Toxics

16 pages, 337 KiB

Open AccessArticle

Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers

by Pornpimol Kongtip, Noppanun Nankongnab, Ritthirong Pundee, Nichcha Kallayanatham, Sumate Pengpumkiat, Jutamanee Chungcharoen, Chavisa Phommalachai, Pajaree Konthonbut, Nattagorn Choochouy, Preecha Sowanthip, Phanthawee Khangkhun, Jutharak Yimsabai and Susan Woskie

Toxics 2021, 9(1), 16; https://doi.org/10.3390/toxics9010016 - 19 Jan 2021

Cited by 20 | Viewed by 4151

Abstract

The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the [...] Read more.

The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the day before spraying, farmers collected their first morning void urine and went for blood collection. On the spray day, urine samples were collected at end of the spraying event and they were interviewed with questionnaires. The next morning, the first morning void urine and blood samples were collected. Blood samples were analyzed for thyroid hormones. Urine samples were analyzed for the metabolites of the pesticide sprayed. The results showed that the thyroid hormones, free triiodothyronine (FT3) and total triiodothyronine (T3) were significantly reduced as urinary chlorpyrifos metabolite increased the day after spraying. Total thyroxine (T4) significantly increased as cypermethrin metabolites increased the day after spraying. T4 significantly increased as urinary glyphosate levels increased; however, FT3 and T3 decreased significantly as urinary paraquat levels increased the day after spraying. These findings suggest that acute exposures to the pesticides chlorpyrifos, cypermethrin, paraquat and glyphosate can produce acute effects on the hypothalamic–pituitary–thyroid (HPT) axis, acutely altering thyroid hormone levels. Full article

(This article belongs to the Special Issue Environmental Exposures Contributing to Thyroid Cancer Risk)

10 pages, 2321 KiB

Open AccessArticle

The Presence of Selected Elements in the Microscopic Image of Pine Needles as an Effect of Cement and Lime Pressure within the Region of Białe Zagłębie (Central Europe)

by Mirosław Szwed, Witold Żukowski and Rafał Kozłowski

Toxics 2021, 9(1), 15; https://doi.org/10.3390/toxics9010015 - 19 Jan 2021

Cited by 10 | Viewed by 2531

Abstract

In this study, we present the results of microscopic observations of pine needles Pinus sylvestris L. collected in the area of cement-lime pressure in the south-western part of the Świętokrzyskie Mountains in the region of Białe Zagłębie. Images of scanning electron microscopy (SEM) [...] Read more.

In this study, we present the results of microscopic observations of pine needles Pinus sylvestris L. collected in the area of cement-lime pressure in the south-western part of the Świętokrzyskie Mountains in the region of Białe Zagłębie. Images of scanning electron microscopy (SEM) confirm the presence of particles with a size of about 2 to 20 µm on the surface of the needles. Analysis using X-ray energy dispersion spectroscopy (EDS) allowed, in turn, to identify lead, iron, aluminium, calcium, and silicon in particles deposited in the surface layer of assimilation organs and dispersed in the surface layer of vegetation tissue within cell structures. Chemical composition, size and shape of particles of foreign bodies on the needles’ surface allow them to be identified as cement-lime dust coming from production plants located in the Białe Zagłębie. Negative influence on the condition and liveliness of Scots pine in the study area is manifested by images on which stomata is sealed, which limits the possibility of gas exchange. Full article

(This article belongs to the Special Issue Analytical Chemistry of Air Pollution)

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26 pages, 400 KiB

Open AccessFeature PaperReview

Endocrine Disrupting Chemicals and Thyroid Cancer: An Overview

by Mathilda Alsen, Catherine Sinclair, Peter Cooke, Kimia Ziadkhanpour, Eric Genden and Maaike van Gerwen

Toxics 2021, 9(1), 14; https://doi.org/10.3390/toxics9010014 - 19 Jan 2021

Cited by 69 | Viewed by 8664

Abstract

Endocrine disruptive chemicals (EDC) are known to alter thyroid function and have been associated with increased risk of certain cancers. The present study aims to provide a comprehensive overview of available studies on the association between EDC exposure and thyroid cancer. Relevant studies [...] Read more.

Endocrine disruptive chemicals (EDC) are known to alter thyroid function and have been associated with increased risk of certain cancers. The present study aims to provide a comprehensive overview of available studies on the association between EDC exposure and thyroid cancer. Relevant studies were identified via a literature search in the National Library of Medicine and National Institutes of Health PubMed as well as a review of reference lists of all retrieved articles and of previously published relevant reviews. Overall, the current literature suggests that exposure to certain congeners of flame retardants, polychlorinated biphenyls (PCBs), and phthalates as well as certain pesticides may potentially be associated with an increased risk of thyroid cancer. However, future research is urgently needed to evaluate the different EDCs and their potential carcinogenic effect on the thyroid gland in humans as most EDCs have been studied sporadically and results are not consistent. Full article

(This article belongs to the Special Issue Environmental Exposures Contributing to Thyroid Cancer Risk)

20 pages, 1750 KiB

Open AccessReview

Multi-Criteria Decision Making Approaches Applied to Waste Electrical and Electronic Equipment (WEEE): A Comprehensive Literature Review

by Samuele Marinello and Rita Gamberini

Toxics 2021, 9(1), 13; https://doi.org/10.3390/toxics9010013 - 18 Jan 2021

Cited by 30 | Viewed by 4595

Abstract

The global demand for electrical and electronic equipment has undergone continuous growth in recent years due to the effect of industrialization and technological development. This indicates substantial quantities of e-waste that need to be managed properly to reduce their environmental impact and to [...] Read more.

