for each treatment (insecticide concentrations /salinity). * <span class="html-italic">p</span> &lt; 0.05; ** <span class="html-italic">p</span> &lt;0.005; *** <span class="html-italic">p</span> &lt; 0.0005, Kruskal–Wallis test followed by Dunn’s test, comparing all concentrations to control within each cycle per salinity.</p> Full article ">Figure 4
<p>Effect of salinity on Delta Smelt yolk-sac larvae behavior exposed with permethrin. (<b>A</b>) Total distance moved response of larvae under the dark period and (<b>B</b>) thigmotaxic behavior (edge/wall preference) of Delta Smelt larvae at four permethrin concentrations (0, 1, 10 and 100 ng/L) over dark and light cycles. Letters indicate a significant difference between groups (Dunn’s test, <span class="html-italic">p</span> &lt; 0.05), and error bars represent the S.E.M.</p> Full article ">Figure 5
<p>Effect of salinity on Delta Smelt yolk-sac larvae behavior exposed with bifenthrin. <b>(</b><b>A</b>) Total distance moved response of larvae under the dark period and (<b>B</b>) thigmotaxic behavior (edge/wall preference) of Delta Smelt larvae at four bifenthrin concentrations (0, 0.1, 1 and 10 ng/L) over dark and light cycles, and (<b>C</b>) example locomotion trace of individual larval Delta Smelt performing thigmotaxis (wall/edge preference) in the control, to a lesser extent, in the exposed larvae. (orange: edge zone; yellow: in center zone of the well) in the dark period at 6 PSU. In the bar graphs, different letters indicate a significant difference between groups (Dunn’s test, <span class="html-italic">p</span> &lt; 0.05), and error bars represent the S.E.M.</p> Full article ">
14 pages, 1361 KiB  
Article
Levels of Mercury, Methylmercury and Selenium in Fish: Insights into Children Food Safety
by Grazia Barone, Arianna Storelli, Daniela Meleleo, Angela Dambrosio, Rita Garofalo, Antonio Busco and Maria Maddalena Storelli
Toxics 2021, 9(2), 39; https://doi.org/10.3390/toxics9020039 - 20 Feb 2021
Cited by 45 | Viewed by 5140
Abstract
Total mercury (THg), methylmercury (MeHg), and selenium (Se) concentrations were measured in various commercially important fish species. The benefit–risk binomial associated with these chemicals was assessed in children through the probability of exceeding the provisional tolerable weekly intakes (PTWIs) of the contaminants and [...] Read more.
Total mercury (THg), methylmercury (MeHg), and selenium (Se) concentrations were measured in various commercially important fish species. The benefit–risk binomial associated with these chemicals was assessed in children through the probability of exceeding the provisional tolerable weekly intakes (PTWIs) of the contaminants and the Se recommended dietary allowance (RDA). The Se:Hg molar ratios, selenium health benefit values (HBVSe), and monthly consumption rate limits (CRmm) for each species were also calculated. THg and Se were analyzed by atomic absorption spectrophotometer (Shimadzu, Milan, Italy), while MeHg was determined by Trace Ultra gas chromatograph connected with a PolarisQ MS (Thermo Fisher Scientific, Waltham, MA, USA). None of the analyzed fish had Hg levels above the European Community regulatory limits, while most large predators had MeHg levels over the threshold concentration set by US EPA. The estimated weekly intakes of THg and MeHg exceeded in many cases the PTWIs and the Se estimated daily intakes were provided from 0.71% to 2.75% of the RDA. Se:Hg molar ratios above 1 and positive HBVSe index suggested that Se in fish could be enough to alleviate the potential toxic effect of Hg. However, high-risk groups as children should consume fish in moderation because a large consumption pattern, especially of swordfish and tunas, might be of concern for health. Full article
(This article belongs to the Section Exposome Analysis and Risk Assessment)
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Concentrations of total mercury (THg) and methylmercury (MeHg) in fish muscle tissue in comparison to international guidelines. Dashed gray lines: maximum concentration of THg (0.5 and 1 µg g<sup>−1</sup> wet wt.) [<a href="#B42-toxics-09-00039" class="html-bibr">42</a>]; black line: maximum concentration of MeHg (0.3 µg g<sup>−1</sup> wet wt.) [<a href="#B43-toxics-09-00039" class="html-bibr">43</a>].</p> Full article ">Figure 2
<p>Se:Hg molar ratios and Se health benefit values (HBV<sub>Se</sub>) of the studied fish species. Dark line: Se:Hg molar ratio &gt; 1.</p> Full article ">Figure 3
<p>Maximum allowable fish consumption rate in meals/month (CR<sub>mm</sub>) for children without adverse health effects.</p> Full article ">
12 pages, 2025 KiB  
Article
Eupatilin Inhibits Reactive Oxygen Species Generation via Akt/NF-κB/MAPK Signaling Pathways in Particulate Matter-Exposed Human Bronchial Epithelial Cells
by Dong Chang Lee, Jeong-Min Oh, Hyunsu Choi, Sung Won Kim, Soo Whan Kim, Byung Guk Kim, Jin Hee Cho, Joohyung Lee and Ji-Sun Kim
Toxics 2021, 9(2), 38; https://doi.org/10.3390/toxics9020038 - 18 Feb 2021
Cited by 8 | Viewed by 2590
Abstract
Background: Eupatilin is an active flavon extracted from the Artemisia species and has properties such as antioxidant, anti-inflammatory, and anti-cancer. We examined the effect of eupatilin using fine particulate matter (FPM) and human bronchial epithelial cell line (BEAS-2B) to confirm the potential of [...] Read more.
Background: Eupatilin is an active flavon extracted from the Artemisia species and has properties such as antioxidant, anti-inflammatory, and anti-cancer. We examined the effect of eupatilin using fine particulate matter (FPM) and human bronchial epithelial cell line (BEAS-2B) to confirm the potential of eupatilin as a therapeutic agent for respiratory diseases caused by FPM. Methods: Reactive oxygen species (ROS) levels were checked by flow cytometry to identify if FPM and eupatilin affect ROS production. Western blotting was performed to identify the mechanism of action of eupatilin in FPM-exposed BEAS-2B cells. Results: When cells were exposed to FPM above 12.5 μg/mL concentration for 24 h, ROS production increased significantly compared to the control. When eupatilin was added to cells exposed to FPM, the ROS level decreased proportionally with the eupatilin dose. The phosphorylation of Akt, NF-κB p65, and p38 MAPK induced by FPM was significantly reduced by eupatilin, respectively. Conclusion: FPM cause respiratory disease by producing ROS in bronchial epithelial cells. Eupatilin has been shown to inhibit ROS production through altering signaling pathways. The ROS inhibiting property of eupatilin can be exploited in FPM induced respiratory disorders. Full article
(This article belongs to the Special Issue Molecular Basis of Air-Pollution-Induced Disease Risk)
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Figure 1

Figure 1
<p>Effects of FPM and eupatilin on BEAS-2B cell viability. (<b>A</b>) BEAS-2B cell viability after FPM treatment for 24 h. (<b>B</b>) BEAS-2B cell viability after treatment with eupatilin for 24 h. (<b>C</b>) BEAS-2B cell viability after treatment with eupatilin and FPM for 24 h. Three independent experiments were conducted. Each value in the graph presented as the mean ± SEM. ** <span class="html-italic">p</span> &lt; 0.01 and *** <span class="html-italic">p</span> &lt; 0.001 vs. control untreated group; # <span class="html-italic">p</span> &lt; 0.05 and ## <span class="html-italic">p</span> &lt; 0.01 vs. 12.5 μg/mL FPM. FPM, fine particulate matter; WST, water-soluble tetrazolium salts.</p> Full article ">Figure 2
<p>ROS product in BEAS-2B cells treated with FPM or eupatilin as measured by flow cytometry. (<b>A</b>) Dose-dependent ROS product in BEAS-2B cells exposed to FPM. (<b>B</b>) ROS production depending on the dose of eupatilin in BEAS-2B cells (<b>C</b>) Eupatilin decreased FPM induced ROS generation in BEAS-2B cells. Three independent experiments were conducted. Data are presented as the mean ± SEM. * <span class="html-italic">p</span> &lt; 0.05, and *** <span class="html-italic">p</span> &lt; 0.001 vs. control untreated group; # <span class="html-italic">p</span> &lt; 0.05 and ## <span class="html-italic">p</span> &lt; 0.01 vs. 12.5 μg/mL of FPM. ROS: reactive oxygen species; FPM: fine particulate matter; SEM: standard error of the mean.</p> Full article ">Figure 2 Cont.
<p>ROS product in BEAS-2B cells treated with FPM or eupatilin as measured by flow cytometry. (<b>A</b>) Dose-dependent ROS product in BEAS-2B cells exposed to FPM. (<b>B</b>) ROS production depending on the dose of eupatilin in BEAS-2B cells (<b>C</b>) Eupatilin decreased FPM induced ROS generation in BEAS-2B cells. Three independent experiments were conducted. Data are presented as the mean ± SEM. * <span class="html-italic">p</span> &lt; 0.05, and *** <span class="html-italic">p</span> &lt; 0.001 vs. control untreated group; # <span class="html-italic">p</span> &lt; 0.05 and ## <span class="html-italic">p</span> &lt; 0.01 vs. 12.5 μg/mL of FPM. ROS: reactive oxygen species; FPM: fine particulate matter; SEM: standard error of the mean.</p> Full article ">Figure 3
<p>Phosphorylation of Akt, p65, and p38 following the exposure of BEAS-2B cells to FPM (12.5 μg/mL) with or without eupatilin (10 nM). (<b>A</b>) Time-dependent phosphorylation of BEAS-2B cells induced by FPM. (<b>B</b>) Density ratio of p-Akt to Akt. (<b>C</b>) Density ratio of p-p65 to p65. (<b>D</b>) Density ratio of p-p38 to p38. (<b>E</b>) p-Akt, total Akt, p-p65, total p65, p-p38, and total p38 protein expression levels were determined by Western blot. (<b>F</b>) Density ratio of p-Akt to Akt. (<b>G</b>) Density ratios of p-p65 to p65. (<b>H</b>) Density ratios of p-p38 to p38. Three independent experiments were conducted. Data are presented as the mean ± SEM. * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01 and *** <span class="html-italic">p</span> &lt; 0.001 vs. control untreated group; # <span class="html-italic">p</span> &lt; 0.05 vs. 12.5 μg/mL of FPM. FPM: fine particulate matter; Akt: protein kinase B; GAPDH: Glyceraldehyde-3-Phosphate Dehydrogenase; SEM: standard error of the mean.</p> Full article ">Figure 4
<p>Effects of eupatilin, MK-2206 (Akt inhibitor), and BAY11-7082 (NF-kB inhibitor) on the FPM induced activation of Akt, p65, and p38 in BEAS-2B cells. The BEAS-2B cells were stimulated with FPM (12.5 μg/mL) with or without eupatilin (10 nM), MK-2206 (10 μM), and BAY11-7082 (10 μM of). (<b>A</b>) p-Akt, total Akt, p-p65, total p65, p-p38, and total p38 protein expression levels were determined by Western blot. (<b>B</b>) Density ratio of p-Akt to Akt. (<b>C</b>) Density ratios of p-p65 to p65. (<b>D</b>) Density ratios of p-p38 to p38. Three independent experiments were conducted. Each value of the graph represents the mean ± SEM. * <span class="html-italic">p</span> &lt; 0.05 and *** <span class="html-italic">p</span> &lt; 0.001 vs. 0 μg/mL of FPM and 0 nM of eupatilin; ## <span class="html-italic">p</span> &lt; 0.01 and ### <span class="html-italic">p</span> &lt; 0.001 vs. 12.5 μg/mL of FPM. FPM: fine particulate matter; Akt: protein kinase B; GAPDH: Glyceraldehyde-3-Phosphate Dehydrogenase; SEM: standard error of the mean; MK-2206: Akt inhibitor; BAY11-7082: p65 inhibitor.</p> Full article ">Figure 5
<p>Effects of eupatilin, MK-2206 (Akt inhibitor), and BAY11-7082 (NF-κB inhibitor) on ROS products in BEAS-2B cells. The cells were stimulated with FPM (12.5 μg/mL) with or without eupatilin (10 nM), MK-2206 (10 μM), or BAY11-7082 (10 μM). Three independent experiments were conducted. Data are presented as the mean ± SEM. *** <span class="html-italic">p</span> &lt; 0.001 vs. control untreated group; # <span class="html-italic">p</span> &lt; 0.05 and ## <span class="html-italic">p</span> &lt; 0.01 vs. 12.5 μg/mL FPM. Akt, protein kinase B; MK-2206, Akt inhibitor; BAY11-7082, p65 inhibitor; FPM, fine particulate matter.</p> Full article ">
22 pages, 13288 KiB  
Article
Sequential SEM-EDS, PLM, and MRS Microanalysis of Individual Atmospheric Particles: A Useful Tool for Assigning Emission Sources
by Francisco E. Longoria-Rodríguez, Lucy T. González, Yasmany Mancilla, Karim Acuña-Askar, Jesús Alejandro Arizpe-Zapata, Jessica González, Oxana V. Kharissova and Alberto Mendoza
Toxics 2021, 9(2), 37; https://doi.org/10.3390/toxics9020037 - 18 Feb 2021
Cited by 9 | Viewed by 3277
Abstract
In this work, the particulate matter (PM) from three different monitoring stations in the Monterrey Metropolitan Area in Mexico were investigated for their compositional, morphological, and optical properties. The main aim of the research was to decipher the different sources of the particles. [...] Read more.
