Toxics

15 pages, 1210 KiB

Open AccessFeature PaperArticle

Salinity Alters Toxicity of Commonly Used Pesticides in a Model Euryhaline Fish Species (Menidia beryllina)

by Sara J. Hutton, Scott J. St. Romain, Emily I. Pedersen, Samreen Siddiqui, Patrick E. Chappell, J. Wilson White, Kevin L. Armbrust and Susanne M. Brander

Toxics 2021, 9(5), 114; https://doi.org/10.3390/toxics9050114 - 20 May 2021

Cited by 15 | Viewed by 3986

Abstract

Changing salinity in estuaries due to sea level rise and altered rainfall patterns, as a result of climate change, has the potential to influence the interactions of aquatic pollutants as well as to alter their toxicity. From a chemical property point of view, [...] Read more.

Changing salinity in estuaries due to sea level rise and altered rainfall patterns, as a result of climate change, has the potential to influence the interactions of aquatic pollutants as well as to alter their toxicity. From a chemical property point of view, ionic concentration can increase the octanol–water partition coefficient and thus decrease the water solubility of a compound. Biologically, organism physiology and enzyme metabolism are also altered at different salinities with implications for drug metabolism and toxic effects. This highlights the need to understand the influence of salinity on pesticide toxicity when assessing risk to estuarine and marine fishes, particularly considering that climate change is predicted to alter salinity regimes globally and many risk assessments and regulatory decisions are made using freshwater studies. Therefore, we exposed the Inland Silverside (Menidia beryllina) at an early life stage to seven commonly used pesticides at two salinities relevant to estuarine waters (5 PSU and 15 PSU). Triadimefon was the only compound to show a statistically significant increase in toxicity at the 15 PSU LC₅₀. However, all compounds showed a decrease in LC₅₀ values at the higher salinity, and all but one showed a decrease in the LC₁₀ value. Many organisms rely on estuaries as nurseries and increased toxicity at higher salinities may mean that organisms in critical life stages of development are at risk of experiencing adverse, toxic effects. The differences in toxicity demonstrated here have important implications for organisms living within estuarine and marine ecosystems in the Anthropocene as climate change alters estuarine salinity regimes globally. 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

19 pages, 3987 KiB

Open AccessArticle

Synergistic Effects of Zinc Oxide Nanoparticles and Bacteria Reduce Heavy Metals Toxicity in Rice (Oryza sativa L.) Plant

by Nazneen Akhtar, Sehresh Khan, Shafiq Ur Rehman, Zia Ur Rehman, Amana Khatoon, Eui Shik Rha and Muhammad Jamil

Toxics 2021, 9(5), 113; https://doi.org/10.3390/toxics9050113 - 20 May 2021

Cited by 51 | Viewed by 4419

Abstract

Heavy metals (HMs) are toxic elements which contaminate the water bodies in developing countries because of their excessive discharge from industrial zones. Rice (Oryza sativa L) crops are submerged for a longer period of time in water, so irrigation with HMs polluted [...] Read more.

Heavy metals (HMs) are toxic elements which contaminate the water bodies in developing countries because of their excessive discharge from industrial zones. Rice (Oryza sativa L) crops are submerged for a longer period of time in water, so irrigation with HMs polluted water possesses toxic effects on plant growth. This study was initiated to observe the synergistic effect of bacteria (Bacillus cereus and Lysinibacillus macroides) and zinc oxide nanoparticles (ZnO NPs) (5, 10, 15, 20 and 25 mg/L) on the rice that were grown in HMs contaminated water. Current findings have revealed that bacteria, along with ZnO NPs at lower concentration, showed maximum removal of HMs from polluted water at pH 8 (90 min) as compared with higher concentrations. Seeds primed with bacteria grown in HM polluted water containing ZnO NPs (5 mg/L) showed reduced uptake of HMs in root, shoot and leaf, thus resulting in increased plant growth. Furthermore, their combined effects also reduced the bioaccumulation index and metallothionine (MTs) content and enhanced the tolerance index of plants. This study suggested that synergistic treatment of bacteria with lower concentrations of ZnO NPs helped plants to reduce heavy metal toxicity, especially Pb and Cu, and enhanced plant growth. Full article

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

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11 pages, 3540 KiB

Open AccessCommunication

Toxic Effects of Docosahexaenoic Acid Treatment in the Rat Liver BRL-3A Cell

by Wenli Luo, Li Li, Weina Xu, Jing Zhang and Jianxiong Xu

Toxics 2021, 9(5), 112; https://doi.org/10.3390/toxics9050112 - 20 May 2021

Cited by 1 | Viewed by 2351

Abstract

The cytotoxicity of docosahexaenoic acid (DHA) on normal cells is still unclear. This study investigated the effects of DHA on the cytotoxicity and possible mechanism in the BRL-3A cell. The cultured rat liver BRL-3A cell line was treated with 50, 100 and 200 [...] Read more.

The cytotoxicity of docosahexaenoic acid (DHA) on normal cells is still unclear. This study investigated the effects of DHA on the cytotoxicity and possible mechanism in the BRL-3A cell. The cultured rat liver BRL-3A cell line was treated with 50, 100 and 200 μM DHA for 24 h. The cell viability was increased in the 50 and 100 μM DHA treatments, but decreased in the 200 μM DHA treatment. The 50, 100 and 200 μM DHA treatments increased the proportion of the apoptotic cells, the levels of lactate dehydrogenase (LDH), alkaline phosphatase (AKP) and IL-6 in the supernatant, and the ratio of the phosphonated p38MAPK to the p38MAPK (p-p38/p38) protein in the cells. The expression of TGF beta-activated kinase 1 (TAK1), nuclear transcription factor-κB p65 (NF-κB p65) and the inhibitor of NF-κB alpha (IκBα) mRNA, and the ratio of the phosphonated IκBα (p-IκBα) to IκBα protein were increased in the 200 μM DHA treatment, while the ratio of phosphonated extracellular regulated protein kinases (p-ERK) to ERK protein was decreased in the 200 μM DHA treatment. These results indicate that DHA-treated (50, 100 and 200 μM) BRL-3A cells for 24 h promotes cell apoptosis and inflammatory response, and the p38 MAPK, ERK and NF-κB signal pathways were involved in mediating the apoptosis and inflammatory response. Full article

(This article belongs to the Section Toxicology)

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17 pages, 4539 KiB

Open AccessArticle

Full Factorial Design for Gold Recovery from Industrial Solutions

by Maria Mihăilescu, Adina Negrea, Mihaela Ciopec, Petru Negrea, Narcis Duțeanu, Ion Grozav, Paula Svera, Cosmin Vancea, Alina Bărbulescu and Cristian Ștefan Dumitriu

Toxics 2021, 9(5), 111; https://doi.org/10.3390/toxics9050111 - 20 May 2021

Cited by 14 | Viewed by 3323

Abstract

Gold is one of the precious metals with multiple uses, whose deposits are much smaller than the global production needs. Therefore, extracting maximum gold quantities from industrial diluted solutions is a must. Am-L-GA is a new material, obtained by an Amberlite XAD7-type commercial [...] Read more.