The global demand for electrical and electronic equipment has undergone continuous growth in recent years due to the effect of industrialization and technological development. This indicates substantial quantities of e-waste that need to be managed properly to reduce their environmental impact and to avoid inappropriate forms of disposal. The purpose of this paper is to review the most popular multi-criteria decision-making approaches applied to the management of waste electrical and electronic equipment, analyzing how they are used to contribute to the improvement of management strategies along the entire supply chain. For this purpose, a methodological protocol for the collection, selection, and analysis of the scientific literature was applied, identifying 44 papers on which to conduct this study. The results showed that numerous authors have developed multi-criteria approaches, with particular attention to recycling phase. The analytic hierarchy process is the most widespread multi-criteria approach, often coupled with VIKOR, DELPHI, and TOPSIS methods. The numerous decision making criteria adopted cover different reference dimensions: environmental, economic, social, technical, and legal. Considering environmental aspects also in decision making processes means enhancing the relevance of this dimension, as well as encouraging practices that reduce the impact of toxic substances on the environment and living organisms. Full article

(This article belongs to the Special Issue Electronic-Waste: Management and Challenges)

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11 pages, 2120 KiB

Open AccessFeature PaperArticle

Developmental Hazard of Environmentally Persistent Free Radicals and Protective Effect of TEMPOL in Zebrafish Model

by Xia Guan, Lisa Truong, Slawomir M. Lomnicki, Robyn L. Tanguay and Stephania A. Cormier

Toxics 2021, 9(1), 12; https://doi.org/10.3390/toxics9010012 - 16 Jan 2021

Cited by 6 | Viewed by 2914

Abstract

Environmentally persistent free radicals (EPFRs) can be detected in ambient PM_2.5, cigarette smoke, and soils and are formed through combustion and thermal processing of organic materials. The hazards of EPFRs are largely unknown. In this study, we assess the developmental toxicity [...] Read more.

Environmentally persistent free radicals (EPFRs) can be detected in ambient PM_2.5, cigarette smoke, and soils and are formed through combustion and thermal processing of organic materials. The hazards of EPFRs are largely unknown. In this study, we assess the developmental toxicity of EPFRs and the ability of TEMPOL (4-Hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl) to protect against such hazards using zebrafish embryos. Particles containing EPFRs were acquired by dosing dichlorobenzene (DCB) vapor on the Cab-o-sil/5% CuO particles at 230 °C in vacuo (referred to as DCB-230). The particles were suspended in ultrapure water to make 1 mg/mL of stock solution from which series dilution was undertaken to obtain 10, 20, 30, 40, 50, 60, 80, and 100 µg/mL final test solutions, which were then placed in individual wells with a 4 h postfertilization (hpf) zebrafish embryo. Plates were run in duplicate to obtain a sample size of 24 animals per concentration; 12 embryos were exposed per concentration per plate. Statistical analysis of the morphology endpoints was performed. We investigated overt toxicity responses to DCB-230 in a 22-endpoint battery that included developing zebrafish from 24–120 hpf. Exposure to concentrations greater than 60 µg/mL of DCB-230 induced high mortality in the developmental zebrafish model. Exposure to EPFRs induced developmental hazards that were closely related to the concentrations of free radicals and EPFRs. The potential protective effects of TEMPOL against EPFRs’ toxicity in zebrafish were investigated. Exposure to EPFRs plus TEMPOL shifted the concentration to an induced 50% adverse effect (EC50), from 23.6 to 30.8 µg/mL, which verifies TEMPOL’s protective effect against EPFRs in the early phase of zebrafish development. Full article

(This article belongs to the Special Issue Advanced Zebrafish Model for Environmental Health Sciences Research)

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Incidence of overt toxicity responses to DCB-230 at 24 and 120 hpf. The top left inset is a depiction of 5 endpoints—two at 24 h (MO24 = mortality, DP24 = delayed development progression), and total mortality at five days (MORT). Two summary endpoints indicate individuals with any morbidity (any.except.MO), and any morbidity + mortality exhibited (any.effect). Each affected individual is illustrated as a circle and once a statistical threshold is passed, the individual is depicted as red. The logistic regression is shown over seven concentrations, with an EC50 of 54.8 µg/mL (red dotted line). The gray hash represents the two means’ standard deviations around the control. Statistical significance was determined using a Fishers Exact Test, p < 0.01. Full article ">Figure 2
Embryonic photomotor response in embryos. Embryos were developmentally exposed and kept in the dark until 24 hpf. At 24 hpf, a typical photomotor response was exhibited (black line) with occasional movement in the dark and increases in excited movement after the pulse of light (red vertical line); there was little to no activity after the second pulse of light. Full article ">Figure 3
Larval photomotor response to alternating light and dark cycles after static exposure of DCB-230. Data are reported as mean ± standard deviation at each second time bin. Only concentrations that comprised 70% phenotypically normal animals are displayed. Full article ">Figure 4
Incidence of overt toxicity responses to control DCB (at the concentrations of 0, 0.1, 0.5, 1, 2, 3, 4, and 5 µg/mL in ultrapure water) at 24 and 120 hpf. of the figure depicts five endpoints—two at 24 h (MO24 = Mortality, DP24 = delayed development progression), and total mortality at five days (MORT). Two summary endpoints indicate individuals with any morbidity (any.except.MO), and any morbidity + mortality exhibited (any.effect). Each affected individual is illustrated as a circle. Full article ">Figure 5
Incidence of overt toxicity responses to (A) static exposures and (B) daily renewal of PBN and TEMPOL at 24 and 120 hpf. MO24 = Mortality, DP24 = delayed development progression at 24 hpf, MORT = total mortality at five days. Two summary endpoints indicate individuals with any morbidity (any.except.MO), and any morbidity + mortality exhibited (any.effect). The other panels represent the morphological endpoints assessed. Each affected individual is illustrated as a circle and, once a statistical threshold is passed, the individual is depicted as red. YSE: yolk sac edema; AXIS: bent axis; EYE: abnormal eyes; SNOUT: abnormal snout; JAW: jaw; PE: pericardial edema and PFIN: pectoral fins. Full article ">Figure 6
Incidence of overt toxicity responses to DCB-230 and antioxidants at 120 hpf. The modeling of the data illustrates that DCB-230 alone (black) and DCB-230 + PBN (red) had similar EC50s while DCB-230 + TEMPOL (green) was distinctly different. Full article ">

13 pages, 1113 KiB

Open AccessArticle

Residential Green and Blue Spaces and Type 2 Diabetes Mellitus: A Population-Based Health Study in China

by Ruijia Li, Gongbo Chen, Anqi Jiao, Yuanan Lu, Yuming Guo, Shanshan Li, Chongjian Wang and Hao Xiang

Toxics 2021, 9(1), 11; https://doi.org/10.3390/toxics9010011 - 16 Jan 2021

Cited by 21 | Viewed by 4112

Abstract

Evidence on the health benefits of green space in residential environments is still limited, and few studies have investigated the potential association between blue space and type 2 diabetes mellitus (T2DM) prevalence. This study included 39,019 participants who had completed the baseline survey [...] Read more.