In this work, the particulate matter (PM) from three different monitoring stations in the Monterrey Metropolitan Area in Mexico were investigated for their compositional, morphological, and optical properties. The main aim of the research was to decipher the different sources of the particles. The methodology involved the ex situ sequential analysis of individual particles by three analytical techniques: scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), polarized light microscopy (PLM), and micro-Raman spectroscopy (MRS). The microanalysis was performed on samples of total suspended particles. Different morphologies were observed for particles rich in the same element, including prismatic, spherical, spheroidal, and irregular morphologies. The sequential microanalysis by SEM-EDS/PLM/MRS revealed that Fe-rich particles with spherical and irregular morphologies were derived from anthopogenic sources, such as emissions from the metallurgical industry and the wear of automobile parts, respectively. In contrast, Fe-rich particles with prismatic morphologies were associated with natural sources. In relation to carbon (C), the methodology was able to distinguish between the C-rich particles that came from different anthopogenic sources—such as the burning of fossil fuels, biomass, or charcoal—and the metallurgical industry. The optical properties of the Si-rich particles depended, to a greater extent, on their chemical composition than on their morphology, which made it possible to quickly and accurately differentiate aluminosilicates from quartz. The methodology demonstrated in this study was useful for performing the speciation of the particles rich in different elements. This differentiation helped to assign their possible emission sources. Full article
(This article belongs to the Special Issue Analytical Chemistry of Air Pollution)
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Figure 1

Figure 1
<p>Monitoring stations in the Monterrey Metropolitan Area (MMA) where particulate matter (PM) sampling was conducted. Source: Google Earth</p> Full article ">Figure 2
<p>Description of the methodology used in the sequential microanalysis.</p> Full article ">Figure 3
<p>Chemical mapping of the particulate matter: we observed that the most abundant elements are Si, Ca, Al, and O for the Obispado (<b>A</b>) and Santa Catarina (<b>B</b>) areas, while for Cadereyta (<b>C</b>) they are Si, Al, and O.</p> Full article ">Figure 4
<p>Micrographs and optical mappings with parallel and crossed polarizers obtained for the total suspended particle (TSP) collected in: (<b>A</b>) Obispado, (<b>B</b>) Santa Catarina, and (<b>C</b>) Cadereyta.</p> Full article ">Figure 5
<p>Sequential microanalysis (SMA) of a Si-rich particle showing a spheroidal morphology. (<b>A</b>) Electronic micrograph. (<b>B</b>) Polarized light micrograph with parallel polarizer, (<b>C</b>) crossed polarizer, (<b>D</b>) Elemental analysis by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and (<b>E</b>) Raman spectrum.</p> Full article ">Figure 6
<p>(<b>A</b>) Electron micrograph of a Fe-rich particle with spheroidal morphology and corrugated surface associated with anthopogenic sources. Optical micrograph with polarizer in (<b>B</b>) parallel and (<b>C</b>) crossed. (<b>D</b>) Elemental analysis by SEM-EDS and (<b>E</b>) Raman spectrum where the D and G bands of the carbonaceous material that coated the particle are observed.</p> Full article ">Figure 7
<p>SMA of a spheroidal C-rich particle with a smooth surface. (<b>A</b>) SEM electron micrograph. Polarized light microscopy (PLM) micrograph with polarizer in (<b>B</b>) parallel and (<b>C</b>) crossed. (<b>D</b>) Elemental analysis by SEM-EDS and (<b>E</b>) Raman spectrum.</p> Full article ">Figure 8
<p>Si-rich particle conglomerate studied by SMA. (<b>A</b>) SEM electron micrograph. Typical third-order colors of silicates observed in optical micrographs using (<b>B</b>) parallel polarizer and (<b>C</b>) crossed. (<b>D</b>) Elemental composition by SEM-EDS and (<b>E</b>) Characteristic bands of silicates due to Raman modes present in these minerals.</p> Full article ">Figure 9
<p>A high level of anisotropy was shown by a C-rich particle with irregular morphology when analyzed by SMA. (<b>A</b>) Electron micrograph. Optical micrographs with polarized light, using (<b>B</b>) the parallel and (<b>C</b>) crossed nicols. (<b>D</b>) Elemental composition by SEM-EDS and (<b>E</b>) Raman spectrum of the particle.</p> Full article ">Figure 10
<p>SMA study of a Fe-rich particle with irregular morphology associated with the wear of automobile parts. (<b>A</b>) SEM electron micrograph. Optical micrographs reveal the change in (<b>B</b>) natural color and (<b>C</b>) interference due to anisotropy in the particle microstructure. (<b>D</b>) Elemental analysis by SEM-EDS. (<b>E</b>) Raman modes of the hematite obtained by MRS.</p> Full article ">Figure 11
<p>Prismatic Si-rich particles studied by SMA. (<b>A</b>) Electron micrograph. The analysis by PLM demonstrates the high level of isotropy in the particle because there is no variation in its (<b>B</b>) natural color and (<b>C</b>) interference. (<b>D</b>) Elemental analysis by SEM-EDS. (<b>E</b>) Raman spectrum showing bands associated with quartz.</p> Full article ">Figure 12
<p>(<b>A</b>) Electron micrograph of a rhombic C-rich particle. Optical micrographs of polarized light with the nicols in: (<b>B</b>) parallel and (<b>C</b>) crossed. (<b>D</b>) Elemental analysis by SEM-EDS. (<b>E</b>) Raman spectrum.</p> Full article ">Figure 13
<p>(<b>A</b>) Electron micrograph of a prismatic particle associated with CaCO3 from soil resuspension. (<b>B</b>) Natural color and (<b>C</b>) interference obtained by PLM. (<b>D</b>) Elemental analysis by SEM-EDS. (<b>E</b>) Bands related to the Raman modes of calcite.</p> Full article ">Figure 14
<p>SMA study of a hematite particle possibly related to the crustal material of the MMA. (<b>A</b>) SEM electron micrograph. (<b>B</b>) Natural color and (<b>C</b>) interference typical of hematite mineral. (<b>D</b>) Elemental analysis by SEM-EDS. (<b>E</b>) Characteristic Raman spectrum of hematite by MRS.</p> Full article ">
9 pages, 1760 KiB  
Brief Report
Toxic Blood Hydrogen Cyanide Concentration as a Vital Sign of a Deceased Room Fire Victim—Case Report
by Daniel Tabian, Gabi Drochioiu, Simona Irina Damian, Nona Girlescu, Oana Toma Gradinaru, Sebastian Ionut Toma and Diana Bulgaru Iliescu
Toxics 2021, 9(2), 36; https://doi.org/10.3390/toxics9020036 - 16 Feb 2021
Cited by 9 | Viewed by 5372
Abstract
Carbon monoxide (CO) and hydrogen cyanide (HCN) are two common toxic products of combustion. HCN concentrations of fire victims are not routinely determined in most legal medicine services in Romania. We present the case of a room fire victim in which we evaluated [...] Read more.
Carbon monoxide (CO) and hydrogen cyanide (HCN) are two common toxic products of combustion. HCN concentrations of fire victims are not routinely determined in most legal medicine services in Romania. We present the case of a room fire victim in which we evaluated the concentrations of HCN and carboxyhemoglobin (COHb), their contribution to the mechanism of death, and the possibility that HCN concentration can be interpreted as vital sign. COHb was determined by spectrophotometry. HCN was spectrophotometrically determined with ninhydrin in postmortem blood samples after its removal with 20% phosphoric acid and uptake into a solution of potassium carbonate. The presence of ethyl alcohol was determined by gas chromatography. The COHb concentration was 6.15%, while the blood HCN concentration was 1.043 µg × mL−1 and the total HCN was 1.904 µg × ml−1. A blood alcohol content of 4.36 g‰ and a urine alcohol content of 5.88 g‰ were also found. Although the fire produced a considerable amount of soot, and there were signs of inhalation of soot particles, the COHb level cannot be interpreted as a vital sign. Toxic concentrations of HCN and total HCN can be interpreted as a vital sign and indicates a contributive effect of HCN in the mechanism of death. Full article
(This article belongs to the Section Toxicology)
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<p>Laryngopharynx after dorsal dissection: The presence of deposited soot. Laryngeal edema and the effect of heat on tissues.</p> Full article ">Figure 2
<p>Trachea and the openings to the main bronchi after dorsal dissection: The presence of deposited soot.</p> Full article ">Figure 3
<p>Kinetics of the reaction of cyanide with the ninhydrin reagent. Here, HCN—hydrogen cyanide removed first from blood with phosphoric acid; KMnO<sub>4</sub>—hydrogen cyanide resulting from the oxidation of thiocyanates in blood with potassium permanganate; tot KMnO<sub>4</sub>—total HCN resulting from one step treatment of 1 mL blood sample with potassium permanganate and phosphoric acid; 1.08 γ—1.08 µg × mL<sup>−1</sup> KCN control solution; 0.81 γ—0.81 µg × mL<sup>−1</sup> KCN control solution.</p> Full article ">
16 pages, 1747 KiB  
Article
Ecological and Health Risks Assessment of Potentially Toxic Metals and Metalloids Contaminants: A Case Study of Agricultural Soils in Qatar
by Mohammed Alsafran, Kamal Usman, Hareb Al Jabri and Muhammad Rizwan
Toxics 2021, 9(2), 35; https://doi.org/10.3390/toxics9020035 - 12 Feb 2021
Cited by 32 | Viewed by 4193
Abstract
In recent years, Qatar has witnessed exponential growth in the human population, urbanization, and increased anthropogenic activities, including agriculture. Potentially toxic environmental contaminants, including metals and metalloids, are commonly found in emerging economies. At high concentrations, elements such as As, Cr, and Ni [...] Read more.