Gold is one of the precious metals with multiple uses, whose deposits are much smaller than the global production needs. Therefore, extracting maximum gold quantities from industrial diluted solutions is a must. Am-L-GA is a new material, obtained by an Amberlite XAD7-type commercial resin, functionalized through saturation with L-glutamic acid, whose adsorption capacity has been proved to be higher than those of other materials utilized for gold adsorption. In this context, this article presents the results of a factorial design experiment for optimizing the gold recovery from residual solutions resulting from the electronics industry using Am-L-GA. Firstly, the material was characterized using atomic force microscopy (AFM), to emphasize the material’s characteristics, essential for the adsorption quality. Then, the study showed that among the parameters taken into account in the analysis (pH, temperature, initial gold concentration, and contact time), the initial gold concentration in the solution plays a determinant role in the removal process and the contact time has a slightly positive effect, whereas the pH and temperature do not influence the adsorption capacity. The maximum adsorption capacity of 29.27 mg/L was obtained by optimizing the adsorption process, with the control factors having the following values: contact time ~106 min, initial Au(III) concentration of ~164 mg/L, pH = 4, and temperature of 25 °C. It is highlighted that the factorial design method is an excellent instrument to determine the effects of different factors influencing the adsorption process. The method can be applied for any adsorption process if it is necessary to reduce the number of experiments, to diminish the resources or time consumption, or for expanding the investigation domain above the experimental limits. Full article

(This article belongs to the Special Issue Statistical Assessment, Modeling, and Mitigation of Water and Soil Pollution)

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8 pages, 736 KiB

Open AccessCommunication

Increased PACAP- and DβH-Positive Hepatic Nerve Fibers after Bisphenol A Exposure

by Michael Thoene, Liliana Rytel, Ewa Dzika and Joanna Wojtkiewicz

Toxics 2021, 9(5), 110; https://doi.org/10.3390/toxics9050110 - 18 May 2021

Cited by 3 | Viewed by 1761

Abstract

Bisphenol A (BPA) is an endocrine-disrupting compound (EDC) that can be found nearly everywhere in our polluted world. BPA has been correlated with pathophysiologies that include psychological disorders, especially in children. This study used juvenile porcine models to investigate the effects of BPA [...] Read more.

Bisphenol A (BPA) is an endocrine-disrupting compound (EDC) that can be found nearly everywhere in our polluted world. BPA has been correlated with pathophysiologies that include psychological disorders, especially in children. This study used juvenile porcine models to investigate the effects of BPA on the liver of developing vertebrates in order to determine the effects of BPA on innervated hepatic samples with the use of double-labeled immunofluorescence. This study specifically investigated the sympathetic nervous system (SNS) colocalized with a specific neural marker (PACAP) that has previously been correlated with specific pathophysiologies in the literature. In the liver, it was observed that there were significantly increased nerve fibers in the SNS colocalized with the neural marker PACAP after exposure to BPA at concentrations considered to be “safe” with the same or more profound effects at higher exposure levels. The implications of childhood exposure to BPA are then discussed with regard to several correlation studies that have linked BPA exposure to behavioral/psychological disorders. It is possible that BPA exposure in childhood may upregulate the SNS and PACAP levels, thereby contributing to the correlations in the literature. Full article

(This article belongs to the Special Issue Effects of Food Contaminants on Human Health)

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8 pages, 652 KiB

Open AccessPerspective

Are Honey Bees at Risk from Microplastics?

by Yahya Al Naggar, Markus Brinkmann, Christie M. Sayes, Saad N. AL-Kahtani, Showket A. Dar, Hesham R. El-Seedi, Bernd Grünewald and John P. Giesy

Toxics 2021, 9(5), 109; https://doi.org/10.3390/toxics9050109 - 15 May 2021

Cited by 39 | Viewed by 8314

Abstract

Microplastics (MPs) are ubiquitous and persistent pollutants, and have been detected in a wide variety of media, from soils to aquatic systems. MPs, consisting primarily of polyethylene, polypropylene, and polyacrylamide polymers, have recently been found in 12% of samples of honey collected in [...] Read more.

Microplastics (MPs) are ubiquitous and persistent pollutants, and have been detected in a wide variety of media, from soils to aquatic systems. MPs, consisting primarily of polyethylene, polypropylene, and polyacrylamide polymers, have recently been found in 12% of samples of honey collected in Ecuador. Recently, MPs have also been identified in honey bees collected from apiaries in Copenhagen, Denmark, as well as nearby semiurban and rural areas. Given these documented exposures, assessment of their effects is critical for understanding the risks of MP exposure to honey bees. Exposure to polystyrene (PS)-MPs decreased diversity of the honey bee gut microbiota, followed by changes in gene expression related to oxidative damage, detoxification, and immunity. As a result, the aim of this perspective was to investigate whether wide-spread prevalence of MPs might have unintended negative effects on health and fitness of honey bees, as well as to draw the scientific community’s attention to the possible risks of MPs to the fitness of honey bees. Several research questions must be answered before MPs can be considered a potential threat to bees. Full article

(This article belongs to the Special Issue Underexplored Chemical Interactions in Humans and Wildlife)

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12 pages, 1639 KiB

Open AccessArticle

Short-Term Exposure to Ambient Air Pollution and Increased Emergency Room Visits for Skin Diseases in Beijing, China

by Wanzhou Wang, Wenlou Zhang, Jingjing Zhao, Hongyu Li, Jun Wu, Furong Deng, Qingbian Ma and Xinbiao Guo

Toxics 2021, 9(5), 108; https://doi.org/10.3390/toxics9050108 - 12 May 2021

Cited by 17 | Viewed by 3059

Abstract

Skin diseases have become a global concern. This study aims to evaluate the associations between ambient air pollution and emergency room visits for skin diseases under the background of improving air quality in China. Based on 45,094 cases from a general hospital and [...] Read more.

Skin diseases have become a global concern. This study aims to evaluate the associations between ambient air pollution and emergency room visits for skin diseases under the background of improving air quality in China. Based on 45,094 cases from a general hospital and fixed-site monitoring environmental data from 2014–2019 in Beijing, China, this study used generalized additive models with quasi-Poisson regression to estimate the exposure–health associations at lag 0–1 to lag 0–7. PM_2.5 and NO₂ exposure were associated with increased emergency room visits for total skin diseases (ICD10: L00-L99). Positive associations of PM_2.5, PM₁₀, O₃ and NO₂ with dermatitis/eczema (ICD-10: L20–30), as well as SO₂ and NO₂ with urticaria (ICD-10: L50) visits were also found. For instance, a 10 μg/m³ increase in PM_2.5 was associated with increases of 0.7% (95%CI: 0.2%, 1.2%) in total skin diseases visits at lag 0–5 and 1.1% (95%CI: 0.6%, 1.7%) in dermatitis/eczema visits at lag 0–1, respectively. For PM_2.5, PM₁₀ and CO, stronger annual associations were typically observed in the high-pollution (2014) and low-pollution (2018/2019) years. For instance, a 10 μg/m³ increase in PM_2.5 at lag 0–5 was associated with increases of 1.8% (95%CI: 1.0%, 2.6%) and 2.3% (95%CI: 0.4%, 4.3%) in total skin disease visits in 2014 and 2018, respectively. Our study emphasizes the necessity of controlling the potential health hazard of air pollutants on skin, although significant achievements in air quality control have been made in China. Full article