Evidence on the health benefits of green space in residential environments is still limited, and few studies have investigated the potential association between blue space and type 2 diabetes mellitus (T2DM) prevalence. This study included 39,019 participants who had completed the baseline survey from the Henan Rural Cohort Study, 2015–2017. The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) were employed to characterize the residential green space, and the distance from the participant’s residential address to the nearest water body was considered to represent the residential blue space. Mixed effect models were applied to evaluate the associations of the residential environment with T2DM and fasting blood glucose (FBG) levels. An interquartile range (IQR) increase in NDVI and EVI was significantly associated with a 13.4% (odds ratio (OR): 0.866, 95% Confidence interval (CI): 0.830,0.903) and 14.2% (OR: 0.858, 95% CI: 0.817,0.901) decreased risk of T2DM, respectively. The residential green space was associated with lower fasting blood glucose levels in men (%change, −2.060 in men vs. −0.972 in women) and the elderly (%change, −1.696 in elderly vs. −1.268 in young people). Additionally, people who lived more than 5 km from the water body had a 15.7% lower risk of T2DM (OR: 0.843, 95% CI: 0.770,0.923) and 1.829% lower fasting blood glucose levels (95% CI: −2.335%,−1.320%) than those who lived closer to the blue space. Our findings suggest that residential green space was beneficially associated with T2DM and fasting blood glucose levels. However, further research is needed to explore more comprehensively the relationship between residential blue space and public health. Full article

(This article belongs to the Special Issue Interactions across Different Exposures and Life-Stages in Exposome Research)

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15 pages, 1291 KiB

Open AccessArticle

Phylogenetic Integration Reveals the Zebrafish Core Microbiome and Its Sensitivity to Environmental Exposures

by Thomas J. Sharpton, Keaton Stagaman, Michael J. Sieler, Jr., Holly K. Arnold and Edward W. Davis II

Toxics 2021, 9(1), 10; https://doi.org/10.3390/toxics9010010 - 15 Jan 2021

Cited by 23 | Viewed by 4811

Abstract

Zebrafish are increasingly used to study how environmental exposures impact vertebrate gut microbes. However, we understand little about which microbial taxa are common to the zebrafish gut across studies and facilities. Here, we define the zebrafish core gut microbiome to resolve microbiota that [...] Read more.

Zebrafish are increasingly used to study how environmental exposures impact vertebrate gut microbes. However, we understand little about which microbial taxa are common to the zebrafish gut across studies and facilities. Here, we define the zebrafish core gut microbiome to resolve microbiota that are both relatively robust to study or facility effects and likely to drive proper microbiome assembly and functioning due to their conservation. To do so, we integrated publicly available gut microbiome 16S gene sequence data from eight studies into a phylogeny and identified monophyletic clades of gut bacteria that are unexpectedly prevalent across individuals. Doing so revealed 585 core clades of bacteria in the zebrafish gut, including clades within Aeromonas, Pseudomonas, Cetobacterium, Shewanella, Chitinibacter, Fluviicola, Flectobacillus, and Paucibacter. We then applied linear regression to discern which of these core clades are sensitive to an array of different environmental exposures. We found that 200 core clades were insensitive to any exposure we assessed, while 134 core clades were sensitive to more than two exposures. Overall, our analysis defines the zebrafish core gut microbiome and its sensitivity to exposure, which helps future studies to assess the robustness of their results and prioritize taxa for empirical assessments of how gut microbiota mediate the effects of exposure on the zebrafish host. Full article

(This article belongs to the Special Issue Advanced Zebrafish Model for Environmental Health Sciences Research)

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The phylogenetic composition of the zebrafish gut microbiome varies by study. These principle coordinate plots (PCoAs) illustrate the (A) weighted and (B) unweighted unifrac distance between all samples based on their amplicon sequence variant (ASV) profiles. Full article ">Figure 2
A small number of ASVs occur across multiple studies after merging ASVs that are identical or perfect substrings of other ASVs across studies. Both panels illustrate heatmaps that represent specific ASVs as rows and studies as columns. Panel (A) shows the prevalence of all ASVs detected in our analysis, ordered by their overall prevalence. Row bar plots illustrate the median prevalence per study (MSP), the overall prevalence, and whether the ASV occurs at least one time in at least one individual within a study (study occurrence). Panel (B) illustrates the same data but zooms in on the ASVs that are present in at least 5 studies. Row names correspond to the genus-level annotation of the ASV (or family in the case of an ambiguous genus-level annotation). Full article ">Figure 3
Core clade prevalence across all samples. In this heatmap, columns correspond to the specific samples evaluated in our analysis, grouped by study, and the rows correspond to each of the core clades detected in our investigation, grouped by their overall prevalence across samples. Full article ">Figure 4
The study-wide prevalence of the top 25% most prevalent clades. In this heatmap, columns correspond to the top 25% most prevalent core clades. Rows correspond to a particular study, and the cells illustrate the prevalence of the clade across the samples evaluated within each study. Hierarchical clustering and kmeans clustering support the existence of three groups of highly prevalent clades that are generally life stage-specific or robust to life stage. Full article ">Figure 5
The zebrafish core gut microbiome is phylogenetically diverse. The above cladograms illustrate the phylogenetic relationship of the ASVs detected across all samples subject to our analysis. All cladograms are identical in topology and represent the same set of ASVs, but differ in the information that associates with cladogram decoration. The lower left cladogram illustrates the phylogenetic location of each of the core clades detected in our analysis, where node color corresponds to the overall prevalence of each core clade. The ring of colors encircling the cladogram illustrates each ASV’s phylum level taxonomy. The clade to the immediate right illustrates the number of exposures to which each of these core clades is sensitive, as measured by negative binomial regression models. The smaller cladograms near the top illustrate which clades are sensitive to specific exposures (fdr < 0.1). Full article ">Figure 6
Core clades differentially respond to environmental exposures. In this heatmap, zebrafish gut microbiome core clades are represented as columns and exposure states included in different studies are represented as rows. Heatmap colors represent negative binomial model regression coefficients of the clade’s count within a rarefied sample as a function of the exposure. Both columns and rows were subject to hierarchical clustering and organized accordingly in the heatmap, as illustrated by the dendrograms decorating the top and left side of the heatmap. The bar plot to the right of the heatmap illustrates the number of core clades that were sensitive to the exposure in question (fdr < 0.1). Full article ">