In recent years, Qatar has witnessed exponential growth in the human population, urbanization, and increased anthropogenic activities, including agriculture. Potentially toxic environmental contaminants, including metals and metalloids, are commonly found in emerging economies. At high concentrations, elements such as As, Cr, and Ni can be hazardous and may lead to various health problems in humans, including cancer. The current study measured As, Cd, Cr, Cu, Ni, Pb, V, and Zn concentrations in agricultural soils. Pollution levels and potential negative impacts on human and environmental health were determined using the United States Environmental Protection Agency (USEPA) standard methodologies. According to the study’s findings, the studied element concentrations descended in the following order: Zn > Cr > V > Ni > As > Cu > Pb > Cd. Of these, As (27.6 mg/kg), Cr (85.7 mg/kg), Ni (61.9 mg/kg), and Zn (92.3 mg/kg) concentrations were higher than average world background levels. Each of these elements also had an enrichment factor (EF > 1), indicating their anthropogenic origin. The combined pollution load index (PLI > 1) and geo-accumulation index (Igeo) range values of −0.2–2.5 further indicated that the soil was up to 58% polluted. However, the ecological risk factor (Er ≤ 40.6) and potential ecological risk index (PERI = 79.6) suggested low ecological risk. A human health risk evaluation showed that only As, with a hazard index (HI) of 1.3, posed a noncarcinogenic risk to infants. Additionally, As, Cr, and Ni, with total carcinogenic risk (TCR) values of 1.18 × 10−4 and 2.06 × 10−4 for adults and children, respectively, proved carcinogenic to both age groups. The elements’ carcinogenic risk (CR) potential descended in the following order: Ni > As > Cr. Additionally, for both adults and children, oral ingestion is the most likely exposure pathway. Our findings support the need for closer monitoring of potentially toxic metals and metalloids levels in cultivated soils and farm produce in Qatar. Reducing the elements’ bioavailability in soil and developing innovative remediation technologies is needed to limit potential risks to human health. Further studies on As, Cr, and Ni gastrointestinal bioaccessibilities are needed to fully understand the effects after long-term exposure and the cancer-causing potential of these elements over a lifetime. Full article
(This article belongs to the Section Exposome Analysis and Risk Assessment)
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<p>Sampling locations.</p> Full article ">Figure 2
<p>(<b>A</b>) Metals enrichment factors (EF); (<b>B</b>) geo-accumulation index (Igeo).</p> Full article ">Figure 3
<p>(<b>A</b>) Metals contamination factors (CF); (<b>B</b>) ecological risk factors (Er); (<b>C</b>) pollution load index (PLI) and potential ecological risk (PERI).</p> Full article ">Figure 3 Cont.
<p>(<b>A</b>) Metals contamination factors (CF); (<b>B</b>) ecological risk factors (Er); (<b>C</b>) pollution load index (PLI) and potential ecological risk (PERI).</p> Full article ">Figure 4
<p>The metals HI: (<b>A</b>) adult; (<b>B</b>) child.</p> Full article ">Figure 5
<p>The metals total carcinogenic risks (TCR): (<b>A</b>) adult; (<b>B</b>) child.</p> Full article ">
11 pages, 833 KiB  
Article
Occurrence of Bisphenols and Benzophenone UV Filters in White-Tailed Eagles (Haliaeetus albicilla) from Smøla, Norway
by Bernat Oró-Nolla, Silvia Lacorte, Kristine Vike-Jonas, Susana V. Gonzalez, Torgeir Nygård, Alexandros G. Asimakopoulos and Veerle L.B. Jaspers
Toxics 2021, 9(2), 34; https://doi.org/10.3390/toxics9020034 - 9 Feb 2021
Cited by 7 | Viewed by 4796
Abstract
There is a growing concern about the occurrence of bisphenols and benzophenone UV filters in natural ecosystems, while data are limited regarding their actual occurrence in wildlife species, especially in raptors. In this study, concentrations of bisphenol and benzophenone UV filter analogues were [...] Read more.
There is a growing concern about the occurrence of bisphenols and benzophenone UV filters in natural ecosystems, while data are limited regarding their actual occurrence in wildlife species, especially in raptors. In this study, concentrations of bisphenol and benzophenone UV filter analogues were determined in liver tissue samples (n = 38) from white-tailed eagles (Haliaeetus albicilla) that were found dead in Smøla (2006–2018), which is a Norwegian municipality that holds one of the densest breeding populations of white-tailed eagles in Europe. Bisphenol AF (BPAF; a fluorinated analogue) was the most ubiquitous contaminant since it was detected in 32 liver samples at concentrations ranging from 1.08 to 6.68 ng/g wet weight (w.w.), followed by bisphenol A (BPA, mean 10.4 ng/g w.w.), benzophenone-1 (BzP-1, mean 3.24 ng/g w.w.), and 4-hydroxybenzophenone (4-OH-BzP, mean 0.62 ng/g w.w.). The concentrations found in livers suggested that white-tailed eagles potentially accumulate bisphenols and benzophenone UV filters, which raises concern, as these plastic and personal care product-related emerging contaminants can show endocrine-disrupting properties. The high detection frequency of the fluorinated BPAF warrants further attention as other fluorinated compounds have proven to be extremely persistent and potentially harmful to wildlife. Full article
(This article belongs to the Special Issue Wildlife Toxicology: An Update on Contaminant Exposure and Effects)
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<p>Location of Smøla island in Norway [<a href="#B36-toxics-09-00034" class="html-bibr">36</a>]; right corner: Focus on the Smøla wind farm; showing the web of turbines located on the island [<a href="#B34-toxics-09-00034" class="html-bibr">34</a>].</p> Full article ">
14 pages, 1097 KiB  
Article
Association between Urinary Phthalate Metabolites and Markers of Endothelial Dysfunction in Adolescents and Young Adults
by Po-Ching Chu, Charlene Wu and Ta-Chen Su
Toxics 2021, 9(2), 33; https://doi.org/10.3390/toxics9020033 - 6 Feb 2021
Cited by 12 | Viewed by 2633
Abstract
Endothelial function is crucial in the pathogenesis of circulatory and cardiovascular toxicity; epidemiologic research investigating the association between phthalate exposure and endothelial dysfunction remains limited. We examined the associations between exposures to specific phthalates (di-2-ethylhexyl phthalate, DEHP; di-n-butyl phthalate, DnBP) and circulating endothelial [...] Read more.
Endothelial function is crucial in the pathogenesis of circulatory and cardiovascular toxicity; epidemiologic research investigating the association between phthalate exposure and endothelial dysfunction remains limited. We examined the associations between exposures to specific phthalates (di-2-ethylhexyl phthalate, DEHP; di-n-butyl phthalate, DnBP) and circulating endothelial and platelet microparticles (EMPs and PMPs) in adolescents and young adults. Of the 697 participants recruited, anthropometric measurements and health-related behaviors relevant to cardiovascular risks were collected and assessed. Urine and serum were collected and analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) and flow cytometry. Multiple linear regression indicated that increases in urinary concentrations of ΣDEHP and MnBP (mono-n-butyl phthalate), across quartiles, were positively associated with serum EMPs level (p for trend <0.001 and <0.001; β = 0.798 and 0.007; standard error = 0.189 and 0.001, respectively). Moreover, female and overweight subjects had higher MnBP, and males were more vulnerable to DnBP exposure compared to females. In conclusion, our results demonstrate a dose-response relationship between exposures to phthalates (ΣDEHP and MnBP) and microparticle formation (EMPs and PMPs) in adolescents and young adults. The findings indicate that exposures to phthalates of both low and high-molecular weight are positively associated with microparticle production, and might contribute to endothelial dysfunction; such damage might manifest in the form of atherosclerotic-related vascular diseases. Future in vivo and in vitro studies are warranted to elucidate whether a causal relationship exists between phthalate exposure and EMPs and PMPs. Full article
(This article belongs to the Special Issue Plasticizer Exposure: Harmful Impact on Human Health)
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<p>Flow chart of the study population recruitment.</p> Full article ">Figure 2
<p>Geometric mean values and 95% confidence intervals of natural log-transformed EMPs and PMPs according to quartile concentrations of urinary ΣDEHP and MnBP <sup>a</sup> in multiple linear regression model <sup>b</sup>. (<b>a</b>) ΣDEHP and Ln-EMPs, (<b>b</b>) ΣDEHP and Ln-PMPs, (<b>c</b>) MnBP and Ln-EMPs, (<b>d</b>) MnBP and Ln-PMPs. DEHP: di-2-ethylhexyl phthalate; MnBP: mono-n-butyl phthalate; EMP: endothelial microparticles; PMP: platelet microparticles. <sup>a</sup> ΣDEHP as μmol/g creatinine, and others as μg/g creatinine. EMPs and PMPs as counts/μL. <sup>b</sup> p for trend analysis—value was modeled according to median value of each quartile of each phthalates metabolites, and was adjusted for age, gender, body mass index, total cholesterol, hypertension, diabetes, smoking, alcohol consumption, physical activity, and household income.</p> Full article ">
12 pages, 2176 KiB  
Article
Investigation on Combined Inhalation Exposure Scenarios to Biocidal Mixtures: Biocidal and Household Chemical Products in South Korea
by Sunmi Kim, Myungwon Seo, Minju Na and Jongwoon Kim
Toxics 2021, 9(2), 32; https://doi.org/10.3390/toxics9020032 - 4 Feb 2021
Cited by 14 | Viewed by 4634
Abstract
Global regulations of biocides have been continuously enhanced for protecting human health and the environment from potentially harmful biocidal products. Such regulations consider the combined toxicity caused by mixture components in a biocidal product of which approval and authorization are to be enhanced. [...] Read more.
Global regulations of biocides have been continuously enhanced for protecting human health and the environment from potentially harmful biocidal products. Such regulations consider the combined toxicity caused by mixture components in a biocidal product of which approval and authorization are to be enhanced. Although the combined exposure scenarios of components in mixtures are firstly needed to conduct the mixture risk assessment, systematic combined exposure scenarios are still lacking. In this study, combined inhalation exposure scenarios of biocides in household chemical and biocidal products marketed in South Korea were investigated based on the European Union (EU) and Korean chemical product databases and various data sources integration. The information of 1058 biocidal products and 675 household chemical products that are likely to cause inhalation exposure with two or more biocides was collected, and mixture combination patterns were investigated. Binary mixtures occupied 72% in biocidal products. The most frequently appearing binary mixture was phthalthrin and d-phenothrin. Based on the frequency of use, we suggested a priority list of biocide mixture combinations which need to be firstly evaluated for identifying their combined toxicity for the mixture risk assessment. This study highlights that the derived combined inhalation exposure scenarios can support and facilitate further studies on priority settings for mixture risk assessment and management of potentially inhalable biocides. Full article
(This article belongs to the Section Exposome Analysis and Risk Assessment)
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Graphical abstract
Full article ">Figure 1
<p>Distribution of the specific product category (<b>a</b>) biocidal products; (<b>b</b>) household chemical products which have biocidal active substances in the combined inhalation exposure scenario data of biocides in South Korea investigated in this study.</p> Full article ">Figure 1 Cont.
<p>Distribution of the specific product category (<b>a</b>) biocidal products; (<b>b</b>) household chemical products which have biocidal active substances in the combined inhalation exposure scenario data of biocides in South Korea investigated in this study.</p> Full article ">Figure 2
<p>A part of the network visualization of chemical combinations in biocidal and household chemical products. Lines connect ingredients contained in the same product, and color-focused with larger size vertices means more abundantly used chemicals. The numbers in circles represent the CAS registry number of chemicals. Five compounds that have the high node’s degree in this part are shown as follows: 64-17-5 (ethanol), 2634-33-5 (BIT), 78-70-6 (linalool), 5989-27-5 (D-Limonene), and 122-99-6 (2-phenoxyethanol).</p> Full article ">Figure 3
<p>Distribution of the number of biocides in the mixture combinations investigated in the combined inhalation exposure scenarios data of biocides in South Korea (<b>a</b>) biocidal products; (<b>b</b>) household chemical products.</p> Full article ">Figure 3 Cont.