(This article belongs to the Special Issue Integrated Effects of Air Pollutions and Climate Change on Human Health)

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17 pages, 4703 KiB

Open AccessArticle

Clastogenicity and Aneugenicity of 1,4-Benzoquinone in Different Lineages of Mouse Hematopoietic Stem/Progenitor Cells

by Paik Wah Chow, Zariyantey Abd Hamid, Ramya Dewi Mathialagan, Nor Fadilah Rajab, Salwati Shuib and Sarina Sulong

Toxics 2021, 9(5), 107; https://doi.org/10.3390/toxics9050107 - 12 May 2021

Cited by 6 | Viewed by 2351

Abstract

Previous reports on hematotoxicity and leukemogenicity related to benzene exposure highlighted its adverse effects on hematopoiesis. Despite the reported findings, studies concerning the mechanism of benzene affecting chromosomal integrity in lineage-committed hematopoietic stem/progenitor cells (HSPCs) remain unclear. Here, we studied the clastogenicity and [...] Read more.

Previous reports on hematotoxicity and leukemogenicity related to benzene exposure highlighted its adverse effects on hematopoiesis. Despite the reported findings, studies concerning the mechanism of benzene affecting chromosomal integrity in lineage-committed hematopoietic stem/progenitor cells (HSPCs) remain unclear. Here, we studied the clastogenicity and aneugenicity of benzene in lineage-committed HSPCs via karyotyping. Isolated mouse bone marrow cells (MBMCs) were exposed to the benzene metabolite 1,4-benzoquinone (1,4-BQ) at 1.25, 2.5, 5, 7, and 12 μM for 24 h, followed by karyotyping. Then, the chromosomal aberration (CA) in 1,4-BQ-exposed hematopoietic progenitor cells (HPCs) comprising myeloid, Pre-B lymphoid, and erythroid lineages were evaluated following colony-forming cell (CFC) assay. Percentage of CA, predominantly via Robertsonian translocation (Rb), was increased significantly (p < 0.05) in MBMCs and all progenitors at all concentrations. As a comparison, Pre-B lymphoid progenitor demonstrated a significantly higher percentage of CA (p < 0.05) than erythroid progenitor at 1.25, 2.5, and 7 μM as well as a significantly higher percentage (p < 0.05) than myeloid progenitor at 7 μM of 1,4-BQ. In conclusion, 1,4-BQ induced CA, particularly via Rb in both MBMCs and HPCs, notably via a lineage-dependent response. The role of lineage specificity in governing the clastogenicity and aneugenicity of 1,4-BQ deserves further investigation. Full article

(This article belongs to the Section Toxicology)

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11 pages, 2794 KiB

Open AccessArticle

Perfluoroalkylated Substances (PFAS) Associated with Microplastics in a Lake Environment

by John W. Scott, Kathryn G. Gunderson, Lee A. Green, Richard R. Rediske and Alan D. Steinman

Toxics 2021, 9(5), 106; https://doi.org/10.3390/toxics9050106 - 11 May 2021

Cited by 48 | Viewed by 8832

Abstract

The presence of both microplastics and per- and polyfluoroalkyl substances (PFAS) is ubiquitous in the environment. The ecological impacts associated with their presence are still poorly understood, however, these contaminants are extremely persistent. Although plastic in the environment can concentrate pollutants, factors such [...] Read more.

The presence of both microplastics and per- and polyfluoroalkyl substances (PFAS) is ubiquitous in the environment. The ecological impacts associated with their presence are still poorly understood, however, these contaminants are extremely persistent. Although plastic in the environment can concentrate pollutants, factors such as the type of plastic and duration of environmental exposure as it relates to the degree of adsorption have received far less attention. To address these knowledge gaps, experiments were carried out that examined the interactions of PFAS and microplastics in the field and in a controlled environment. For field experiments, we measured the abundance of PFAS on different polymer types of microplastics that were deployed in a lake for 1 month and 3 months. Based on these results, a controlled experiment was conducted to assess the adsorption properties of microplastics in the absence of associated inorganic and organic matter. The adsorption of PFAS was much greater on the field-incubated plastic than what was observed in the laboratory with plastic and water alone, 24 to 259 times versus one-seventh to one-fourth times background levels. These results suggest that adsorption of PFAS by microplastics is greatly enhanced by the presence of inorganic and/or organic matter associated with these materials in the environment, and could present an environmental hazard for aquatic biota. Full article

(This article belongs to the Special Issue Microplastics in Aquatic Environments: Occurrence, Distribution and Effects)

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15 pages, 8388 KiB

Open AccessArticle

In-Vitro and In-Vivo Tolerance and Therapeutic Investigations of Phyto-Fabricated Iron Oxide Nanoparticles against Selected Pathogens

by Amreen Shah, Isfahan Tauseef, Manel Ben Ali, Muhammad Arfat Yameen, Amine Mezni, Amor Hedfi, Syed Kashif Haleem and Sirajul Haq

Toxics 2021, 9(5), 105; https://doi.org/10.3390/toxics9050105 - 8 May 2021

Cited by 20 | Viewed by 2871

Abstract

The Paeonia emodi (P. emodi)-mediated iron oxide nanoparticles (Fe₂O₃ NPs) were screened for in-vitro and in-vivo antibacterial activity against the Staphylococcus aureus (S. aureus) (ATCC #: 6538) and Escherichia coli (E. coli) (ATCC #:15224). [...] Read more.

The Paeonia emodi (P. emodi)-mediated iron oxide nanoparticles (Fe₂O₃ NPs) were screened for in-vitro and in-vivo antibacterial activity against the Staphylococcus aureus (S. aureus) (ATCC #: 6538) and Escherichia coli (E. coli) (ATCC #:15224). The synthesized Fe₂O₃ NPs were characterized via nitrogen adsorption-desorption process, X-ray diffractometer (XRD), transmission and scanning electron microscopies (TEM and SEM), energy dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopies. The S_BET was found to be 94.65 m²/g with pore size of 2.99 nm, whereas the average crystallite and particles size are 23 and 27.64 nm, respectively. The 4 μg/mL is the MIC that inhibits the growth of E. coli, whereas those for S. aureus are below the detection limit (<1.76 μg/mL). The tolerance limit of the mice model was inspected by injecting different concentration of Fe₂O₃ NPs and bacteria suspensions. The 14 ppm suspension was the tolerated dose and the concentration above were proved lethal. The most severe infection was induced in mice with injection of 3 × 10⁷ CFUs of both bacteria, while the inoculation of higher concentrations of bacterial suspensions resulted in the mice’s death. The histopathological and hematological studies reveals that the no/negligible infection was found in the mice exposed to the simultaneous inoculation of Fe₂O₃ NPs (14 ppm) and bacterial suspensions (3 × 10⁷ CFUs). Full article

(This article belongs to the Collection Environmental and Health Risks of Nanotechnology)

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17 pages, 3995 KiB

Open AccessArticle

Assessing Combined Effects for Mixtures of Similar and Dissimilar Acting Neuroactive Substances on Zebrafish Embryo Movement

by Afolarin O. Ogungbemi, Riccardo Massei, Rolf Altenburger, Stefan Scholz and Eberhard Küster

Toxics 2021, 9(5), 104; https://doi.org/10.3390/toxics9050104 - 6 May 2021

Cited by 7 | Viewed by 3108

Abstract

Risk assessment of chemicals is usually conducted for individual chemicals whereas mixtures of chemicals occur in the environment. Considering that neuroactive chemicals are a group of contaminants that dominate the environment, it is then imperative to understand the combined effects of mixtures. The [...] Read more.