10 pages, 1152 KiB

Open AccessFeature PaperArticle

Morphological and Behavioral Effects in Zebrafish Embryos after Exposure to Smoke Dyes

by Kimberly T. To, Lindsey St. Mary, Allyson H. Wooley, Mitchell S. Wilbanks, Anthony J. Bednar, Edward J. Perkins, Lisa Truong, Robyn L. Tanguay and Natàlia Garcia-Reyero

Toxics 2021, 9(1), 9; https://doi.org/10.3390/toxics9010009 - 10 Jan 2021

Cited by 10 | Viewed by 3242

Abstract

Solvent Violet 47 (SV47) and Disperse Blue 14 (DB14) are two anthraquinone dyes that were previously used in different formulations for the production of violet-colored smoke. Both dyes have shown potential for toxicity; however, there is no comprehensive understanding of their effects. Zebrafish [...] Read more.

Solvent Violet 47 (SV47) and Disperse Blue 14 (DB14) are two anthraquinone dyes that were previously used in different formulations for the production of violet-colored smoke. Both dyes have shown potential for toxicity; however, there is no comprehensive understanding of their effects. Zebrafish embryos were exposed to SV47 or DB14 from 6 to 120 h post fertilization (hpf) to assess the dyes’ potential adverse effects on developing embryos. The potential ability of both dyes to cross the blood–brain barrier was also assessed. At concentrations between 0.55 and 5.23 mg/L, SV47 showed a dose-dependent increase in mortality, jaw malformation, axis curvature, and edemas. At concentrations between 0.15 and 7.54 mg/L, DB14 did not have this same dose-dependence but had similar morphological outcomes at the highest doses. Nevertheless, while SV47 showed significant mortality from 4.20 mg/L, there was no significant mortality on embryos exposed to DB14. Regardless, decreased locomotor movement was observed at all concentrations of DB14, suggesting an adverse neurodevelopmental effect. Overall, our results showed that at similar concentrations, SV47 and DB14 caused different types of phenotypic effects in zebrafish embryos. Full article

(This article belongs to the Special Issue Advanced Zebrafish Model for Environmental Health Sciences Research)

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15 pages, 1497 KiB

Open AccessArticle

Teratogenic, Oxidative Stress and Behavioural Outcomes of Three Fungicides of Natural Origin (Equisetum arvense, Mimosa tenuiflora, Thymol) on Zebrafish (Danio rerio)

by Raquel Vieira, Carlos Venâncio and Luís Félix

Toxics 2021, 9(1), 8; https://doi.org/10.3390/toxics9010008 - 9 Jan 2021

Cited by 8 | Viewed by 3584

Abstract

The improper use of synthetic fungicides has raised public concerns related to environmental pollution and animal health. Over the years, plant-derived antifungals have been investigated as safer alternatives, although little scientific evidence of its neurodevelopmental effects exist. The main objective of this study [...] Read more.

The improper use of synthetic fungicides has raised public concerns related to environmental pollution and animal health. Over the years, plant-derived antifungals have been investigated as safer alternatives, although little scientific evidence of its neurodevelopmental effects exist. The main objective of this study was to explore the effects of three alternative natural extracts (Equisetum arvense, Mimosa tenuiflora, Thymol) with antifungal properties during the early development of zebrafish by evaluating different teratogenic, oxidative stress and behavioural outcomes. Following the determination of the 96 h-LC₅₀, exposure to sublethal concentrations showed the safety profile of both E. arvense and M. tenuiflora. However, following 96-h exposure to Thymol, increased lethality, pericardial oedema, yolk and eye deformations, and decreased body length were observed. The reduced and oxidized glutathione (GSH:GSSG) ratio was increased, and the glutathione-s-transferase activity in the group exposed to the highest Thymol concentration. Overall, these results support a more reducing environment associated with possible effects at the cellular proliferation level. In addition, the disruption of behavioural states (fear- and anxiety-like disorders) were noted, pointing to alterations in the c-Jun N-terminal kinase developmental signalling pathway, although further studies are required to explore this rationale. Notwithstanding, the results provide direct evidence of the teratogenic effects of Thymol, which might have consequences for non-target species. Full article

(This article belongs to the Special Issue Behavioral Impairment in Aquatic Organisms Exposed to Neurotoxic Pollutants)