<p>Distribution of the number of biocides in the mixture combinations investigated in the combined inhalation exposure scenarios data of biocides in South Korea (<b>a</b>) biocidal products; (<b>b</b>) household chemical products.</p> Full article ">
9 pages, 287 KiB  
Article
First Assessment of Plasticizers in Marine Coastal Litter-Feeder Fauna in the Mediterranean Sea
by Sabrina Lo Brutto, Davide Iaciofano, Vincenzo Lo Turco, Angela Giorgia Potortì, Rossana Rando, Vincenzo Arizza and Vita Di Stefano
Toxics 2021, 9(2), 31; https://doi.org/10.3390/toxics9020031 - 4 Feb 2021
Cited by 20 | Viewed by 4298
Abstract
Micro and nanoplastics are harmful to marine life due to their high level of fragmentation and resistance to degradation. Over the past two decades, marine coastal sediment has shown an increasing amount of microplastics being a sort of trap for debris wastes or [...] Read more.
Micro and nanoplastics are harmful to marine life due to their high level of fragmentation and resistance to degradation. Over the past two decades, marine coastal sediment has shown an increasing amount of microplastics being a sort of trap for debris wastes or chemicals. In such an environment some species may be successful candidates to be used as monitors of environmental and health hazards and can be considered a mirror of threats of natural habitats. Such species play a key role in the food web of littoral systems since they are litter-feeders, and are prey for fishes or higher trophic level species. A preliminary investigation was conducted on five species of small-sized amphipod crustaceans, with the aim to understand if such an animal group may reflect the risk to ecosystems health in the central Mediterranean area, recently investigated for seawater and fish contamination. This study intended to gather data related to the accumulation of plasticizers in such coast dwelling fauna. In order to detect the possible presence of xenobiotics in amphipods, six analytes were scored (phthalic acid esters and non-phthalate plasticizers), identified and quantified by the gas chromatography mass spectrometry (GC-MS) method. The results showed that among all the monitored contaminants, DEP and DiBP represented the most abundant compounds in the selected amphipods. The amphipod crustaceans analyzed were a good tool to detect and monitor plasticizers, and further studies of these invertebrates will help in developing a more comprehensive knowledge of chemicals spreading over a geographical area. The results are herein presented as a starting point to develop baseline data of plasticizer pollution in the Mediterranean Sea. Full article
(This article belongs to the Special Issue Environmental and Biological Monitoring: Analytical Methods and Assessment)
13 pages, 3509 KiB  
Article
Disturbance in Mammalian Cognition Caused by Accumulation of Silver in Brain
by Anna A. Antsiferova, Marina Yu. Kopaeva, Vyacheslav N. Kochkin, Pavel K. Kashkarov and Mikhail V. Kovalchuk
Toxics 2021, 9(2), 30; https://doi.org/10.3390/toxics9020030 - 3 Feb 2021
Cited by 12 | Viewed by 2781
Abstract
The influence of daily prolonged administration of silver nanoparticles on the cognitive functions of a model mammal was studied. The accumulation of silver in the whole brain and the hippocampus, cerebellum, cortex and residual brain tissue of the mouse was investigated by highly [...] Read more.
The influence of daily prolonged administration of silver nanoparticles on the cognitive functions of a model mammal was studied. The accumulation of silver in the whole brain and the hippocampus, cerebellum, cortex and residual brain tissue of the mouse was investigated by highly precise and representative neutron activation analysis, and histological studies were conducted. Here, we show that long-term memory impairments were caused by the accumulation of silver nanoparticles in the brain and its subregions, such as the hippocampus, cerebellum and cortex, in a step-like manner by disturbance of hippocampal cell integrity. Three different approaches allowed us to observe this phenomenon and discover the reasons it occurred. Full article
(This article belongs to the Collection Environmental and Health Risks of Nanotechnology)
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<p>Apparatus for the neutron activation analysis (NAA). Aluminium case (1) on the left, experimental samples in plastic tubes (2) and paper gaskets with reference samples (3) on the right.</p> Full article ">Figure 2
<p>TEM image of AG-NPs used in the experiment. It can be seen that the nanoparticles are relatively dispersed and are of quasi-spherical shape.</p> Full article ">Figure 3
<p>Accumulation of silver in the brain. Dependence of the mass of silver in the brain on the period of administration of Ag-NPs obtained by NAA. Silver monotonically accumulated in the brain over time. Data are represented as the mean ± SEM.</p> Full article ">Figure 4
<p>Accumulation of silver in subregions of the brain: (<b>a</b>) hippocampus, (<b>b</b>) cerebellum, (<b>c</b>) cortex, (<b>d</b>) remaining brain tissue. Dependencies of the concentration of silver (in ng/g of brain tissue) in the regions of the brain on the period of administration obtained by NAA. A step-like increase in the silver concentration can be seen at 120 days of administration for the hippocampus, cerebellum and cortex and at 180 days for the residual brain tissue. Data are represented as the mean ± SEM.</p> Full article ">Figure 4 Cont.
<p>Accumulation of silver in subregions of the brain: (<b>a</b>) hippocampus, (<b>b</b>) cerebellum, (<b>c</b>) cortex, (<b>d</b>) remaining brain tissue. Dependencies of the concentration of silver (in ng/g of brain tissue) in the regions of the brain on the period of administration obtained by NAA. A step-like increase in the silver concentration can be seen at 120 days of administration for the hippocampus, cerebellum and cortex and at 180 days for the residual brain tissue. Data are represented as the mean ± SEM.</p> Full article ">Figure 5
<p>Comparison of hippocampal structure of the mice. Representative Nissl-stained brain tissue sections from (<b>A</b>,<b>B</b>) the control group and Ag-NP-exposed mice in the (<b>C</b>,<b>D</b>) ‘120 days’ and (<b>E</b>,<b>F</b>) ‘180 days’ groups. Visible changes can be seen in the CA2 region of the hippocampus of Ag-NP-exposed mice relative to that of the control mice (arrows). Scale bars: 500 μm (<b>A</b>,<b>C</b>,<b>E</b>), 200 μm (<b>B</b>,<b>D</b>,<b>F</b>).</p> Full article ">Figure 6
<p>Impairment of long-term contextual fear memory in Ag-NP-exposed mice in the ‘180 days’ group tested 24 h after training. The daily exposure dose was 50 µg per animal. The level of freezing was significantly lower among mice in the ‘FC’ Ag-NP-exposed group than among the ‘FC’ control group. This effect was not observed in the other groups. Data are represented as the median ± interquartile range. * <span class="html-italic">p</span> &lt; 0.05; nonparametric Mann-Whitney test (<span class="html-italic">n</span> = 6–8 animals per group).</p> Full article ">Scheme 1
<p>Schematic diagram of the general route of the experiment with the mammals.</p> Full article ">
13 pages, 2557 KiB  
Article
Local Toxicity of Biocides after Direct and Aerosol Exposure on the Human Skin Epidermis and Airway Tissue Models
by Nahyun Lee, Dae Yong Jang, Do Hyeon Lee, Haengdueng Jeong, Ki Taek Nam, Dal-Woong Choi and Kyung-Min Lim
Toxics 2021, 9(2), 29; https://doi.org/10.3390/toxics9020029 - 3 Feb 2021
Cited by 9 | Viewed by 3191
Abstract
Biocides are commonly used as spray- or trigger-type formulations, thus dermal and respiratory exposure to biocide aerosol is unavoidable. However, little is known about the impact of aerosolization on the local toxicity of biocides on the skin or the airway. We compared the [...] Read more.
Biocides are commonly used as spray- or trigger-type formulations, thus dermal and respiratory exposure to biocide aerosol is unavoidable. However, little is known about the impact of aerosolization on the local toxicity of biocides on the skin or the airway. We compared the local toxicity of biocides after direct or aerosol exposure on reconstructed human skin epidermis and upper airway models. Three biocides, 1,2-benzisothiazol-3(2H)-one (BIT), 2-phenoxyethanol (PE), and 2-phenylphenol (OPP), most widely used in the market were selected. When the biocide was treated in aerosols, toxicity to the skin epidermis and upper airway tissue became significantly attenuated compared with the direct application as determined by the higher tissue viabilities. This was further confirmed in histological examination, wherein the tissue damages were less pronounced. LC-MS/MS and GC/MS analysis revealed that concentrations of biocides decreased during aerosolization. Importantly, the toxicity of biocides treated in 3 μm (median mass aerodynamic diameter (MMAD)) aerosols was stronger than that of 5 μm aerosol, suggesting that the aerosol particle size may affect biocide toxicity. Collectively, we demonstrated that aerosolization could affect the local toxicity of biocides on the skin epidermis and the upper airway. Full article
(This article belongs to the Special Issue Environmental and Human Health Risk Assessment of Emerging Contaminants)
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<p>Aerosol exposure system and time course in the mass deposition of aerosolized biocides: (<b>a</b>) Schematic representation and (<b>b</b>) photo of aerosol application. Aerosol exposure occurs in the middle of the chamber. The tissue inserts are housed in a tissue tray prefilled with culture media during exposure. (<b>c</b>) The time course in the mass deposition of aerosolized biocides. Data show mean mass deposited during exposure time (mean ± SD, <span class="html-italic">n</span> = 4). Biocides at other concentrations also showed similar trends (data not shown).</p> Full article ">Figure 2
<p>Toxicity of biocides on KeraSkin<sup>TM</sup> after direct or aerosol application. (<b>a</b>) Tissue viability of KeraSkin<sup>TM</sup> tissue measured with ((3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide) (MTT) assay at 48 h after the exposure to biocides through direct (grey bars) or aerosol application (blue bars) for 30 min. Values are mean ± SD (<span class="html-italic">n</span> = 3). NC; negative control (1% DMSO in PBS), PC; positive control (5% sodium dodecyl sulfate); BIT; 1,2-Benzothiazol-3-one, PE; 2-Phenoxyethanol, OPP; 2-Phenylphenol. * <span class="html-italic">p</span> &lt; 0.05 or ** <span class="html-italic">p</span> &lt; 0.01 by Student <span class="html-italic">t</span>-test. (<b>b</b>) Representative histological photographs of the treated tissues after hematoxylin-eosin (H&amp;E) staining. Scale bar is 50 µm. E, V, and S stand for erosion (detachment of epithelial cells), vacuolation (formation of vacuoles in cytosol), and spongiosis (intercellular edema), which was indicated on BIT 5000 μg/mL photo.</p> Full article ">Figure 3
<p>Toxicity of biocides on SoluAirway<sup>TM</sup> after direct or aerosol application: (<b>a</b>) Tissue viability of SoluAirway<sup>TM</sup> tissue measured with MTT assay after the exposure to biocides through direct (grey bars) or aerosol application (blue bars) for 3 h. Values are mean ± SD (<span class="html-italic">n</span> &gt; 2) or ½difference (<span class="html-italic">n</span> = 2). NC; negative control (phosphate-buffered saline, PBS), PC; positive control (14.7 mg/mL formaldehyde) by Student <span class="html-italic">t</span>-test. (<b>b</b>) Representative histological photographs of the treated tissues after H&amp;E staining. Scale bar is 20 µm. Cell debris below the transmembrane shall be ignored since they were generated during tissue section.</p> Full article ">Figure 4
<p>Toxicity of BIT and PE on SoluAirway<sup>TM</sup> after the application of 3 µm or 5 μm aerosol: (<b>a</b>) Tissue viability of SoluAirway<sup>TM</sup> tissue measured with MTT assay after the exposure to aerosols of BIT and PE with 5 µm MMAD (blue) or 3 µm MMAD (light blue) for 3 h. Values are mean ± SD (<span class="html-italic">n</span> &gt; 2) or ½difference (<span class="html-italic">n</span> = 2). ** <span class="html-italic">p</span> &lt; 0.01 by Student <span class="html-italic">t</span>-test (<b>b</b>) Representative histological photographs of the treated tissues after H&amp;E staining. Scale bar is 20 µm.</p> Full article ">
11 pages, 6413 KiB  
Article
Effects of Sub-Lethal Doses of Selenium Nanoparticles on the Health Status of Rats
by Lenka Urbankova, Sylvie Skalickova, Magdalena Pribilova, Andrea Ridoskova, Pavlina Pelcova, Jiri Skladanka and Pavel Horky
Toxics 2021, 9(2), 28; https://doi.org/10.3390/toxics9020028 - 3 Feb 2021
Cited by 23 | Viewed by 3911
Abstract
Selenium nanoparticles (SeNPs) are fast becoming a key instrument in several applications such as medicine or nutrition. Questions have been raised about the safety of their use. Male rats were fed for 28 days on a monodiet containing 0.5, 1.5, 3.0 and 5.0 [...] Read more.