Risk assessment of chemicals is usually conducted for individual chemicals whereas mixtures of chemicals occur in the environment. Considering that neuroactive chemicals are a group of contaminants that dominate the environment, it is then imperative to understand the combined effects of mixtures. The commonly used models to predict mixture effects, namely concentration addition (CA) and independent action (IA), are thought to be suitable for mixtures of similarly or dissimilarly acting components, respectively. For mixture toxicity prediction, one important challenge is to clarify whether to group neuroactive substances based on similar mechanisms of action, e.g., same molecular target or rather similar toxicological response, e.g., hyper- or hypoactivity (effect direction). We addressed this by using the spontaneous tail coiling (STC) of zebrafish embryos, which represents the earliest observable motor activity in the developing neural network, as a model to elucidate the link between the mechanism of action and toxicological response. Our objective was to answer the following two questions: (1) Can the mixture models CA or IA be used to predict combined effects for neuroactive chemical mixtures when the components share a similar mode of action (i.e., hyper- or hypoactivity) but show different mechanism of action? (2) Will a mixture of chemicals where the components show opposing effect directions result in an antagonistic combined effect? Results indicate that mixture toxicity of chemicals such as propafenone and abamectin as well as chlorpyrifos and hexaconazole that are known to show different mechanisms of action but similar effect directions were predictable using CA and IA models. This could be interpreted with the convergence of effects on the neural level leading to either a collective activation or inhibition of synapses. We also found antagonistic effects for mixtures containing substances with opposing effect direction. Finally, we discuss how the STC may be used to amend risk assessment. Full article

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

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21 pages, 5999 KiB

Open AccessArticle

Bioengineered Matricaria recutita Extract-Assisted Palladium Nanoparticles for the Congo Red Dye Degradation and Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol

by Maqsood Ahmad Malik, Abdulmohsen Ali Alshehri, May Abdullah Abomuti, Ekram Y. Danish and Rajan Patel

Toxics 2021, 9(5), 103; https://doi.org/10.3390/toxics9050103 - 4 May 2021

Cited by 31 | Viewed by 3722

Abstract

The green chemistry method is the preferred approach for synthesizing metal and metal oxide nanoparticles because of its low toxicity, environmental friendliness, feasibility, and safety to human health compared with other chemical or physical methods. The present work reports the phytogenic synthesis of [...] Read more.

The green chemistry method is the preferred approach for synthesizing metal and metal oxide nanoparticles because of its low toxicity, environmental friendliness, feasibility, and safety to human health compared with other chemical or physical methods. The present work reports the phytogenic synthesis of palladium nanoparticles (PdNPs) using an aqueous extract of Matricaria recutita (Chamomile). The phytochemical-mediated synthesis of PdNPs is an economical and eco-friendly approach without using toxic elements as reducing and capping or stabilizing agents. The UV-visible spectroscopic characterization was initially used to confirm the preparation of PdNPs using an aqueous extract of M. recutita flowers as a bioreductant for the reduction of Pd²⁺ to Pd⁰ without using any extra capping and reducing agents. The appearance of surface plasmon resonance (SPR) peak at 286 nm confirmed the formation of M. recutita extract-based PdNPs. Furthermore, the PdNPs were characterized by TEM, SEM, EDX, XRD, XPS, and FTIR to confirm their proper synthesis. The thermogravimetric analysis (TGA) was implemented to interpret the decomposition pattern and thermal stability of as-synthesized PdNPs. The biosynthesized PdNPs were further applied as a nanocatalyst in degradation of an azo dye Congo red (CR) in the presence of NaBH₄. The catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was also investigated in the presence of NaBH₄. All the catalytic reactions were performed in water, and no significant loss in catalytic activity was observed after recovery and reusability of the biosynthesized PdNPs. Full article

(This article belongs to the Special Issue Advanced Research on the Removal of Pollutants by Nanomaterials)

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17 pages, 3290 KiB

Open AccessArticle

Phytochemical and Safety Evaluations of Zingiber ottensii Valeton Essential Oil in Zebrafish Embryos and Rats

by Wisit Thitinarongwate, Raktham Mektrirat, Wutigri Nimlamool, Parirat Khonsung, Surachai Pikulkaew, Siriporn Okonogi and Puongtip Kunanusorn

Toxics 2021, 9(5), 102; https://doi.org/10.3390/toxics9050102 - 3 May 2021

Cited by 13 | Viewed by 4031

Abstract

Zingiber ottensii Valeton (ZO) exhibits pharmacological activity and has long been used in traditional medicine. However, reports about its safety profiles are limited. The present study aimed to evaluate the phytochemical profile and the toxic effects of ZO essential oil on the development [...] Read more.

Zingiber ottensii Valeton (ZO) exhibits pharmacological activity and has long been used in traditional medicine. However, reports about its safety profiles are limited. The present study aimed to evaluate the phytochemical profile and the toxic effects of ZO essential oil on the development of zebrafish and acute oral toxicity in rats. The essential oil was isolated from ZO rhizomes, and phytochemicals were analyzed using a gas chromatography–mass spectrometer (GC–MS). The embryotoxic and teratogenic effects of ZO essential oil were evaluated in zebrafish embryos and larvae and the acute oral toxicity was determined in rats. GC–MS results showed the essential oil contained zerumbone as a major phytoconstituent (24.73%). The zebrafish embryotoxicity of ZO essential oil appeared to be concentration- and time-dependent manner, with a moderate LC₅₀ (1.003 µg/mL). Teratogenicity in zebrafish embryos also included morphological defects, decreased hatchability, and reduced heart rate. In rats, ZO essential oil (2000 mg/kg, p.o.) resulted in no mortality or significant toxicities. These findings suggest that ZO has embryotoxic and teratogenic effects in zebrafish embryos but does not result in death or acute oral toxicity in rats. Further long-term toxicity studies are needed to confirm the safety of products developed from ZO essential oil. Full article

(This article belongs to the Special Issue Current Research on the Cytotoxicity of Drugs to Humans and Animals)

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17 pages, 2391 KiB

Open AccessFeature PaperArticle

Validation of a Method Scope Extension for the Analysis of POPs in Soil and Verification in Organic and Conventional Farms of the Canary Islands

by Andrea Acosta-Dacal, Cristian Rial-Berriel, Ricardo Díaz-Díaz, María del Mar Bernal-Suárez, Manuel Zumbado, Luis Alberto Henríquez-Hernández, Pablo Alonso-González, Eva Parga-Dans and Octavio P. Luzardo

Toxics 2021, 9(5), 101; https://doi.org/10.3390/toxics9050101 - 2 May 2021

Cited by 11 | Viewed by 4346

Abstract

Persistent organic pollutants (POPs) are among the most relevant and dangerous contaminants in soil, from where they can be transferred to crops. Additionally, livestock animals may inadvertently consume relatively high amounts of soil attached to the roots of the vegetables while grazing, leading [...] Read more.