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Schematic diagram of the zebrafish exposure to the plant-based fungicides. Collected embryos at around 2 h post-fertilization (hpf) were exposed to different concentrations of Equisetum arvense and Mimosa tenuiflora extracts and to Thymol for a period of 96 h. The selected concentrations varied from 1/300–1/200 to 1/3–1/2 of the determined LC50. During the exposure period, daily lethal and sublethal parameters were assessed. After 96 h exposure, eleutheroembryo were collected for biochemical screening of different biomarkers associated with oxidative stress, energetic metabolism, and neurotransmission. At 120 hpf, the locomotor activity of the eleutheroembryo was assessed using different behavioural paradigms. Full article ">Figure 2
(A) Percentages of normal, malformed and dead eleutheroembryo at the end of the exposure period (at 98 hpf). Values are presented as mean ± SD of five replicates per treatment (n = 10 random embryos per replicate). Different lowercase letters represent statistical differences among treatment groups (one-way ANOVA, p < 0.05). (B) Representative views of the malformations observed in eleutheroembryo exposed to Thymol. Malformations were observed after exposure to the highest concentration of Thymol (T3) namely as abnormal eye (e), yolk (y), and pericardiac oedema (o) and by the decreased body length (bl). The scale bar represents 500 μm. Full article ">Figure 3
(A) Heatmap of biochemical parameters measured in zebrafish eleutheroembryo at the end of the exposure to the different phyto-fungicide. Data from at least five independent samples (n = 100 individuals per replicate). The data used for the evaluation of the biochemical parameters were normalised to the control group value. Parametric data is expressed as mean ± SD and statistical analysis was performed using one-way ANOVA followed by Tukey’s multiple-comparison test. The * indicate significant differences relative to the control group (p < 0.05). (B) Star plots of A values obtained and IBRv2 value for biomarker responses of zebrafish embryos exposed for 96-h to the different plant-based fungicides. Full article ">Figure 4
Effects of the different concentrations of the phyto-fungicide on zebrafish eleutheroembryo motor behaviour. (A) Representative swimming tracks of untreated and treated zebrafish eleutheroembryo at 120 hpf. No significant changes were observed between the different treatments and the control group during the 10 min recording period. (B) Avoidance behaviour of the zebrafish eleutheroembryo in the presence of an aversive stimulus. Data is expressed as mean ± SD from five independent replicates (5 eleutheroembryo assayed for each treatment). Statistical analysis was performed using t-test: * p < 0.05, ** p < 0.01 and *** p < 0.001. (C) Distance moved during the visual motor response test. Data represent the mean distance moved during 10 min assay and is expressed as mean ± SD from five independent replicates (5 eleutheroembryo assayed for each treatment). Statistical analysis was performed using one-way ANOVA followed by Tukey’s multiple-comparison test. Different lowercase letters indicate significant differences between groups (p < 0.05). Full article ">

13 pages, 786 KiB

Open AccessArticle

An Integrated Vegetated Treatment System for Mitigating Imidacloprid and Permethrin in Agricultural Irrigation Runoff

by Bryn M. Phillips, Michael Cahn, Jennifer P. Voorhees, Laura McCalla, Katie Siegler, David L. Chambers, Thomas R. Lockhart, Xin Deng and Ron S. Tjeerdema

Toxics 2021, 9(1), 7; https://doi.org/10.3390/toxics9010007 - 9 Jan 2021

Cited by 5 | Viewed by 2695

Abstract

Pyrethroid and neonicotinoid pesticides control an array of insect pests in leafy greens, but there are concerns about the off-site movement and potential water quality impacts of these chemicals. Effective on-farm management practices can eliminate aquatic toxicity and pesticides in runoff. This project [...] Read more.

Pyrethroid and neonicotinoid pesticides control an array of insect pests in leafy greens, but there are concerns about the off-site movement and potential water quality impacts of these chemicals. Effective on-farm management practices can eliminate aquatic toxicity and pesticides in runoff. This project evaluated an integrated vegetated treatment system (VTS), including the use of polyacrylamide (PAM), for minimizing the toxicity of imidacloprid and permethrin pesticides in runoff. The VTS incorporated a sediment trap to remove coarse particles, a grass-lined ditch with compost swales to remove suspended sediment and insecticides, and granulated activated carbon (GAC) or biochar to remove residual insecticides. Runoff was sampled throughout the VTS and analyzed for pesticide concentrations, and aquatic toxicity using the midge Chironomusdilutus and the amphipod Hyalella azteca. In simulated runoff experiments, the VTS reduced suspended sediment load by 88%, and imidacloprid and permethrin load by 97% and 99%, respectively. In runoff events from a conventionally grown lettuce field, suspended sediment load was reduced by 98%, and insecticide load by 99%. Toxicity was significantly reduced in approximately half of the simulated runoff events, and most of the lettuce runoff events. Integrated vegetated treatment systems that include components for treating soluble and hydrophobic pesticides are vital tools for reducing pesticide load and occurrence of pesticide-related toxicity. Full article

(This article belongs to the Special Issue Impacts of Agrochemicals on Aquatic Ecosystems: Assessing Responses across Biological Scales)

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12 pages, 1487 KiB

Open AccessArticle

Concentrations of Persistent Organic Pollutants in Women’s Serum in the European Arctic Russia

by Yulia Varakina, Dmitry Lahmanov, Andrey Aksenov, Anna Trofimova, Rimma Korobitsyna, Natalia Belova, Nikita Sobolev, Dmitry Kotsur, Tatiana Sorokina, Andrej M. Grjibovski, Valery Chashchin and Yngvar Thomassen

Toxics 2021, 9(1), 6; https://doi.org/10.3390/toxics9010006 - 7 Jan 2021

Cited by 14 | Viewed by 3548

Abstract

Persistent organic pollutants (POPs) are heterogeneous carbon-based compounds that can seriously affect human health. The aim of this study was to measure serum concentrations of POPs in women residing in the Euro-Arctic Region of Russia. A total of 204 women from seven rural [...] Read more.

