Assessment of potential ecological risk for microplastics in freshwater ecosystems.

Microplastics (MPs) are one of the most widespread environmental pollutants, but their risk assessment to freshwater ecosystems has not been clearly investigated. Risk assessment has been constrained by the absence of MP concentration in some environment, the diverse types and shapes of MPs, and limitations of polystyrene (PS)-biased toxicity studies. This study examined exposure to MPs in rivers and lakes worldwide, including China (the Three Gorges Dam & Yangtze River (TGD & YR) and the lakes of Wuhan city (WL)), Vietnam (seven lakes of Da Nang city (7UL)), Europe (the Rhine River (RR)), Finland (Kallavesi Lake (KL)), Argentina (nine lakes in the Patagonia region (9LP)), Brazil (Guaiba Lake (GL)), and South Korea (Nakdong River (NR), Han River (HR), and Anyang Stream (AS)), and assessed the risks to aquatic ecosystems based on the toxicity information and morphology of MPs.

Dechorionated zebrafish embryos improve evaluation of nanotoxicity.

Introduction: In response to the growing need to evaluate nanomaterial (NM) toxicity and compliance with the "3Rs" principles (replacement, reduction, and refinement of animal experiments), zebrafish () embryos have emerged as a promising alternative model for studies on NM toxicity. However, zebrafish embryos are surrounded by an acellular envelope, the chorion, which limits the permeability of NMs. The present study investigated the importance of dechorionated zebrafish embryos for evaluating NM toxicity.

Biodistribution of synthesized polyethylene terephthalate fibers in adult zebrafish, their sex hormone disruption effect, and mitigation using natural organic matter.

Although polyethylene terephthalate (PET) fibers are a representative form of plastic pollutants, studies on their toxicity are currently limited compared to other plastic types. Moreover, the effect of natural organic matter (NOM) on their toxicity has not been investigated. In this study, female and male adult zebrafish were exposed to synthesized PET fibers at concentrations of 0.

Merkel cells and corpuscles of Stannius as putative targets for polyethylene terephthalate microfibers in sheepshead minnow larvae.

Polyethylene terephthalate (PET) fibers are contaminated in wastewater from various primary sources, such as washing textile waters. PET fibers in the environment can be degraded into microfibers because of weathering processes such as sunlight, physical wear, and heat. Although recent studies reported adverse effects of PET microfibers on aquatic organisms, the lack of information on their toxicity and mode of action hampers the risk assessment of PET microfibers.

Co-exposure to microplastic and plastic additives causes development impairment in zebrafish embryos.

Since the run off of microplastic and plastic additives into the aquatic environment through the disposal of plastic products, we investigated the adverse effects of co-exposure to microplastics and plastic additives on zebrafish embryonic development. To elucidate the combined effects between microplastic mixtures composed of microplastics and plastic additives in zebrafish embryonic development, polystyrene (PS), bisphenol S (BPS), and mono-(2-ethylhexyl) phthalate (MEHP) were chosen as a target contaminant. Based on non-toxic concentration of each contaminant in zebrafish embryos, microplastic mixtures which is consisted of binary and ternary mixed forms were prepared.

Ultra-high performance concrete alleviates ecotoxicological effects in aquatic organisms.

With the advancement of cementitious material technologies, ultra-high performance concretes incorporating nano- and(or) micro-sized particle materials have been developed; however, their environmental risks are still poorly understood. This study investigates the ecotoxicological effects of ultra-high performance concrete (UC) leachate by comparing with that of the conventional concrete (CC) leachate. For this purpose, a dynamic leaching test and a battery test with algae, water flea, and zebrafish were performed using standardized protocols.

Comparison of gut toxicity and microbiome effects in zebrafish exposed to polypropylene microplastics: Interesting effects of UV-weathering on microbiome.

Weathered microplastics (MPs) exhibit different physicochemical properties compared to pristine MPs, thus, their effects on the environment and living organisms may also differ. In the present study, we investigated the gut-toxic effects of virgin polypropylene MPs (PP) and UV-weathered PP MPs (UV-PP) on zebrafish. The zebrafish were exposed to the two types of PP MPs at a concentration of 50 mg/L each for 14 days.

Elucidating adsorption mechanisms of benzalkonium chlorides (BACs) on polypropylene and polyethylene terephthalate microplastics (MPs): Effects of BACs alkyl chain length and MPs characteristics.

Since the onset of the COVID-19 pandemic, there has been an increase in the use of disposable plastics and disinfectants. This study systematically investigated the adsorption behavior and mechanisms of benzalkonium chlorides (BACs), commonly used disinfectants, on polypropylene (PP) and polyethylene terephthalate (PET) microplastics (MPs), considering various factors, such as characteristics of MPs, alkyl chain length of BACs, and environmental conditions. Our results demonstrated a higher adsorption capacity for PP-MPs with relatively hydrophobic properties compared to PET-MPs, where longer alkyl chains in BACs (i.

Characterization of novel HLA-A*24:608N allele discovered in Koreans.

A novel null HLA-A*24 allele, HLA-A*24:608N, was identified in five Korean subjects including three from a family and two separate individuals. This study was performed to discern its immunological function in transplantation settings. Because this null variant had deletions of approximately 12 k base pairs from intron 3 to 3' end of the HLA-A gene, low resolution HLA typing and amplicon-based next generation sequencing (NGS) typing methods had failed to assign it.

Thyroid-gonadal hormonal interplay in zebrafish exposed to sodium perchlorate: Implications for reproductive health.