Selenium nanoparticles (SeNPs) are fast becoming a key instrument in several applications such as medicine or nutrition. Questions have been raised about the safety of their use. Male rats were fed for 28 days on a monodiet containing 0.5, 1.5, 3.0 and 5.0 mg Se/kg. Se content in blood and liver, liver panel tests, blood glucose, total antioxidant capacity (TAC), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were analysed. Liver and duodenum were subjected to histopathology examination. The weight gain of rats showed no differences between tested groups. Se content in blood was higher in all treated groups compared to the control group. The liver concentration of Se in the treated groups varied in the range from 222 to 238 ng/g. No differences were observed in the activity of AST (aspartate aminotransferase), ALP (alkaline phosphatase) and TAS (total antioxidant status). A significant decrease in ALT activity compared to the control group was observed in the treated groups. GPx activity varied from 80 to 88 U/mL through tested groups. SOD activity in liver was decreased in the SeNP-treated group with 5 mg Se/kg (929 ± 103 U/mL). Histopathological examination showed damage to the liver parenchyma and intestinal epithelium in a dose-dependent manner. This study suggests that short-term SeNP supplementation can be safe and beneficial in Se deficiency or specific treatment. Full article
(This article belongs to the Collection Environmental and Health Risks of Nanotechnology)
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Full article ">Figure 1
<p>(<b>A</b>) SEM documentation and (<b>B</b>) size distribution of SeNPs.</p> Full article ">Figure 2
<p>Selenium content obtained by AAS in (<b>A</b>) blood and (<b>B</b>) liver tissue. Rats were fed on a monodiet containing wheat and the different dose of selenium nanoparticles (0.5, 1.5, 3 and 5 mg Se/kg). Results are compared with the control group (C) of rats fed on a monodiet containing 0.03 mg Se/kg. * Mean values were significantly different (<span class="html-italic">p</span> &lt; 0.05). Details of measurement are described in the Materials and Method section.</p> Full article ">Figure 3
<p>Biochemical profile of liver of control group (C) and after SeNP dietary intake determined from the blood. The activity of liver enzymes: (<b>A</b>) AST (<b>B</b>) ALP, (<b>C</b>) ALT. The concentration of (<b>D</b>) Total protein, (<b>E</b>) ALB and (<b>F</b>) Glucose. * Mean values were significantly different (<b><span class="html-italic">p</span></b>  &lt;  0.05). Details of measurement are described in the Materials and Method section.</p> Full article ">Figure 4
<p>Antioxidant status of rats in the control group (C) and SeNP-enriched diet. (<b>A</b>) Total antioxidant status in blood, (<b>B</b>) GPx in blood and (<b>C</b>) SOD in the liver parenchyma. * Mean values were significantly different (<span class="html-italic">p</span>  &lt;  0.05). Details of measurement are described in the Materials and Method section.</p> Full article ">Figure 5
<p>Histological examination of liver. (<b>A</b>) Control group, dose of SeNPs: (<b>B</b>) 0.5, (<b>C</b>) 1.5, (<b>D</b>) 3.0 and (<b>E</b>) 5 mg/kg/diet.</p> Full article ">Figure 6
<p>Histological examination of intestine. (<b>A</b>) Control group, dose of SeNPs: (<b>B</b>) 0.5, (<b>C</b>) 1.5, (<b>D</b>) 3.0 and (<b>E</b>) 5 mg/kg/diet.</p> Full article ">
19 pages, 1167 KiB  
Article
Assessment of In Vitro Bioaccessibility and In Vivo Oral Bioavailability as Complementary Tools to Better Understand the Effect of Cooking on Methylmercury, Arsenic, and Selenium in Tuna
by Tania Charette, Danyel Bueno Dalto, Maikel Rosabal, J. Jacques Matte and Marc Amyot
Toxics 2021, 9(2), 27; https://doi.org/10.3390/toxics9020027 - 3 Feb 2021
Cited by 4 | Viewed by 3213
Abstract
Fish consumption is the main exposure pathway of the neurotoxicant methylmercury (MeHg) in humans. The risk associated with exposure to MeHg may be modified by its interactions with selenium (Se) and arsenic (As). In vitro bioaccessibility studies have demonstrated that cooking the fish [...] Read more.
Fish consumption is the main exposure pathway of the neurotoxicant methylmercury (MeHg) in humans. The risk associated with exposure to MeHg may be modified by its interactions with selenium (Se) and arsenic (As). In vitro bioaccessibility studies have demonstrated that cooking the fish muscle decreases MeHg solubility markedly and, as a consequence, its potential absorption by the consumer. However, this phenomenon has yet to be validated by in vivo models. Our study aimed to test whether MeHg bioaccessibility can be used as a surrogate to assess the effect of cooking on MeHg in vivo availability. We fed pigs raw and cooked tuna meals and collected blood samples from catheters in the portal vein and carotid artery at: 0, 30, 60, 90, 120, 180, 240, 300, 360, 420, 480 and 540 min post-meal. In contrast to in vitro models, pig oral bioavailability of MeHg was not affected by cooking, although the MeHg kinetics of absorption was faster for the cooked meal than for the raw meal. We conclude that bioaccessibility should not be readily used as a direct surrogate for in vivo studies and that, in contrast with the in vitro results, the cooking of fish muscle did not decrease the exposure of the consumer to MeHg. Full article
(This article belongs to the Section Exposome Analysis and Risk Assessment)
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<p>Methylmercury bioaccessibility (%) according to the digestive compartment assessed from raw and cooked tuna muscle (<span class="html-italic">n</span> = 5). GI: gastric plus intestinal bioaccessibility. Letters indicate a significant difference (Wilcoxon tests, <span class="html-italic">p</span> ≤ 0.05) between treatments. Error bars present the standard deviation of the quintuplicates.</p> Full article ">Figure 2
<p>Venous serum MeHg concentration (µg/L) of five individuals during the 540 min post-consumption of a single raw (1R, 2, 3) or cooked tuna meal (1C, 4, 5). Values differed from zero (time effect, <span class="html-italic">p</span> &lt; 0.05) and were influenced by treatments (time effect × treatment, <span class="html-italic">p</span> &lt; 0.05). Panel “All pigs” presents the average (± SEM) of venous serum MeHg concentration (µg/L) for raw (<span class="html-italic">n</span> = 3) and cooked (<span class="html-italic">n</span> = 3) tuna meals. Serum MeHg averages from raw and cooked treatments were similar (Wilcoxon test, <span class="html-italic">p</span> &gt; 0.05). Preconsumption concentration was subtracted from each value.</p> Full article ">Figure 3
<p>Relationship between the concentration of metal(loid)s in venous and arterial blood for all pigs and sampling times (<span class="html-italic">n</span> = 72). Blue points represent raw tuna meal, and red points represent cooked tuna meal. The dotted line shows the 1:1 slope, and the solid line signifies a significant regression slope with the gray area illustrating the confidence interval at 0.95.</p> Full article ">Figure 4
<p>Mean (± SD) proportion (%) of the total quantity of different elements distributed bebetween RBCs and the serum fraction over 540. min postprandial (<span class="html-italic">n</span> = 34 and 35 for the raw tuna meal, and <span class="html-italic">n</span> = 36 for the cooked tuna meal treatment). Total quantity of each blood compartment was adjusted to their respective volumes (RBC concentration was adjusted as a function of hematocrit (M<sub>RBC</sub> concentration × blood volume × hematocrit) and serum concentration as a function of serum volume (M<sub>serum</sub> concentration × blood volume × (1−hematocrit)). * indicates that mean proportion varies as a function of time (time effect, <span class="html-italic">p</span> &lt; 0.05). No difference was measured between the raw and cooked treatments (treatment effect, <span class="html-italic">p</span> &gt; 0.05).</p> Full article ">
13 pages, 503 KiB  
Review
A Review of Lysimeter Experiments Carried Out on Municipal Landfill Waste
by Dominika Dabrowska and Wojciech Rykala
Toxics 2021, 9(2), 26; https://doi.org/10.3390/toxics9020026 - 2 Feb 2021
Cited by 6 | Viewed by 2612
Abstract
The groundwater risk assessment in the vicinity of landfill sites requires, among others, representative monitoring and testing for pollutants leaching from the waste. Lysimeter studies can serve as an example of dynamic leaching tests. However, due to the bacteriological composition of the municipal [...] Read more.
The groundwater risk assessment in the vicinity of landfill sites requires, among others, representative monitoring and testing for pollutants leaching from the waste. Lysimeter studies can serve as an example of dynamic leaching tests. However, due to the bacteriological composition of the municipal waste, they are rarely carried out. These tests allow for the proper design of the landfill protection system against migration of pollutants into the ground, assessment of bacteriological, biochemical and chemical risk for the groundwater, determination of the water balance of leachate as well as examination of the course of processes taking place in the waste landfill with a diversified access to oxygen. This paper addresses the issue of performing lysimeter studies on a sample of municipal waste in various scientific centers. It analyzes the size of lysimeters, their construction, the method of water supply, the duration of the experiment, the scope of research, and the purpose of lysimeter studies. Full article
(This article belongs to the Special Issue Occurrence, Fate and Environmental Risk Assessment of the Organic Microcontaminants in Groundwater)
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<p>General sketch of the lysimeter.</p> Full article ">
18 pages, 1916 KiB  
Review
Benzodiazepines: Their Use either as Essential Medicines or as Toxics Substances
by Edilma Sanabria, Ronald Edgardo Cuenca, Miguel Ángel Esteso and Mauricio Maldonado
Toxics 2021, 9(2), 25; https://doi.org/10.3390/toxics9020025 - 1 Feb 2021
Cited by 25 | Viewed by 11966
Abstract
This review highlights the nature, characteristics, properties, pharmacological differences between different types of benzodiazepines, the mechanism of action in the central nervous system, and the degradation of benzodiazepines. In the end, the efforts to reduce the benzodiazepines’ adverse effects are shown and a [...] Read more.