Persistent organic pollutants (POPs) are heterogeneous carbon-based compounds that can seriously affect human health. The aim of this study was to measure serum concentrations of POPs in women residing in the Euro-Arctic Region of Russia. A total of 204 women from seven rural settlements of the Nenets Autonomous Okrug (NAO) took part in the study. We measured serum concentrations of 11 polychlorinated biphenyls (PCBs) and 17 organochlorine pesticides (OCPs) across the study sites and among Nenets and non-Nenets residents. Measurement of POPs was performed using an Agilent 7890A gas chromatograph equipped with an Agilent 7000 series MS/MS triple quadrupole system. The concentrations of all POPs were low and similar to findings from other Arctic countries. However, significant geographic differences between the settlements were observed with exceptionally high concentrations of PCBs in Varnek located on Vaygach Island. Both ΣDDT (p = 0.011) and ΣPCB (p = 0.038) concentrations were significantly lower in Nenets. Our main findings suggest that the serum concentrations of the legacy POPs in women in the Euro-Arctic Region of Russia are low and similar to those in other Arctic countries. Significant variations between settlements, and between Nenets and non-Nenets residents, were found. Arctic biomonitoring research in Russia should include studies on the associations between nutrition and concentrations of POPs. Full article

(This article belongs to the Special Issue Persistent Organic Pollutants and Human Health)

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11 pages, 3465 KiB

Open AccessFeature PaperArticle

Comparative Analysis of Neurotoxicity of Six Phthalates in Zebrafish Embryos

by Cong Minh Tran, Trinh Ngoc Do and Ki-Tae Kim

Toxics 2021, 9(1), 5; https://doi.org/10.3390/toxics9010005 - 7 Jan 2021

Cited by 40 | Viewed by 5563

Abstract

The effects and underlying mechanisms of phthalates on neurotoxicity remain unclear as compared with the potentials of these substances as endocrine disruptors. The locomotor activities of zebrafish embryos were investigated upon exposure to six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl [...] Read more.

The effects and underlying mechanisms of phthalates on neurotoxicity remain unclear as compared with the potentials of these substances as endocrine disruptors. The locomotor activities of zebrafish embryos were investigated upon exposure to six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBzP), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DnOP), and diisononyl phthalate (DiNP). Moreover, changes in fluorescence intensity in the green fluorescent protein (GFP) transgenic (Tg) lines Tg(HuC:eGFP), Tg(sox10:eGFP), and Tg(mbp:GFP) were measured after exposure to six phthalates, and changes in the expression profiles of genes involved in the cholinergic (ache) and dopaminergic systems (dat, th, and drd1b) were assessed. Exposure to BBzP, DEHP, and DiNP affected larval behaviors, whereas exposure to DMP, DEP, and DnOP revealed no alterations. A reduced expression of Tg(HuC:eGFP) was observed upon exposure to BBzP, DEHP, and DiNP. The expression of Tg(sox10:eGFP) and Tg(mbp:GFP) was reduced only in response to BBzP and DiNP, respectively. Further, exposure to DiNP upregulated ache and drd1b. The upregulation of ache and downregulation of drd1b was observed in DEHP-exposed groups. Exposure to BBzP suppressed th expression. These observations indicate that exposure to phthalates impaired embryogenesis of the neurological system and neurochemicals in zebrafish embryos, although the detailed mechanisms varied among the individual phthalates. Further mechanistic studies are needed to better understand the causality between phthalate exposure and neurotoxicity. Full article

(This article belongs to the Special Issue Advanced Zebrafish Model for Environmental Health Sciences Research)

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Locomotor responses of larval zebrafish (n = 48) upon exposure to diisononyl phthalate (BBzP) (A,B), di-2-ethylhexyl phthalate (DEHP) (C,D), and benzyl butyl phthalate (DiNP) (E,F). Locomotor response was divided into the dark (A,C,E) and light phase (B,D,F) for each phthalate. (<tt>↑</tt>) represents a significant hyperactivity compared with control and (<tt>↓</tt>) indicates a significant hypoactivity compared with control. (* p < 0.05; ** p < 0.01). Dist: distance. Dur: duration. The attention is needed on different scale of total distance in each graph. Full article ">Figure 2
FIs of Tg(huc:EGFP), Tg(sox10:EGFP), and Tg(mbp:GFP) for BBzP (A), DEHP (B), and DiNP (C). FI was averaged from 10 images/treatment. Values are expressed as the mean ± SEM. * p < 0.05. Full article ">Figure 3
Representative images of Tg(HuC:EGFP), Tg(sox10:EGFP), and Tg(mbp:GFP) in untreated controls and embryos treated with BBzP, DEHP, and DiNP at 10 K μg/L. Full article ">Figure 4
Fold change to expression levels of ache, dat, drd1b, and th in zebrafish larvae exposed to BBzP (A), DEHP (B), and DiNP (C) at concentrations of 5, 50, and 500 μg/L. Values are expressed as the mean ± SEM. * p < 0.05. Full article ">

11 pages, 1230 KiB

Open AccessFeature PaperReview

Commonalities between Copper Neurotoxicity and Alzheimer’s Disease

by Roshni Patel and Michael Aschner

Toxics 2021, 9(1), 4; https://doi.org/10.3390/toxics9010004 - 7 Jan 2021

Cited by 45 | Viewed by 5924

Abstract

Alzheimer’s disease, a highly prevalent form of dementia, targets neuron function beginning from the hippocampal region and expanding outwards. Alzheimer’s disease is caused by elevated levels of heavy metals, such as lead, zinc, and copper. Copper is found in many areas of daily [...] Read more.

Alzheimer’s disease, a highly prevalent form of dementia, targets neuron function beginning from the hippocampal region and expanding outwards. Alzheimer’s disease is caused by elevated levels of heavy metals, such as lead, zinc, and copper. Copper is found in many areas of daily life, raising a concern as to how this metal and Alzheimer’s disease are related. Previous studies have not identified the common pathways between excess copper and Alzheimer’s disease etiology. Our review corroborates that both copper and Alzheimer’s disease target the hippocampus, cerebral cortex, cerebellum, and brainstem, affecting motor skills and critical thinking. Additionally, Aβ plaque formation was analyzed beginning from synthesis at the APP parent protein site until Aβ plaque formation was completed. Structural changes were also noted. Further analysis revealed a relationship between amyloid-beta plaques and copper ion concentration. As copper ion levels increased, it bound to the Aβ monomer, expediting the plaque formation process, and furthering neurodegeneration. These conclusions can be utilized in the medical community to further research on the etiology of Alzheimer’s disease and its relationships to copper and other metal-induced neurotoxicity. Full article

(This article belongs to the Special Issue Neurotoxicity of Environmental Metal Toxicants)

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11 pages, 1978 KiB

Open AccessArticle

Paternal Biomass Smoke Exposure in Rats Produces Behavioral and Cognitive Alterations in the Offspring

by Larisa M. Sosedova, Vera A. Vokina, Mikhail A. Novikov, Viktor S. Rukavishnikov, Elizaveta S. Andreeva, Olga M. Zhurba and Anton N. Alekseenko

Toxics 2021, 9(1), 3; https://doi.org/10.3390/toxics9010003 - 31 Dec 2020

Cited by 13 | Viewed by 4359

Abstract

Particular concern at the present stage is the health effects of wildfires’ smoke. The aim of the study was to determine the impact of paternal biomass-smoke exposure on offspring’s behavior and cognitive abilities. Male rats were exposed to biomass smoke for four hours/day, five [...] Read more.