Persistent organic pollutants (POPs) are among the most relevant and dangerous contaminants in soil, from where they can be transferred to crops. Additionally, livestock animals may inadvertently consume relatively high amounts of soil attached to the roots of the vegetables while grazing, leading to indirect exposure to humans. Therefore, periodic monitoring of soils is crucial; thus, simple, robust, and powerful methods are needed. In this study, we have tested and validated an easy QuEChERS-based method for the extraction of 49 POPs (8 PBDEs, 12 OCPs, 11 PAHs, and 18 PCBs) in soils and their analysis by GC-MS/MS. The method was validated in terms of linearity, precision, and accuracy, and a matrix effect study was performed. The limits of detection (LOD) were established between 0.048 and 3.125 ng g⁻¹ and the limits of quantification (LOQ) were between 0.5 and 20 ng g⁻¹, except for naphthalene (50 ng g⁻¹). Then, to verify the applicability of the validated method, we applied it to a series of 81 soil samples from farms dedicated to mixed vegetable cultivation and vineyards in the Canary Islands, both from two modes of production (organic vs. conventional) where residues of OCPs, PCBs, and PAHs were found. Full article

(This article belongs to the Special Issue Environmental and Biological Monitoring: Analytical Methods and Assessment)

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14 pages, 917 KiB

Open AccessFeature PaperArticle

Immunotoxicity of Per- and Polyfluoroalkyl Substances: Insights into Short-Chain PFAS Exposure

by Tracey Woodlief, Samuel Vance, Qing Hu and Jamie DeWitt

Toxics 2021, 9(5), 100; https://doi.org/10.3390/toxics9050100 - 1 May 2021

Cited by 29 | Viewed by 6760 | Correction

Abstract

Novel per- and polyfluoroalkyl substances (PFAS) were recently identified in drinking water sources throughout North Carolina. These include the perfluoroether acids (PFEAs) perfluoro-2-methoxyacetic acid (PFMOAA), perfluoro-2-methoxypropanoic acid (PFMOPrA), and perfluoro-4-methoxybutanioc acid (PFMOBA). Little toxicological data exist for these PFEAs. Therefore, the present study [...] Read more.

Novel per- and polyfluoroalkyl substances (PFAS) were recently identified in drinking water sources throughout North Carolina. These include the perfluoroether acids (PFEAs) perfluoro-2-methoxyacetic acid (PFMOAA), perfluoro-2-methoxypropanoic acid (PFMOPrA), and perfluoro-4-methoxybutanioc acid (PFMOBA). Little toxicological data exist for these PFEAs. Therefore, the present study described signs of toxicity and immunotoxicity following oral exposure. Adult male and female C57BL/6 mice were exposed once/day for 30 days to PFMOAA (0, 0.00025, 0.025, or 2.5 mg/kg), PFMOPrA, or PFMOBA (0, 0.5, 5, or 50 mg/kg). A dose of 7.5 mg/kg of perfluorooctanoic acid (PFOA) was used as a positive control. Terminal body weights, and absolute liver, spleen, or thymus weights did not differ by dose for any compound; exposure to 50 mg/kg of PFMOBA increased relative liver weights in males. Changes in splenic cellularity were observed in males exposed to PFMOPrA and decreased numbers of B and natural killer (NK) cells were observed in males and females exposed to PFMOBA. Exposure did not alter NK cell cytotoxicity or T cell-dependent antibody responses at doses administered. Our results indicate that these “understudied” PFAS have toxicological potential but require additional investigation across endpoints and species, including humans, to understand health effects via drinking water exposure. Full article

(This article belongs to the Special Issue Biological Fate and Potential Hazards of Per- and Polyfluorinated Alkyl Substances (PFAS))

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14 pages, 287 KiB

Open AccessArticle

Organophosphate Pesticide Exposures in Early and Late Pregnancy Influence Different Aspects of Infant Developmental Performance

by Boonsita Suwannakul, Ratana Sapbamrer, Natrujee Wiwattanadittakul and Surat Hongsibsong

Toxics 2021, 9(5), 99; https://doi.org/10.3390/toxics9050099 - 30 Apr 2021

Cited by 13 | Viewed by 2816

Abstract

Organophosphate (OP) pesticides can transfer from mother to fetus via the placenta and amniotic fluid and may affect the development of infants. This study aims to evaluate the associations between maternal OP concentrations collected in the 1st–2nd trimester and the 3rd trimester of [...] Read more.

Organophosphate (OP) pesticides can transfer from mother to fetus via the placenta and amniotic fluid and may affect the development of infants. This study aims to evaluate the associations between maternal OP concentrations collected in the 1st–2nd trimester and the 3rd trimester of pregnancy and the infant developmental performance. The Screening Test of the Bayley Scales of Infants and Toddler Development, Third Edition (BSID–III screening test) was used to assess development performance at 2 and 6 months of age. Multiple regression analysis showed a negative correlation between cognitive performance at 2 months and maternal diethylthiophosphate (DETP) levels in the 1st–2nd trimester (β ± SE = −0.012 ± 0.004, p < 0.05). We also found that expressive communication and fine motor performance at 6 months were negatively associated with maternal diethyldithiophosphate (DEDTP) levels in the 3rd trimester (β ± SE = −0.047 ± 0.016, p < 0.05, and β ± SE = −0.044 ± 0.017, p < 0.05, respectively). These results suggest that maternal ethylated OP concentrations at different timing of exposure during pregnancy may influence different aspects of infant developmental performance. Full article

(This article belongs to the Special Issue Prenatal Exposures and Children’s Health)

19 pages, 1778 KiB

Open AccessFeature PaperReview

The Role of Protein Adduction in Toxic Neuropathies of Exogenous and Endogenous Origin

by Peter S. Spencer and Xiao Chen

Toxics 2021, 9(5), 98; https://doi.org/10.3390/toxics9050098 - 29 Apr 2021

Cited by 7 | Viewed by 2650

Abstract

The peripheral (axonal) neuropathy associated with repeated exposure to aliphatic and aromatic solvents that form protein-reactive γ-diketones shares some clinical and neuropathological features with certain metabolic neuropathies, including type-II diabetic neuropathy and uremic neuropathy, and with the largely sub-clinical nerve damage associated with [...] Read more.