This review highlights the nature, characteristics, properties, pharmacological differences between different types of benzodiazepines, the mechanism of action in the central nervous system, and the degradation of benzodiazepines. In the end, the efforts to reduce the benzodiazepines’ adverse effects are shown and a reflection is made on the responsible uses of these medications. Full article
(This article belongs to the Section Human Toxicology and Epidemiology)
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<p>Benzodiazepines basic structure.</p> Full article ">Figure 2
<p>Chemical structures of some benzodiazepines.</p> Full article ">Figure 3
<p>Some synthesis routes toward benzodiazepines.</p> Full article ">Figure 4
<p>Representation of the benzodiazepines (BDZ) action mechanism and their role in the nervous impulse inhibition.</p> Full article ">Figure 5
<p>Degradation of benzodiazepines into 2-aminobenzophenone and glycine.</p> Full article ">Figure 6
<p>Chlordiazepoxide structure; it was the first benzodiazepine introduced in the world.</p> Full article ">Figure 7
<p>Chemical structure of the benzodiazepine (Flunitrazepam) that, together with insulin, was administered into the victim’s mouthwash by the nurses Maria Gruber, Irene Leidolf, Stephanija Meyer, and Waltraud Wagner (the “<span class="html-italic">Lainz Angels of Death</span>”), murdering 43 persons in Vienna, Austria.</p> Full article ">Figure 8
<p>Chemical structure of Diazepam. It is believed that, under its effects, Stephen Paddock killed 58 persons during a concert in Las Vegas (USA), the first of October 2017.</p> Full article ">Figure 9
<p>Representation of the modification of basic benzodiazepines to obtain new types of benzodiazepines.</p> Full article ">Figure 10
<p>Structure of the benzodiazepines more linked to deaths.</p> Full article ">
32 pages, 5201 KiB  
Article
Cytotoxicity of Seaweed Compounds, Alone or Combined to Reference Drugs, against Breast Cell Lines Cultured in 2D and 3D
by Fernanda Malhão, Alice Abreu Ramos, Ana Catarina Macedo and Eduardo Rocha
Toxics 2021, 9(2), 24; https://doi.org/10.3390/toxics9020024 - 31 Jan 2021
Cited by 14 | Viewed by 3813
Abstract
Seaweed bioactive compounds have shown anticancer activities in in vitro and in vivo studies. However, tests remain limited, with conflicting results, and effects in combination with anticancer drugs are even scarcer. Here, the cytotoxic effects of five seaweed compounds (astaxanthin, fucoidan, fucosterol, laminarin, [...] Read more.
Seaweed bioactive compounds have shown anticancer activities in in vitro and in vivo studies. However, tests remain limited, with conflicting results, and effects in combination with anticancer drugs are even scarcer. Here, the cytotoxic effects of five seaweed compounds (astaxanthin, fucoidan, fucosterol, laminarin, and phloroglucinol) were tested alone and in combination with anticancer drugs (cisplatin—Cis; and doxorubicin—Dox), in breast cell lines (three breast cancer (BC) subtypes and one non-tumoral). The combinations revealed situations where seaweed compounds presented potentiation or inhibition of the drugs’ cytotoxicity, without a specific pattern, varying according to the cell line, concentration used for the combination, and drug. Fucosterol was the most promising compound, since: (i) it alone had the highest cytotoxicity at low concentrations against the BC lines without affecting the non-tumoral line; and (ii) in combination (at non-cytotoxic concentration), it potentiated Dox cytotoxicity in the triple-negative BC cell line. Using a comparative approach, monolayer versus 3D cultures, further investigation assessed effects on cell viability and proliferation, morphology, and immunocytochemistry targets. The cytotoxic and antiproliferative effects in monolayer were not observed in 3D, corroborating that cells in 3D culture are more resistant to treatments, and reinforcing the use of more complex models for drug screening and a multi-approach that should include histological and ICC analysis. Full article
(This article belongs to the Section Toxicology)
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Graphical abstract
Full article ">Figure 1
<p>Schematic representation of the study design.</p> Full article ">Figure 2
<p>Cytotoxic effect of (<b>a</b>) Astaxanthin (Asta), (<b>b</b>) Fucoidan (Fc), (<b>c</b>) Fucosterol (Fct), (<b>d</b>) Laminarin (Lm), and (<b>e</b>) Phloroglucinol (Phg) assessed by MTT assay after 72 h of exposure in the panel of breast cell lines cultured in monolayer. Control corresponds to cells with medium containing 0.1% DMSO. The percentages of cell viability are relative to the controls and presented as mean + standard deviation of six independent experiments (each in triplicate). (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001, **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 3
<p>Cytotoxic effect of (<b>a</b>) Cisplatin (Cis); (<b>b</b>) Doxorubicin (Dox) assessed by the MTT assay after 72 h of exposure in the panel of breast cell lines cultured in monolayer. Control corresponds to cells incubated with medium containing 0.1% DMSO. The percentages of cell viability are relative to the controls and presented as mean + standard deviation of six independent experiments (each in triplicate). (* <span class="html-italic">p</span> &lt; 0.05, *** <span class="html-italic">p</span> &lt; 0.001, **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 4
<p>Cytotoxic effects of the combination of (<b>a</b>) Astaxanthin (Asta); (<b>b</b>) Fucoidan (Fc); (<b>c</b>) Fucosterol (Fct); (<b>d</b>) Laminarin (Lm); (<b>e</b>) Phloroglucinol (Phg) with the reference drugs cisplatin (Cis) and doxorubicin (Dox) assessed by the MTT the assay after 72 h of exposure in MCF7 cell line cultured in monolayer. Control corresponds to cells incubated with medium containing 0.1% DMSO. The percentages of cell viability are relative to the control and presented as mean + standard deviation of six independent experiments (each in triplicate). Square brackets indicate <span class="html-italic">t</span> tests with Sequential Bonferroni corrections. (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01; *** <span class="html-italic">p</span> &lt; 0.001, **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 5
<p>Cytotoxic effects of the combination of (<b>a</b>) Astaxanthin (Asta); (<b>b</b>) Fucoidan (Fc); (<b>c</b>) Fucosterol (Fct); (<b>d</b>) Laminarin (Lm); (<b>e</b>) Phloroglucinol (Phg) with the reference drugs cisplatin (Cis) and doxorubicin (Dox) assessed by the MTT assay after 72 h of exposure in SKBR3 cell line cultured in monolayer. Control corresponds to cells incubated with medium containing 0.1% DMSO. The percentages of cell viability are relative to the control and presented as mean + standard deviation of six independent experiments (each in triplicate). Square brackets indicate <span class="html-italic">t</span> tests with Sequential Bonferroni corrections. (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01; *** <span class="html-italic">p</span> &lt; 0.001, **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 6
<p>Cytotoxic effects of the combination of (<b>a</b>) Astaxanthin (Asta); (<b>b</b>) Fucoidan (Fc); (<b>c</b>) Fucosterol (Fct); (<b>d</b>) Laminarin (Lm); (<b>e</b>) Phloroglucinol (Phg) with the reference drugs cisplatin (Cis) and doxorubicin (Dox) assessed by the MTT assay after 72 h of exposure in MDA-MB-231 cell line cultured in monolayer. Control corresponds to cells incubated with medium containing 0.1% DMSO. The percentages of cell viability are relative to the control and presented as mean + standard deviation of six independent experiments (each in triplicate). Square brackets indicate <span class="html-italic">t</span> tests with Sequential Bonferroni corrections. (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01; *** <span class="html-italic">p</span> &lt; 0.001, **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 7
<p>Cytotoxic effects of the combination of (<b>a</b>) Astaxanthin (Asta); (<b>b</b>) Fucoidan (Fc); (<b>c</b>) Fucosterol (Fct); (<b>d</b>) Laminarin (Lm); (<b>e</b>) Phloroglucinol (Phg) with the reference drugs cisplatin (Cis) and doxorubicin (Dox) assessed by the MTT assay after 72 h of exposure in MCF12A cell line cultured in monolayer. Control corresponds to cells incubated with medium containing 0.1% DMSO. The percentages of cell viability are relative to the control and presented as mean + standard deviation of six independent experiments (each in triplicate). (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01; *** <span class="html-italic">p</span> &lt; 0.001, **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 8
<p>Effect of fucosterol (Fct) at 5 µM alone and in combination with doxorubicin (Dox) at 0.1, 1, 2 and 5 µM, on the viability of MDA-MB-231 cells in monolayer–72 h (<b>a</b>) and 3D–96 h (<b>b</b>) assessed by the MTT assay. Cells treated with 0.1% DMSO and Dox 5 µM were included as negative and positive controls, respectively. The percentages of cell viability are relative to the control and presented as mean + standard deviation of five independent experiments (each in triplicate). (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01 and **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 9
<p>Effect of fucosterol (Fct) at 5 µM alone and in combination with doxorubicin (Dox) at 0.1, 1, 2, and 5 µM, on the viability of MDA-MB-231 cells in monolayer–72 h (<b>a</b>) and 3D–96 h (<b>b</b>) assessed by the resazurin assay. Cells treated with 0.1% DMSO and Dox 5 µM were included as negative and positive controls, respectively. The percentages of cell viability are relative to the control and presented as mean + standard deviation of five independent experiments (each in triplicate). Square brackets indicate <span class="html-italic">t</span> tests with Sequential Bonferroni corrections (** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001 and **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 10
<p>Effect of fucosterol (Fct) at 5 µM alone and in combination with doxorubicin (Dox) at 0.1, 1, 2, and 5 µM, on cell proliferation in monolayer–72 h (<b>a</b>) and 3D–96 h (<b>b</b>) assessed by BrdU assay. Cells treated with 0.1% DMSO and Dox 5 µM were included as negative and positive controls, respectively. The percentages of cell proliferation are relative to the control and presented as mean + standard deviation of five independent experiments (each in triplicate). (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01; *** <span class="html-italic">p</span> &lt; 0.001; **** <span class="html-italic">p</span> &lt; 0.0001).</p> Full article ">Figure 11
<p>Representative stereomicroscopic images of 3D cultures-MCAs in the tested conditions of fucosterol (Fct) at 5 µM alone, and in combination with doxorubicin (Dox) at 0.1, 1, 2, and 5 µM. Cells treated with 0.1% DMSO (C) and Dox (5 µM) were included as negative and positive controls, respectively (<b>a</b>). Two images of MCAs from C and Fct (5 µM) (red dashed circle) and Dox (5 µM) and Fct (5 µM) + Dox (5 µM) (white dashed circle) are overlapped to show the difference in cellular aggregation between the two tested conditions (<b>b</b>). Box and whisker graph of Areas of MCAs expressed as median, maximum, minimum, and interquartile range (Q3-Q1 of five independent experiments (16 MCAs/per tested condition/per experiment) (<b>c</b>). Significant differences: * <span class="html-italic">p</span> &lt; 0.05. Scale bar: 500 µm.</p> Full article ">Figure 12
<p>Representative histological images of MCAs exposed to the tested conditions: fucosterol (Fct) 5 µM alone and in combination with doxorubicin (Dox) 1, 2, and 5 µM. Cells treated with 0.1% DMSO correspond to the control (C). MCAs sections were stained with hematoxylin-eosin.</p> Full article ">Figure 13
<p>Representative histological images of MCAs immunostained against caspase-3 and ki67 after exposure to fucosterol (Fct) at 5 µM in combination with doxorubicin (Dox) at 1, 2 and 5 µM. Cells treated with 0.1% DMSO correspond to the control (C). Brown color-diaminobenzidine (DAB) indicates positive staining.</p> Full article ">
30 pages, 1367 KiB  
Review
Cognitive Impairment Induced by Lead Exposure during Lifespan: Mechanisms of Lead Neurotoxicity
by Daniela Ramírez Ortega, Dinora F. González Esquivel, Tonali Blanco Ayala, Benjamín Pineda, Saul Gómez Manzo, Jaime Marcial Quino, Paul Carrillo Mora and Verónica Pérez de la Cruz
Toxics 2021, 9(2), 23; https://doi.org/10.3390/toxics9020023 - 28 Jan 2021
Cited by 100 | Viewed by 10760
Abstract
Lead (Pb) is considered a strong environmental toxin with human health repercussions. Due to its widespread use and the number of people potentially exposed to different sources of this heavy metal, Pb intoxication is recognized as a public health problem in many countries. [...] Read more.