Particular concern at the present stage is the health effects of wildfires’ smoke. The aim of the study was to determine the impact of paternal biomass-smoke exposure on offspring’s behavior and cognitive abilities. Male rats were exposed to biomass smoke for four hours/day, five days/week, for four weeks. Average concentration of carbon monoxide and particulate matter of 2.5 μm PM_2.5 in the chamber during exposure were 28.7 ± 5.3 mg/m³ and 1.9 ± 0.5 mg/m³, respectively. At the same time, high concentrations of furfural and acetaldehyde were detected in the air environment of the exposure chambers. Offspring was obtained by mating of experimental males with untreated females, immediately after the end of the exposure and after 60 days (long-term period). Offspring were tested by using the Morris water maze and open field at three months of age. Male and female offspring born by mating immediately after exposure demonstrated decreased exploratory behavior, locomotor activity, and spatial navigation, as well as increased anxiety levels. Locomotor and exploratory activity in rats of both sexes from progeny obtained after long-term exposure to smoke had no statistically significant differences when compared to the control; however, the females showed a high level of anxiety and impaired cognitive functions. The recovery period after biomass-smoke intoxication, comparable in duration of spermatogenesis in rats, was an important factor in reducing the risk of developing central nervous system (CNS) disorders in offspring. Full article

(This article belongs to the Special Issue Developmental Environmental Exposures, Epigenetics and Long-Term Health)

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Design of the experimental study. Experimental design: Male rats were exposed to biomass smoke (4 hours/day, 5 days/week, for 4 weeks). Exposed or control males were mated with unexposed female rats, to generate the offspring: immediately after exposure and after 60 days (long-term period). Behavior and cognitive abilities of offspring born by mating immediately after exposure (F1 (1)) and offspring born by mating in the long-term period after exposure (F1 (2)) were assessed. Full article ">Figure 2
Chromatogram of the components selected by the SPME method. Identified components: (1) Hexanal, (2) furfural, (3) α-Pinene, (4) Camphene, (5) methylfuraldehyde, (6) 3-carene, (7) p-cymene, (8) D-limonene, (9) o-Guaiacol, (10) levoglucosenone, (11) Borneol, (12) Creosol, (13) Berbenone, (14) Longifoline, (15) γ-Muurolene, (16) α-Muurolene, (17) γ-Cadinene, (18) δ-Cadinene, (19) α-Cadinene, and (20) α-Calacorene. Full article ">Figure 3
Chromatogram of derivatized aldehydes PFBHA. Identified components: (1) formaldehyde, (2) acetaldehyde, (3) acetone, (4) propionic aldehyde, (5) isobutyl aldehyde, (6) butyl aldehyde, (7) diacetyl, (8) valerian aldehyde, (9) hexanal, and (10) furfural. Full article ">Figure 4
Test results in the Morris water maze. Offspring born by mating immediately after exposure. Note: * the differences statistically significant compared to the control at p < 0.05. Full article ">Figure 5
Test results in the Morris water maze. Offspring born by mating in the long-term period after exposure. Full article ">Figure 6
Test results in the Morris water maze. Number of animals that completed and failed the test. Note: * the differences statistically significant compared to the control at p < 0.05. Full article ">

11 pages, 6613 KiB

Open AccessArticle

Biosynthesized Iron Oxide Nanoparticles (Fe₃O₄ NPs) Mitigate Arsenic Toxicity in Rice Seedlings

by Sehresh Khan, Nazneen Akhtar, Shafiq Ur Rehman, Shaukat Shujah, Eui Shik Rha and Muhammad Jamil

Toxics 2021, 9(1), 2; https://doi.org/10.3390/toxics9010002 - 31 Dec 2020

Cited by 56 | Viewed by 6190

Abstract

Arsenic (As) contamination has emerged as a serious public health concern worldwide because of its accumulation and mobility through the food chain. Therefore, the current study was planned to check the effect of Bacillus subtilis-synthesized iron oxide nano particles (Fe₃O [...] Read more.

Arsenic (As) contamination has emerged as a serious public health concern worldwide because of its accumulation and mobility through the food chain. Therefore, the current study was planned to check the effect of Bacillus subtilis-synthesized iron oxide nano particles (Fe₃O₄ NP) on rice (Oryza Sativa L.) growth against arsenic stress (0, 5, 10 and 15 ppm). Iron oxide nanoparticles were extracellular synthesized from Bacillus subtilis with a desired shape and size. The formations of nanoparticles were differentiated through UV-Visible Spectroscopy, FTIR, XRD and SEM. The UV-Visible spectroscopy of Bacillus subtilis-synthesized nanoparticles showed that the iron oxide surface plasmon band occurs at 268 nm. FTIR results revealed that different functional groups (aldehyde, alkene, alcohol and phenol) were present on the surface of nanoparticles. The SEM image showed that particles were spherical in shape with an average size of 67.28 nm. Arsenic toxicity was observed in seed germination and young seedling stage. The arsenic application significantly reduced seed germination (35%), root and shoots length (1.25 and 2.00 cm), shoot/root ratio (0.289), fresh root and shoots weight (0.205 and 0.260 g), dry root and shoots weight (6.55 and 6.75 g), dry matter percentage of shoot (12.67) and root (14.91) as compared to control. Bacillus subtilis-synthesized Fe₃O₄ NPs treatments (5 ppm) remarkably increased the germination (65%), root and shoot length (2 and 3.45 cm), shoot/root ratio (1.24) fresh root and shoot weight (0.335 and 0.275 mg), dry root and shoot weight (11.75 and 10.6 mg) and dry matter percentage of shoot (10.40) and root (18.37). Results revealed that the application of Fe₃O₄ NPs alleviated the arsenic stress and enhanced the plant growth. This study suggests that Bacillus subtilus-synthesized iron oxide nanoparticles can be used as nano-adsorbents in reducing arsenic toxicity in rice plants. Full article