The peripheral (axonal) neuropathy associated with repeated exposure to aliphatic and aromatic solvents that form protein-reactive γ-diketones shares some clinical and neuropathological features with certain metabolic neuropathies, including type-II diabetic neuropathy and uremic neuropathy, and with the largely sub-clinical nerve damage associated with old age. These conditions may be linked by metabolites that adduct and cross-link neuroproteins required for the maintenance of axonal transport and nerve fiber integrity in the peripheral and central nervous system. Full article

(This article belongs to the Special Issue Toxic Neuropathy: Mechanisms, Causes, Risk Exposure, Diagnosis, Prevention and Therapeutic Options)

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19 pages, 2303 KiB

Open AccessFeature PaperArticle

In Silico Exploration of the Potential Role of Acetaminophen and Pesticides in the Etiology of Autism Spectrum Disorder

by Tristan Furnary, Rolando Garcia-Milian, Zeyan Liew, Shannon Whirledge and Vasilis Vasiliou

Toxics 2021, 9(5), 97; https://doi.org/10.3390/toxics9050097 - 27 Apr 2021

Viewed by 4196

Abstract

Recent epidemiological studies suggest that prenatal exposure to acetaminophen (APAP) is associated with increased risk of Autism Spectrum Disorder (ASD), a neurodevelopmental disorder affecting 1 in 59 children in the US. Maternal and prenatal exposure to pesticides from food and environmental sources have [...] Read more.

Recent epidemiological studies suggest that prenatal exposure to acetaminophen (APAP) is associated with increased risk of Autism Spectrum Disorder (ASD), a neurodevelopmental disorder affecting 1 in 59 children in the US. Maternal and prenatal exposure to pesticides from food and environmental sources have also been implicated to affect fetal neurodevelopment. However, the underlying mechanisms for ASD are so far unknown, likely with complex and multifactorial etiology. The aim of this study was to explore the potential effects of APAP and pesticide exposure on development with regards to the etiology of ASD by highlighting common genes and biological pathways. Genes associated with APAP, pesticides, and ASD through human research were retrieved from molecular and biomedical literature databases. The interaction network of overlapping genetic associations was subjected to network topology analysis and functional annotation of the resulting clusters. These genes were over-represented in pathways and biological processes (FDR p < 0.05) related to apoptosis, metabolism of reactive oxygen species (ROS), and carbohydrate metabolism. Since these three biological processes are frequently implicated in ASD, our findings support the hypothesis that cell death processes and specific metabolic pathways, both of which appear to be targeted by APAP and pesticide exposure, may be involved in the etiology of ASD. This novel exposures-gene-disease database mining might inspire future work on understanding the biological underpinnings of various ASD risk factors. Full article

(This article belongs to the Special Issue Prenatal Environmental Exposure and Autism Risk)

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24 pages, 7785 KiB

Open AccessArticle

Cellular Uptake and Toxicological Effects of Differently Sized Zinc Oxide Nanoparticles in Intestinal Cells

by Anna Mittag, Christian Hoera, Alexander Kämpfe, Martin Westermann, Jochen Kuckelkorn, Thomas Schneider and Michael Glei

Toxics 2021, 9(5), 96; https://doi.org/10.3390/toxics9050096 - 27 Apr 2021

Cited by 29 | Viewed by 3373

Abstract

Due to their beneficial properties, the use of zinc oxide nanoparticles (ZnO NP) is constantly increasing, especially in consumer-related areas, such as food packaging and food additives, which is leading to an increased oral uptake of ZnO NP. Consequently, the aim of our [...] Read more.

Due to their beneficial properties, the use of zinc oxide nanoparticles (ZnO NP) is constantly increasing, especially in consumer-related areas, such as food packaging and food additives, which is leading to an increased oral uptake of ZnO NP. Consequently, the aim of our study was to investigate the cellular uptake of two differently sized ZnO NP (<50 nm and <100 nm; 12–1229 µmol/L) using two human intestinal cell lines (Caco-2 and LT97) and to examine the possible resulting toxic effects. ZnO NP (<50 nm and <100 nm) were internalized by both cell lines and led to intracellular changes. Both ZnO NP caused time- and dose-dependent cytotoxic effects, especially at concentrations of 614 µmol/L and 1229 µmol/L, which was associated with an increased rate of apoptotic and dead cells. ZnO NP < 100 nm altered the cell cycle of LT97 cells but not that of Caco-2 cells. ZnO NP < 50 nm led to the formation of micronuclei in LT97 cells. The Ames test revealed no mutagenicity for both ZnO NP. Our results indicate the potential toxicity of ZnO NP after oral exposure, which should be considered before application. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

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17 pages, 1878 KiB

Open AccessArticle

Assessment of Metals Concentrations in Soils of Abu Dhabi Emirate Using Pollution Indices and Multivariate Statistics

by Yousef Nazzal, Alina Bărbulescu, Fares Howari, Ahmed A. Al-Taani, Jibran Iqbal, Cijo M. Xavier, Manish Sharma and Cristian Ștefan Dumitriu

Toxics 2021, 9(5), 95; https://doi.org/10.3390/toxics9050095 - 25 Apr 2021

Cited by 33 | Viewed by 4041

Abstract

The aim of this study was twofold. Firstly, we performed a land capability class determination of the agricultural soils from the Abu Dhabi Emirate, the United Arab Emirates, based on the concentrations of 17 chemical elements determined in the soil samples collected from [...] Read more.

The aim of this study was twofold. Firstly, we performed a land capability class determination of the agricultural soils from the Abu Dhabi Emirate, the United Arab Emirates, based on the concentrations of 17 chemical elements determined in the soil samples collected from 84 locations. Secondly, we assess the soil pollution with different metals, using several pollution indices. The results of Principal Component Analysis (PCA) shows that four principal components (PCs) are responsible for describing the total metals concentrations’ variance, the highest contribution on PC1 being that of Mn, and Cr, on PC2 that of Fe, on PC3 that of Cu, and on PC4 that of Al. After determining the optimal number of clusters, we classified the sites into three clusters, while the studied metals were grouped function on their concentrations. Then, we used five indices to assess the pollution level of the soil at the study sites and in the clusters. The geo—accumulation index (I_geo) indicates uncontamination/moderately contamination with Cu in cluster 1, uncontaminated/moderately contaminate soils with Cd, Cu, and Ni in cluster 2, and uncontaminated/moderately contaminated soil with Cu and moderately contaminated with Pb, Zn, and Ni in cluster 3. By comparison, the enrichment factors overestimate the pollution of the studied sites. The pollution load index (PLI) indicates a baseline level of pollution at 14 sites and the deterioration of the soil quality at four sites. The Nemerow pollution index provides similar results as PLI. Full article

(This article belongs to the Special Issue Statistical Assessment, Modeling, and Mitigation of Water and Soil Pollution)

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12 pages, 1311 KiB

Open AccessArticle

Zinc, Zinc Transporters, and Cadmium Cytotoxicity in a Cell Culture Model of Human Urothelium

by Soisungwan Satarug, Scott H. Garrett, Seema Somji, Mary Ann Sens and Donald A. Sens

Toxics 2021, 9(5), 94; https://doi.org/10.3390/toxics9050094 - 24 Apr 2021

Cited by 11 | Viewed by 3007

Abstract

We explored the potential role of zinc (Zn) and zinc transporters in protection against cytotoxicity of cadmium (Cd) in a cell culture model of human urothelium, named UROtsa. We used real-time qRT-PCR to quantify transcript levels of 19 Zn transporters of the Zrt-/Irt-like [...] Read more.