Lead (Pb) is considered a strong environmental toxin with human health repercussions. Due to its widespread use and the number of people potentially exposed to different sources of this heavy metal, Pb intoxication is recognized as a public health problem in many countries. Exposure to Pb can occur through ingestion, inhalation, dermal, and transplacental routes. The magnitude of its effects depends on several toxicity conditions: lead speciation, doses, time, and age of exposure, among others. It has been demonstrated that Pb exposure induces stronger effects during early life. The central nervous system is especially vulnerable to Pb toxicity; Pb exposure is linked to cognitive impairment, executive function alterations, abnormal social behavior, and fine motor control perturbations. This review aims to provide a general view of the cognitive consequences associated with Pb exposure during early life as well as during adulthood. Additionally, it describes the neurotoxic mechanisms associated with cognitive impairment induced by Pb, which include neurochemical, molecular, and morphological changes that jointly could have a synergic effect on the cognitive performance. Full article
(This article belongs to the Special Issue Toxicity, Mechanism, and Health Effect of Metals and Their Detoxification Strategies)
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<p>Cognitive and behavioral changes induced by Pb exposure in humans and associated morphologic, cellular, and molecular alterations of Pb toxicity.</p> Full article ">Figure 2
<p>Mechanisms involved in Pb toxicity in the CNS. Pb can enter the CNS through DMT1 and calcium transporters. In the presynaptic neuron, Pb binds with greater affinity to voltage-gated calcium channels and decreases transportation of calcium ions. Through these channels, Pb can cross inside the cell. Once inside, Pb interacts through Ca<sup>2+</sup> binding sites, with several neuronal components involved in vesicular mobilization and docking, affecting the vesicular mobilization and the neurotransmitter release, thus decreasing the activation of postsynaptic receptors. Pb can form Pb–NMDA complexes altering the intracellular levels of Ca<sup>2+</sup> in the postsynaptic neuron. The kynurenic acid produced in the astrocytes and rise by Pb contributes to LTP dysfunction. Finally, Pb alters the redox environment, promoting an oxidant environment and cell death.</p> Full article ">
13 pages, 1936 KiB  
Article
Impact of Acid-Base Status on Mortality in Patients with Acute Pesticide Poisoning
by Hyo-Wook Gil, Min Hong, HwaMin Lee, Nam-jun Cho, Eun-Young Lee and Samel Park
Toxics 2021, 9(2), 22; https://doi.org/10.3390/toxics9020022 - 23 Jan 2021
Cited by 6 | Viewed by 2417
Abstract
We investigated clinical impacts of various acid-base approaches (physiologic, base excess (BE)-based, and physicochemical) on mortality in patients with acute pesticide intoxication and mutual intercorrelated effects using principal component analysis (PCA). This retrospective study included patients admitted from January 2015 to December 2019 [...] Read more.
We investigated clinical impacts of various acid-base approaches (physiologic, base excess (BE)-based, and physicochemical) on mortality in patients with acute pesticide intoxication and mutual intercorrelated effects using principal component analysis (PCA). This retrospective study included patients admitted from January 2015 to December 2019 because of pesticide intoxication. We compared parameters assessing the acid-base status between two groups, survivors and non-survivors. Associations between parameters and 30-days mortality were investigated. A total of 797 patients were analyzed. In non-survivors, pH, bicarbonate concentration (HCO3−), total concentration of carbon dioxide (tCO2), BE, and effective strong ion difference (SIDe) were lower and apparent strong ion difference (SIDa), strong ion gap (SIG), total concentration of weak acids, and corrected anion gap (corAG) were higher than in survivors. In the multivariable logistic analysis, BE, corAG, SIDa, and SIDe were associated with mortality. PCA identified four principal components related to mortality. SIDe, HCO3−, tCO2, BE, SIG, and corAG were loaded to principal component 1 (PC1), referred as total buffer bases to receive and handle generated acids. PC1 was an important factor in predicting mortality irrespective of the pesticide category. PC3, loaded mainly with pCO2, suggested respiratory components of the acid-base system. PC3 was associated with 30-days mortality, especially in organophosphate or carbamate poisoning. Our study showed that acid-base abnormalities were associated with mortality in patients with acute pesticide poisoning. We reduced these variables into four PCs, resembling the physicochemical approach, revealed that PCs representing total buffer bases and respiratory components played an important role in acute pesticide poisoning. Full article
(This article belongs to the Section Human Toxicology and Epidemiology)
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<p>Flow chart showing the inclusion and exclusion of patients in the study.</p> Full article ">Figure 2
<p>Pearson’s correlation between each parameter assessing acid-base status.</p> Full article ">Figure 3
<p>Factor loadings after principal component analysis. The figures representing factor loading in Cartesian coordiates between PC1 and PC2 (<b>A</b>), PC1 and PC3 (<b>B</b>), PC1 and PC4 (<b>C</b>), PC2 and PC3 (<b>D</b>), PC2 and PC4 (<b>E</b>), and PC3 and PC4 (<b>F</b>).</p> Full article ">Figure 4
<p>Differences in principal components according to the pesticide category. (<b>A</b>) principal component 1, (<b>B</b>) principal component 2, (<b>C</b>) principal component 3, and (<b>D</b>) principal component 4. * <span class="html-italic">p</span> &lt; 0.05, *** <span class="html-italic">p</span> &lt; 0.001.</p> Full article ">
29 pages, 2264 KiB  
Review
Impacts of Neonicotinoids on Molluscs: What We Know and What We Need to Know
by Endurance E Ewere, Amanda Reichelt-Brushett and Kirsten Benkendorff
Toxics 2021, 9(2), 21; https://doi.org/10.3390/toxics9020021 - 22 Jan 2021
Cited by 21 | Viewed by 5215
Abstract
The broad utilisation of neonicotinoids in agriculture has led to the unplanned contamination of adjacent terrestrial and aquatic systems around the world. Environmental monitoring regularly detects neonicotinoids at concentrations that may cause negative impacts on molluscs. The toxicity of neonicotinoids to some non-target [...] Read more.
The broad utilisation of neonicotinoids in agriculture has led to the unplanned contamination of adjacent terrestrial and aquatic systems around the world. Environmental monitoring regularly detects neonicotinoids at concentrations that may cause negative impacts on molluscs. The toxicity of neonicotinoids to some non-target invertebrates has been established; however, information on mollusc species is limited. Molluscs are likely to be exposed to various concentrations of neonicotinoids in the soil, food and water, which could increase their vulnerability to other sources of mortality and cause accidental exposure of other organisms higher in the food chain. This review examines the impacts of various concentrations of neonicotinoids on molluscs, including behavioural, physiological and biochemical responses. The review also identifies knowledge gaps and provides recommendations for future studies, to ensure a more comprehensive understanding of impacts from neonicotinoid exposure to molluscs. Full article
(This article belongs to the Special Issue Impacts of Agrochemicals on Aquatic Ecosystems: Assessing Responses across Biological Scales)
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<p>Structure of commercially available nitro- and cyano-neonicotinoids showing the amine groups (blue).</p> Full article ">Figure 2
<p>The number of review and journal articles on the impacts of neonicotinoids on molluscs showing increasing trend from 1995 to 2020.</p> Full article ">Figure 3
<p>Summary of studies on the impacts of neonicotinoids on molluscs based on several factors: habitat type (<b>A</b>), study design (<b>B</b>), class of molluscs (<b>C</b>), and neonicotinoid type (<b>D</b>).</p> Full article ">Figure 4
<p>A conceptual network of the different parameters tested in a bivalve (oyster) after exposure to imidacloprid (IMI): Green = No effect; Red = Increase/elevation; Blue = Inhibition/Reduction; +, Absorbed; ++, Accumulated; -, Reduced concentration; --, Further reduction; d, Barely detected; nd, Not detected. SFA, Saturated fatty acid; PUFA, Polyunsaturated fatty acid; MUFA, Monounsaturated fatty acid; <span class="html-italic">n</span>-3, Omega 3 fatty acids; <span class="html-italic">n</span>-6, Omega 6 fatty acids; FR, Filtration rate; DG, Digestive gland; CI, Condition index; AChE, Acetylcholinesterase; CAT, Catalase; GST, Glutathione S-transferase; AM, Adductor muscle; HSPs, heat shock proteins; SOD, Extracellular superoxide dismutase. Source: Ewere [<a href="#B151-toxics-09-00021" class="html-bibr">151</a>].</p> Full article ">
9 pages, 2232 KiB  
Article
Sublethal Effects of Chlorantraniliprole on Spodoptera litura (Lepidoptera: Noctuidae) Moth: Implication for Attract-And-Kill Strategy
by Fanfang Kong, Yaqin Song, Qian Zhang, Zhongyue Wang and Yongqiang Liu
Toxics 2021, 9(2), 20; https://doi.org/10.3390/toxics9020020 - 22 Jan 2021
Cited by 12 | Viewed by 3021
Abstract
The integrated use of plant-derived volatile attractants and synthetic insecticides in attract-and-kill programs is a useful tool for integrated pest management programs reducing pesticide input. Efficient alternative insecticides are critically needed to replace methomyl, which has been banned on cruciferous vegetables in China [...] Read more.
The integrated use of plant-derived volatile attractants and synthetic insecticides in attract-and-kill programs is a useful tool for integrated pest management programs reducing pesticide input. Efficient alternative insecticides are critically needed to replace methomyl, which has been banned on cruciferous vegetables in China because it is also highly toxic to nontarget organisms. In the present study, among 15 commonly used insecticides were screened for toxicity against S. litura moths, where chlorantraniliprole, flubendiamide, and emamectin benzoate was found to have the highest levels of toxicity (LC50 of 0.56, 3.85, and 6.03 mg a.i. L−1 respectively). After exposure to the low lethal concentration LC50 of chlorantraniliprole, fecundity of the moths was substantially reduced. Egg-hatching was lower for LC20- and LC50-treated moth pairs than for untreated control pairs. Net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) were significantly reduced in LC50♀ × LC50♂ cohorts. Larval mortality was significantly higher in subsequent generations in pairs of LC50-treated moths. Chlorantraniliprole, which was most toxic and had significant sublethal effects on moths, can be used as an alternative insecticide to methomyl in the attracticide for controlling S. litura moths, and the LC50 indicated a high potential for efficacy in the control S. litura through attract-and-kill schemes. Full article
(This article belongs to the Special Issue Hazard Assessment of Endocrine Disrupting Chemicals in Invertebrates)
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<p>Linear regression of morality (probit unit) of <span class="html-italic">Spodoptera litura</span> and chlorantraniliprole concentration (logtransformed).</p> Full article ">Figure 2
<p>Effects of chlorantraniliprole at sublethal doses on the longevity and fecundity of <span class="html-italic">Spodoptera litura</span> after treatment in the adults. CK♀, LC<sub>20</sub>♀, and LC<sub>50</sub>♀ mean the surviving females from control, and LC<sub>20</sub> and LC<sub>50</sub> are the treated cohorts that were used to pair with males, respectively; CK♂, LC<sub>20</sub>♂, and LC<sub>50</sub>♂ mean the surviving males from control, and LC<sub>20</sub> and LC<sub>50</sub> are the treated cohorts that were used to pair with females, respectively. “Fecundity” is the number of eggs laid per female. Different letters above bars indicate a significant intermonth difference at the 5% level in Tukey’s HSD tests.</p> Full article ">
16 pages, 7223 KiB  
Article
Coordination Properties of the Fungal Metabolite Harzianic Acid Toward Toxic Heavy Metals
by Gaetano De Tommaso, Maria Michela Salvatore, Rosario Nicoletti, Marina DellaGreca, Francesco Vinale, Alessia Staropoli, Francesco Salvatore, Matteo Lorito, Mauro Iuliano and Anna Andolfi
Toxics 2021, 9(2), 19; https://doi.org/10.3390/toxics9020019 - 20 Jan 2021
Cited by 13 | Viewed by 2403
Abstract
Some Trichoderma strains are known for their capacity to produce harzianic acid, a metabolite belonging to the tetramic acid derivatives. Harzianic acid has interesting biological properties, such as antimicrobial activities against phytopathogenic fungi and promotion of plant growth. It also possesses remarkable chemical [...] Read more.