(This article belongs to the Special Issue Heavy Metal Toxicity Effects on Plants)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Representative UV-Vis absorption spectra (a), XRD pattern (b), FTIR spectra (c), SEM image, 0.5 µm scale (d) of iron oxide nanoparticles synthesized by adding 15 mL of iron oxide suspension with 5 mL of Bacillus subtilus extract. Full article ">Figure 2
Effect of Bacillus subtilis-synthesized Fe3O4 NPs on “seed germination (%)” of rice (Oryza sativa L.) in arsenic-contaminated water. Different letters show a significant difference at p < 0.05 between treatment. Full article ">Figure 3
Effect of Bacillus subtilis-synthesized Fe3O4 NPs on shoot length of rice (Oryza sativa L.) in arsenic-contaminated water. Different letters show a significant difference at p < 0.05 between treatments. Full article ">Figure 4
Effect of Bacillus subtilis-synthesized Fe3O4 NPs on root length of rice (Oryza sativa L.) in arsenic-contaminated water. Different letters show a significant difference at p < 0.05 between treatments. Full article ">Figure 5
Effect of Bacillus subtilis-synthesized Fe3O4 NPs on shoot/root ratio of rice (Oryza sativa L.) in arsenic-contaminated water. Different letters show a significant difference at p < 0.05 between treatments. Full article ">Figure 6
Effect of Bacillus subtilis-synthesized Fe3O4 NPs on (a) fresh shoot (b) fresh root weight and (c) dry shoot (d) dry root weight of rice (Oryza sativa L.) in arsenic-contaminated water. Different letters show a significant difference at p < 0.05 between treatments. Full article ">Figure 7
Effect of Bacillus subtilis-synthesized Fe3O4 NPs on (a) shoot (b) root dry matter % of rice (Oryza sativa L.) in arsenic-contaminated water. Different letters show a significant difference at p < 0.05 between treatments. Full article ">

14 pages, 3269 KiB

Open AccessCommunication

Changes in the Population Size of Calbindin D-28k-Immunoreactive Enteric Neurons in the Porcine Caecum under the Influence of Bisphenol A: A Preliminary Study

by Ignacy Gonkowski, Slawomir Gonkowski, Ewa Dzika and Joanna Wojtkiewicz

Toxics 2021, 9(1), 1; https://doi.org/10.3390/toxics9010001 - 28 Dec 2020

Cited by 3 | Viewed by 2139

Abstract

Calbindin D-28k (CB) is a calcium-binding protein widely distributed in living organisms that may act as a calcium buffer and sensory protein. CB is present in the enteric nervous system (ENS) situated in the gastrointestinal tract, which controls the majority of activities of [...] Read more.

Calbindin D-28k (CB) is a calcium-binding protein widely distributed in living organisms that may act as a calcium buffer and sensory protein. CB is present in the enteric nervous system (ENS) situated in the gastrointestinal tract, which controls the majority of activities of the stomach and intestine. The influence of various doses of bisphenol A (BPA)—a chemical compound widely used in plastics production—on the number and distribution of CB-positive enteric neuronal cells in the porcine caecum was investigated with an immunofluorescence technique. The obtained results showed that low dosages of BPA resulted in an increase in the number of CB-positive neuronal cells in the myenteric (MP) and inner submucous (ISP) plexuses, whereas it did not alter the number of such neuronal cells in the outer submucous plexus (OSP). High dosages of BPA caused the increase in the amount of CB-positive perikarya in all the above-mentioned kinds of the caecal neuronal plexuses. These observations strongly suggest that CB in the ENS participates in the processes connected with the toxic activity of BPA. Most likely, the changes noted in this experiment result from the adaptive and protective properties of CB. Full article

(This article belongs to the Section Toxicology)

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Figure 1
The enteric nervous system in the caecum of the domestic pig shown by labeling with pan-neuronal marker protein gene product 9.5 (PGP 9.5): ML: mucosal layer, ISP: inner submucous plexus, SML: submucosal layer, OSP: outer submucous plexus, CML: circular muscular layer, MP: myenteric plexus and LML: longitudinal muscular layer. Scale bar: 100 µm. Full article ">Figure 2
Visualization of the impact of bisphenol A (BPA) on the percentage of calbindin D-28k-immunoreactive enteric neuronal cells in the myenteric (MP), outer submucous (OSP) and inner submucous (ISP) plexuses in the porcine caecum. Full article ">Figure 3
Myenteric plexus (A), outer submucous plexus (B) and inner submucous plexus (C) in the porcine caecum in control animals (I) and animals treated with low (II) and high (III) doses of bisphenol A, labeled against pan-neuronal marker PGP 9.5 (green) and calbindin (red). Calbindin-positive neurons are indicated with arrows. Scale bar: 50 µm. Full article ">Figure 4
Myenteric plexus in the porcine caecum in control animals (I) and animals treated with low (II) and high (III) doses of bisphenol A, labeled against pan-neuronal marker PGP 9.5 (green), calbindin (red) and a marker of cell nuclei-4′,6-diamidino-2-phenylindole (DAPI) (blue). Calbindin-positive neurons are indicated with arrows. Scale bar: 50 µm. Full article ">Figure 5
Visualization of the impact of BPA on the total population of the enteric neuronal cells (immunoreactive to PGP 9.5) in the myenteric (MP), outer submucous (OSP) and inner submucous (ISP) plexuses in the porcine caecum. Full article ">

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Toxics, Volume 9, Issue 1 (January 2021) – 16 articles

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