We explored the potential role of zinc (Zn) and zinc transporters in protection against cytotoxicity of cadmium (Cd) in a cell culture model of human urothelium, named UROtsa. We used real-time qRT-PCR to quantify transcript levels of 19 Zn transporters of the Zrt-/Irt-like protein (ZIP) and ZnT gene families that were expressed in UROtsa cells and were altered by Cd exposure. Cd as low as 0.1 µM induced expression of ZnT1, known to mediate efflux of Zn and Cd. Loss of cell viability by 57% was seen 24 h after exposure to 2.5 µM Cd. Exposure to 2.5 µM Cd together with 10–50 µM Zn prevented loss of cell viability by 66%. Pretreatment of the UROtsa cells with an inhibitor of glutathione biosynthesis (buthionine sulfoximine) diminished ZnT1 induction by Cd with a resultant increase in sensitivity to Cd cytotoxicity. Conversely, pretreatment of UROtsa cells with an inhibitor of DNA methylation, 5-aza-2’-deoxycytidine (aza-dC) did not change the extent of ZnT1 induction by Cd. The induced expression of ZnT1 that remained impervious in cells treated with aza-dC coincided with resistance to Cd cytotoxicity. Therefore, expression of ZnT1 efflux transporter and Cd toxicity in UROtsa cells could be modulated, in part, by DNA methylation and glutathione biosynthesis. Induced expression of ZnT1 may be a viable mechanistic approach to mitigating cytotoxicity of Cd. Full article

(This article belongs to the Special Issue Adverse Health Effects of Persistent Environmental Toxicants)

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20 pages, 3311 KiB

Open AccessArticle

Total and Metabolically Active Microbial Community of Aerobic Granular Sludge Systems Operated in Sequential Batch Reactors: Effect of Pharmaceutical Compounds

by Barbara Muñoz-Palazon, Aurora Rosa-Masegosa, Miguel Hurtado-Martinez, Alejandro Rodriguez-Sanchez, Alexander Link, Ramiro Vilchez-Vargas, Alejandro Gonzalez-Martinez and Jesus Gonzalez Lopez

Toxics 2021, 9(5), 93; https://doi.org/10.3390/toxics9050093 - 23 Apr 2021

Cited by 12 | Viewed by 2770

Abstract

Two aerobic granular sludge (AGS) sequential batch reactors were operated at a mild (15 °C) temperature for 180 days. One of those bioreactors was exposed to a mixture of diclofenac, naproxen, trimethoprim, and carbamazepine. The AGS system, operating under pressure from emerging contaminants, [...] Read more.

Two aerobic granular sludge (AGS) sequential batch reactors were operated at a mild (15 °C) temperature for 180 days. One of those bioreactors was exposed to a mixture of diclofenac, naproxen, trimethoprim, and carbamazepine. The AGS system, operating under pressure from emerging contaminants, showed a decrease in COD, BOD₅, and TN removal capacity, mainly observed during the first 100 days, in comparison with the removal ratios detected in the control bioreactor. After an acclimatisation period, the removal reached high-quality effluent for COD and TN, close to 95% and 90%, respectively. In the steady-state period, trimethoprim and diclofenac were successfully removed with values around 50%, while carbamazepine and naproxen were more recalcitrant. The dominant bacterial OTUs were affected by the presence of a mixture of pharmaceutical compounds, under which the dominant phylotypes changed to OTUs classified among the Pseudomonas, Gemmobacter, and Comamonadaceae. The RT-qPCR and qPCR results showed the deep effects of pharmaceutical compounds on the number of copies of target genes. Statistical analyses allowed for linking the total and active microbial communities with the physico-chemical performance, describing the effects of pharmaceutical compounds in pollution degradation, as well as the successful adaptation of the system to treat wastewater in the presence of toxic compounds. Full article

(This article belongs to the Special Issue Advanced Technologies to Remove Toxic Compounds in Wastewater)

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16 pages, 2391 KiB

Open AccessArticle

Cytotoxicity and Microbicidal Activity of Commonly Used Organic Solvents: A Comparative Study and Application to a Standardized Extract from Vaccinium macrocarpon

by Yana Ilieva, Lyudmila Dimitrova, Maya Margaritova Zaharieva, Mila Kaleva, Petko Alov, Ivanka Tsakovska, Tania Pencheva, Ivanka Pencheva-El Tibi, Hristo Najdenski and Ilza Pajeva

Toxics 2021, 9(5), 92; https://doi.org/10.3390/toxics9050092 - 21 Apr 2021

Cited by 26 | Viewed by 3990

Abstract

The cytotoxicity and microbicidal capacity of seven organic solvents commonly applied for studying plant extracts and bioactive compounds were systematically investigated based on international standards. Four cell lines of normal (CCL-1, HaCaT) or tumor (A-375, A-431) tissue origin, seven bacterial and one fungal [...] Read more.

The cytotoxicity and microbicidal capacity of seven organic solvents commonly applied for studying plant extracts and bioactive compounds were systematically investigated based on international standards. Four cell lines of normal (CCL-1, HaCaT) or tumor (A-375, A-431) tissue origin, seven bacterial and one fungal strain were used. The impact of the least toxic solvents in the determination of in vitro cytotoxicity was evaluated using a standardized extract from Vaccinium macrocarpon containing 54.2% v/v proanthocyanidins (CystiCran^®). The solvents ethanol, methoxyethanol and polyethylene glycol were the least cytotoxic to all cell lines, with a maximum tolerated concentration (MTC) between 1 and 2% v/v. Ethanol, methanol and polyethylene glycol were mostly suitable for antimicrobial susceptibility testing, with minimum inhibitory concentrations (MICs) ≥ 25% v/v. The MTC values of the solvents dimethyl sulfoxide, dimethoxyethane and dimethylformamide varied from 0.03% to 1.09% v/v. The MICs of dimethyl sulfoxide, methoxyethanol and dimethoxyethane were in the range of 3.125–25% v/v. The cytotoxic effects of CystiCran^® on eukaryotic cell lines were directly proportional to the superimposed effect of the solvents used. The results of this study can be useful for selecting the appropriate solvents for in vitro estimation of the cytotoxic and growth inhibitory effects of bioactive molecules in eukaryotic and prokaryotic cells. Full article

(This article belongs to the Section Toxicology)

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17 pages, 1148 KiB

Open AccessFeature PaperArticle

Co-Cropping Indian Mustard and Silage Maize for Phytoremediation of a Cadmium-Contaminated Acid Paddy Soil Amended with Peat

by Sifan Wang, Yong Liu, Khalil Kariman, Jialin Li, Huihua Zhang, Fangbai Li, Yinglong Chen, Chongjian Ma, Chuanping Liu, Yuzhen Yuan, Zhiqiang Zhu and Zed Rengel

Toxics 2021, 9(5), 91; https://doi.org/10.3390/toxics9050091 - 21 Apr 2021

Cited by 9 | Viewed by 3079

Abstract

Co-cropping is an eco-friendly strategy to improve the phytoremediation capacity of plants growing in soils contaminated with heavy metals such as cadmium (Cd). This study was conducted to investigate the effects of co-cropping Indian mustard (Brassicajuncea) and silage maize ( [...] Read more.