Some Trichoderma strains are known for their capacity to produce harzianic acid, a metabolite belonging to the tetramic acid derivatives. Harzianic acid has interesting biological properties, such as antimicrobial activities against phytopathogenic fungi and promotion of plant growth. It also possesses remarkable chemical properties, including the chelating properties toward essential transition metals, which might be related to the biological activities. Increasing knowledge on chelating properties might be relevant for understanding the various beneficial effects of harzianic acid in the interaction between the producer fungi and plants. In this work, the coordination capacity of harzianic acid was studied to evaluate the formation and stability of complexes formed with toxic heavy metals (i.e., Cd2+, Co2+, Ni2+, and Pb2+), which might have a crucial role in the tolerance of plants growing in metal-contaminated soils and in abiotic stress. Full article
(This article belongs to the Special Issue Toxicity, Mechanism, and Health Effect of Metals and Their Detoxification Strategies)
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Figure 1

Figure 1
<p>Structures of harzianic acid (H<sub>2</sub>L) and its acid dissociation products (HL<sup>−</sup> and L<sup>2−</sup>). Reported dissociation constants of harzianic acid have been separately determined at 25 °C in the mixed solvent CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>), which is the solvent employed in this study.</p> Full article ">Figure 2
<p>Far–UV circular dichroism (CD) spectra (optical path 0.2 cm) in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) at different pH values: (<b>A</b>)<math display="inline"><semantics> <mrow> <mo> </mo> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Pb</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 5.4 × 10<sup>−5</sup> M Pb(ClO<sub>4</sub>)<sub>2</sub> and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 1.1 × 10<sup>−4</sup> M; (<b>B</b>)<math display="inline"><semantics> <mrow> <msubsup> <mrow> <mrow> <mo> </mo> <mi mathvariant="normal">C</mi> </mrow> </mrow> <mrow> <mi>Cd</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 1.4 × 10<sup>−4</sup> M Cd(ClO<sub>4</sub>)<sub>2</sub> and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.6 × 10<sup>−4</sup> M; (<b>C</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Co</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 6.9 × 10<sup>−5</sup> M CoCl<sub>2</sub> and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math>= 1.4 × 10<sup>−4</sup> M; (<b>D</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Ni</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 1.1·10<sup>−4</sup> M NiCl<sub>2</sub> and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.1 × 10<sup>−4</sup> M. H<sub>2</sub>L = harzianic acid.</p> Full article ">Figure 3
<p>UV-VIS spectra in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) at different pH of: (<b>A</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Cd</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> Cd(ClO<sub>4</sub>)<sub>2</sub> (ligand to metal ratio 1:1); (<b>B</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Cd</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 4.0 × 10<sup>−4</sup> Cd(ClO<sub>4</sub>)<sub>2</sub> (ligand to metal ratio 1:2).</p> Full article ">Figure 4
<p>UV-VIS spectra in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) at different pH of: (<b>A</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Co</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> CoCl<sub>2</sub> (ligand to metal ratio 1:1); (<b>B</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Co</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 4.0 × 10<sup>−4</sup> CoCl<sub>2</sub> (ligand to metal ratio 1:2).</p> Full article ">Figure 5
<p>UV-VIS spectra in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) at different pH of: (<b>A</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Ni</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> NiCl<sub>2</sub> (ligand to metal ratio 1:1); (<b>B</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Ni</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 4.0 × 10<sup>−4</sup> NiCl<sub>2</sub> (ligand to metal ratio 1:2).</p> Full article ">Figure 6
<p>UV-VIS spectra in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) at different pH of: (<b>A</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Pb</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> Pb(ClO<sub>4</sub>)<sub>2</sub> (ligand to metal ratio 1:1); (<b>B</b>) <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 2.0 × 10<sup>−4</sup> M and <math display="inline"><semantics> <mrow> <msubsup> <mi mathvariant="normal">C</mi> <mrow> <mi>Pb</mi> </mrow> <mn>0</mn> </msubsup> </mrow> </semantics></math> = 4.0 × 10<sup>−4</sup>Pb(ClO<sub>4</sub>)<sub>2</sub> (ligand to metal ratio 1:2).</p> Full article ">Figure 7
<p>pH scan of a 10<sup>−4</sup> M aqueous solution of Pb<sup>2+</sup> based on stoichiometry and formation constants of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>Pb</mi> </mrow> <mi mathvariant="normal">m</mi> </msub> <msubsup> <mrow> <mo stretchy="false">(</mo> <mi>OH</mi> <mo stretchy="false">)</mo> </mrow> <mi mathvariant="normal">n</mi> <mrow> <mn>2</mn> <mi mathvariant="normal">m</mi> <mo>−</mo> <mi mathvariant="normal">n</mi> </mrow> </msubsup> </mrow> </semantics></math> hydroxo complexes gathered from literature [<a href="#B45-toxics-09-00019" class="html-bibr">45</a>,<a href="#B46-toxics-09-00019" class="html-bibr">46</a>].</p> Full article ">Figure 8
<p>Molar extinction coefficients, <math display="inline"><semantics> <mrow> <msub> <mi mathvariant="sans-serif">ε</mi> <mi mathvariant="sans-serif">λ</mi> </msub> </mrow> </semantics></math> (M<sup>−1</sup> cm<sup>−1</sup>), of the absorbing species calculated by Hyperquad for the systems: (<b>A</b>) Co<sup>2+</sup>-harzianic acid; (<b>B</b>) Ni<sup>2+</sup>-harzianic acid.</p> Full article ">Figure 9
<p>Distribution diagram of species in Cd<sup>2+</sup>-harzianic acid system in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) calculated from formation constants in <a href="#toxics-09-00019-t002" class="html-table">Table 2</a> assuming a <math display="inline"><semantics> <mrow> <msub> <mi mathvariant="normal">C</mi> <mrow> <mi>Cd</mi> </mrow> </msub> </mrow> </semantics></math> = 1.0 × 10<sup>−3</sup> M and <math display="inline"><semantics> <mrow> <msub> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> </msub> </mrow> </semantics></math> = 2.0 × 10<sup>−3</sup> M (H<sub>2</sub>L = harzianic acid). The symbol Cd* is used to represent all species in the solution that contain the metal cation, but do not contain harzianic acid.</p> Full article ">Figure 10
<p>Distribution diagram of species in Co<sup>2+</sup>-harzianic acid system in CH<sub>3</sub>OH/0.1 M NaClO<sub>4</sub> (50:50 <span class="html-italic">w/w</span>) calculated from formation constants in <a href="#toxics-09-00019-t002" class="html-table">Table 2</a> assuming <math display="inline"><semantics> <mrow> <msub> <mi mathvariant="normal">C</mi> <mrow> <mi>Co</mi> </mrow> </msub> </mrow> </semantics></math> = 1.0 × 10<sup>−3</sup> M and <math display="inline"><semantics> <mrow> <msub> <mi mathvariant="normal">C</mi> <mrow> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> <mi mathvariant="normal">L</mi> </mrow> </msub> </mrow> </semantics></math> = 2.0 × 10<sup>−3</sup> M (H<sub>2</sub>L = harzianic acid). The symbol Co* is used to represent all species in the solution that contain the metal cation, but do not contain harzianic acid.</p> Full article ">Scheme 1
<p>Sketch of the potentiometric apparatus employed to prepare test solutions, TS, of accurately known pH and analytical composition. RE represents the double junction Ag/AgCl(s)/0.1 M NaCl/(0.1 M NaClO<sub>4</sub>-CH<sub>3</sub>OH, 50/50 <span class="html-italic">w/w</span>) reference electrode and GE a pH indicator glass electrode.</p> Full article ">Scheme 2
<p>Chelation of metal cations, M<sup>2+</sup>, by harzianic acid.</p> Full article ">
22 pages, 1650 KiB  
Review
Mechanistic Implications of Biomass-Derived Particulate Matter for Immunity and Immune Disorders
by Arulkumar Nagappan, Su Bum Park, Su-Jun Lee and Yuseok Moon
Toxics 2021, 9(2), 18; https://doi.org/10.3390/toxics9020018 - 20 Jan 2021
Cited by 18 | Viewed by 4420
Abstract
Particulate matter (PM) is a major and the most harmful component of urban air pollution, which may adversely affect human health. PM exposure has been associated with several human diseases, notably respiratory and cardiovascular diseases. In particular, recent evidence suggests that exposure to [...] Read more.
Particulate matter (PM) is a major and the most harmful component of urban air pollution, which may adversely affect human health. PM exposure has been associated with several human diseases, notably respiratory and cardiovascular diseases. In particular, recent evidence suggests that exposure to biomass-derived PM associates with airway inflammation and can aggravate asthma and other allergic diseases. Defective or excess responsiveness in the immune system regulates distinct pathologies, such as infections, hypersensitivity, and malignancies. Therefore, PM-induced modulation of the immune system is crucial for understanding how it causes these diseases and highlighting key molecular mechanisms that can mitigate the underlying pathologies. Emerging evidence has revealed that immune responses to biomass-derived PM exposure are closely associated with the risk of diverse hypersensitivity disorders, including asthma, allergic rhinitis, atopic dermatitis, and allergen sensitization. Moreover, immunological alteration by PM accounts for increased susceptibility to infectious diseases, such as tuberculosis and coronavirus disease-2019 (COVID-19). Evidence-based understanding of the immunological effects of PM and the molecular machinery would provide novel insights into clinical interventions or prevention against acute and chronic environmental disorders induced by biomass-derived PM. Full article
(This article belongs to the Special Issue Molecular Basis of Air-Pollution-Induced Disease Risk)
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Figure 1
<p>A schematic diagram of PM exposure-induced innate immune responses. Lung mucosal exposure to PM can affect the innate immunity-associated human disease outcomes. PM exposure alters pattern recognition receptor (PRR)-linked innate immunity and subsequent adaptive immunity to infectious agents or allergens. During the pathologic process, various types of endogenous molecules, including reactive oxygen species (ROS) and cytokines, are involved in pulmonary tissue injuries or systemic immune dysfunctions via circulation. In particular, PM-insulted disruption of immunity may lead to infection, hypersensitivity, and chronic disorders. Excess oxidative stress can change the profile of Th cell-polarizing cytokines. Moreover, PM exposure can alter the expression of key transcription factors (GATA3 and T-bet) and disrupt the balance between Th1 and Th2 cells, influencing the disease severity.</p> Full article ">Figure 2
<p>Impacts of PM on macrophage polarization and disease outcomes. (<b>A</b>) There are two kinds of macrophages. Classically activated macrophages (M1) and alternatively activated macrophages (M2) are functionality corresponding to the Th1/Th2 paradigm. Macrophages differentiate into M1 type in response to INF-γ from Th1 cells and LPS, and M2 type in response to IL-4 and IL-13 from Th2 cells. Both M1 and M2 macrophages have a distinct phenotype, and they release pro-and anti-inflammatory cytokines, respectively. (<b>B</b>) Exposure to PM induced polarization towards M1 (exposure regime 1) or M2 (exposure regime 2) is associated with various respiratory and systemic immune disorders.</p> Full article ">Figure 3
<p>Schematic diagram of mechanisms of PM-induced oxidative stress and inflammation in the lung. When PM is inhaled, oxidative stress is initially triggered in the airways. Redox-active chemicals are transition metals, quinones, and organic components like PAH, which are responsible for the generation of ROS and stimulate the production of endogenous through AhR-induced CYP and NADPH oxidase. Moreover, the AhR-XRE system can enhance the production of proinflammatory cytokines. In spite of the Nrf2-ARE-associated antioxidant system for antioxidant enzymes and phase II enzymes, it fails to activate protection against the oxidative and proinflammatory burst, leading to lung and extrapulmonary tissue damages during PM-induced hypersensitivity.</p> Full article ">
5 pages, 209 KiB  
Editorial
Acknowledgment to Reviewers of Toxics in 2020
by Toxics Editorial Office
Toxics 2021, 9(2), 17; https://doi.org/10.3390/toxics9020017 - 20 Jan 2021
Viewed by 1346
Abstract
Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that Toxics maintains its standards for the high quality of its published papers [...] Full article
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