Co-cropping is an eco-friendly strategy to improve the phytoremediation capacity of plants growing in soils contaminated with heavy metals such as cadmium (Cd). This study was conducted to investigate the effects of co-cropping Indian mustard (Brassicajuncea) and silage maize (Zeamays) and applying peat on the phytoremediation of a Cd-contaminated acid paddy soil via characterizing plant growth and Cd uptake in pot experiments. There were six planting patterns (Control: no plants; MI-2 and MI-4: mono-cropping of Indian mustard at low and high densities, respectively; MS: mono-cropping of silage maize; CIS-2 and CIS-4: co-cropping of Indian mustard at low and high densities with silage maize, respectively) and two application rates of peat (NP: 0; WP: 30 g kg⁻¹). When Indian mustard and silage maize were co-cropped, the shoot biomass of Indian mustard plants per pot was significantly (p < 0.05) lower than that obtained in the mono-cropping systems, with a substantial reduction (55–72%) in the same plant density group. The shoot biomass of silage maize plants in the mono-cropping systems did not differ significantly from that in the co-cropping systems regardless of the density of Indian mustard. The growth-promoting effect of the peat application was more pronounced in Indian mustard than silage maize. Under the low density of Indian mustard, the co-cropping systems significantly (p < 0.05) decreased Cd uptake by silage maize. Additionally, soil amendment with peat significantly (p < 0.05) increased shoot Cd removal rate and Cd translocation factor value in the co-cropping systems. Taken together, the results demonstrated that silage maize should be co-cropped with Indian mustard at an appropriate density in Cd-polluted soils to achieve simultaneous remediation of Cd-contaminated soils (via Indian mustard) and production of crops (here, silage maize). Peat application was shown to promote the removal of Cd from soil and translocation of Cd into shoots and could contribute to enhanced phytoremediation of Cd-contaminated acid paddy soil. Full article

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

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16 pages, 280 KiB

Open AccessArticle

Phthalate Exposures in the Neonatal Intensive Care Unit

by Randall Jenkins, Devlynne Ondusko, Luke Montrose, Ryan Forbush and David Rozansky

Toxics 2021, 9(5), 90; https://doi.org/10.3390/toxics9050090 - 21 Apr 2021

Cited by 9 | Viewed by 3041

Abstract

Background: Di-2-ethylhexyl phthalate (DEHP), a phthalate compound found in medical devices, may cause toxic effects in premature infants. In this study, the objective is to quantify DEHP exposures from various intravenous and respiratory therapy devices, and to use these values to predict typical [...] Read more.

Background: Di-2-ethylhexyl phthalate (DEHP), a phthalate compound found in medical devices, may cause toxic effects in premature infants. In this study, the objective is to quantify DEHP exposures from various intravenous and respiratory therapy devices, and to use these values to predict typical exposure for an infant in a neonatal unit. Methods: Common IV products used on infants are directed through various types of IV tubing (IVT) and analyzed for DEHP content. DEHP exposure for infants receiving respiratory therapy was determined indirectly through analysis of urine DEHP metabolites. By deriving these values for DEHP we calculated the daily exposure to DEHP from common IV fluids (IVF) and respiratory devices during hospitalization in a neonatal unit. Results: IVF labeled DEHP-positive showed very high concentrations of DEHP, but when passed through IVT, substantial amounts were adsorbed. DEHP was undetectable with all DEHP-negative IVF tests, except when passed through DEHP-positive IVT. The DEHP leached from most respiratory devices was relatively modest, except that detected from bubble CPAP. In 14 very low birthweight infants, the mean DEHP exposure was 182,369 mcg/kg over 81.2 days of the initial hospitalization. Ninety-eight percent of the exposure was from respiratory devices, with bubble CPAP accounting for 95% of the total DEHP exposure in these infants. Conclusions: The DEHP exposure in our neonatal unit can be reduced markedly by avoiding or modifying bubble CPAP equipment and avoiding IV tubing containing DEHP. Full article

(This article belongs to the Special Issue Phthalate Exposure: From Quantification to Risk Assessment)

10 pages, 8913 KiB

Open AccessArticle

Cumulative Protective Effect of Melatonin and Indole-3-Propionic Acid against KIO₃—Induced Lipid Peroxidation in Porcine Thyroid

by Paulina Iwan, Jan Stepniak and Malgorzata Karbownik-Lewinska

Toxics 2021, 9(5), 89; https://doi.org/10.3390/toxics9050089 - 21 Apr 2021

Cited by 18 | Viewed by 2887

Abstract

Iodine deficiency is the main environmental factor leading to thyroid cancer. At the same time iodine excess may also contribute to thyroid cancer. Potassium iodate (KIO₃), which is broadly used in salt iodization program, may increase oxidative damage to membrane lipids [...] Read more.

Iodine deficiency is the main environmental factor leading to thyroid cancer. At the same time iodine excess may also contribute to thyroid cancer. Potassium iodate (KIO₃), which is broadly used in salt iodization program, may increase oxidative damage to membrane lipids (lipid peroxidation, LPO) under experimental conditions, with the strongest damaging effect at KIO₃ concentration of ~10 mM (corresponding to physiological iodine concentration in the thyroid). Melatonin and indole-3-propionic acid (IPA) are effective antioxidative indoles, each of which protects against KIO₃-induced LPO in the thyroid. The study aims to check if melatonin used together with IPA (in their highest achievable in vitro concentrations) reveals stronger protective effects against KIO₃-induced LPO in porcine thyroid homogenates than each of these antioxidants used separately. Homogenates were incubated in the presence of KIO₃ (200; 100; 50; 25; 20; 15; 10; 7.5; 5.0; 2.5; 1.25; 0.0 mM) without/with melatonin (5 mM) or without/with IPA (10 mM) or without/with melatonin + IPA, and then, to further clarify the narrow range of KIO₃ concentrations, against which melatonin + IPA reveal cumulative protective effects, the following KIO₃ concentrations were used: 20; 18.75; 17.5; 16.25; 15; 13.75; 12.5; 11.25; 10; 8.75; 7.5; 0.0 mM. Malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) concentration (LPO index) was measured spectrophotometrically. Protective effects of melatonin + IPA were stronger than those revealed by each antioxidant used separately, but only when LPO was induced by KIO₃ in concentrations from 18.75 mM to 8.75 mM, corresponding to physiological iodine concentration in the thyroid. In conclusion, melatonin and indole-3-propionic acid exert cumulative protective effects against oxidative damage caused by KIO₃, when this prooxidant is used in concentrations close to physiological iodine concentrations in the thyroid. Therefore, the simultaneous administration of these two indoles should be considered to prevent more effectively oxidative damage (and thereby thyroid cancer formation) caused by iodine compounds applied in iodine prophylaxis. Full article

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

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