Perchlorate, a widespread environmental contaminant originating from various industrial applications, agricultural practices, and natural sources, poses potential risks to ecosystems and human health. While previous studies have highlighted its influence on the thyroid endocrine system and its impact on gonadal maturation, reproduction, and sex hormone synthesis, the specific interplay between thyroid and steroid hormones, in this context, remains largely unexplored. Therefore, this study was undertaken to investigate the adverse effects and underlying mechanisms triggered by exposure to sodium perchlorate (SP) on reproductive endocrine activity in zebrafish.

Modified toxic potential of multi-walled carbon nanotubes to zebrafish (Danio rerio) following a two-year incubation in water.

Multi-walled carbon nanotubes (MWCNTs), widely used in several industrial fields, are not readily degradable thus, persist in environmental matrices, serving as a source of environmental toxicity to organisms. However, the effects of environmental weathering on nanomaterial toxicity remain unclear. Herein, we prepared aged-MWCNTs (a-CNTs) by incubating commercial pristine-MWCNTs (p-CNTs) for two years and compared their changes in physicochemical properties and toxic effects on zebrafish.

Reproductive disorders linked to the interaction between sex steroid and thyroid hormonal activities, oxidative stress responses, and the rate of metabolism of tris (1,3-dichloro-2-propyl) phosphate (TDCPP) in zebrafish.

The objective of this study was to assess the thyroid hormone disruption and reproductive dysfunction effects of the bioaccumulation and rate of mechanism in zebrafish exposed to tris(1,3-dichloro-2-propyl) phosphate (TDCPP), with stress responsiveness. The fish were exposed to test concentrations of TDCPP (0, 0.06, 0.

Identification of aquatic ecological risk of bisphenol S in four Asian countries based on the SSD and alternative toxicity data of model species Danio rerio.

Bisphenol S (BPS), an organic compound and bisphenol analog, is commonly used as a substitute for bisphenol A. BPS is widely used in epoxy glues, can coatings, and thermal receipt papers; however, its risks have not been fully determined and the probability of its toxicity has been continuously suggested. In this study, we conducted BPS toxicity tests on aquatic plants (acute), cladocerans (acute and chronic), and fish (chronic) to determine its adverse effects, and calculated the toxicity values.

Chronic effects of nano and microplastics on reproduction and development of marine copepod Tigriopus japonicus.

This study aimed to examine the impact of chronic (30 days) exposure to polystyrene microplastics (PS-MPs) of different sizes (50 nm and 2 µm) and at different concentrations (0.5 μg/L and 100 mg/L) to marine copepod Tigriopus japonicus. Polystyrene microplastics affected survival rates in size- and concentration-dependent manners.

Biokinetics of fluorophore-conjugated polystyrene microplastics in marine mussels.

Biokinetic information on microplastics in bivalves is required to reduce the human exposure, but little is known about the time-course and size effect on tissue absorption and clearance. The biokinetics of fluorophore-labeled polystyrene microbeads with diameters 10 µm (PL10) and 90 µm (PL90) in Mytilus galloprovincialis marine mussels was investigated in the present study. It was found that both PL10 and PL90 showed a biphasic tissue distribution pattern in digestive and non-digestive tissues, highlighting the significant tissue distribution starting from 48 h post-treatment.

Microplastics released from food containers can suppress lysosomal activity in mouse macrophages.

The ingestion and accumulation of microplastics is a serious threat to the health and survival of humans and other organisms given the increasing use of daily-use plastic products, especially during the COVID-19 pandemic. However, whether direct microplastic contamination from plastic packaging is a threat to human health remains unclear. We analyzed the market demand for plastic packaging in Asia-Pacific, North America, and Europe and identified the commonly used plastic food packaging products.

Long-term exposure of the Mediterranean mussels, Mytilus galloprovincialis to polyethylene terephthalate microfibers: Implication for reproductive and neurotoxic effects.

As one of major types of microplastics (MPs), microfibers (MFs) are widely found in the marine ecosystem and can induce diverse impacts on various marine organisms. Sedentary species, such as mussels, can act as bioindicators for monitoring marine contamination. Hence, in this study, we used mussels (Mytilus galloprovincialis) to examine the toxicity of polyethylene terephthalate (PET) MFs of 100 μm size at concentrations of 0.

A Screening of the MMV Pandemic Response Box Reveals Epetraborole as a New Potent Inhibitor against .

is the one of the most feared bacterial respiratory pathogens in the world. Unfortunately, there are many problems with the current therapies available. These problems include misdiagnoses, high drug resistance, poor long-term treatment outcomes, and high costs.

Impact of polyethylene terephthalate microfiber length on cellular responses in the Mediterranean mussel Mytilus galloprovincialis.

Many studies have investigated the toxic effects of microplastics in marine organisms, but most studied nano-sized round microplastics at high concentrations and were not environmentally relevant. To understand the cellular toxicity of polyethylene terephthalate microfibers (PET-MFs) by length (50 and 100 μm), Mediterranean mussels (Mytilus galloprovincialis) were exposed to environmental (0.5 μg/L) and high (100 mg/L) MF concentrations for four days.

A Novel Approach to Derive the Predicted No-Effect Concentration (PNEC) of Benzophenone-3 (BP-3) Using the Species Sensitivity Distribution (SSD) Method: Suggestion of a New PNEC Value for BP-3.

The necessity for the aquatic ecological risk assessment for benzophenone-3 (BP-3) is increasing due to its high toxic potential and high detection frequency in freshwater. The initial step in the ecological risk assessment is to determine predicted no-effect concentration (PNEC). This study derived PNEC of BP-3 in freshwater using a species sensitivity distribution (SSD) approach, whilst existing PNECs are derived using assessment factor (AF) approaches.

Real-time heart rate monitoring system for cardiotoxicity assessment of Daphnia magna using high-speed digital holographic microscopy.

Machine vision techniques for monitoring heart rates in aquatic bioassays have been applied to cardiotoxicity assessment. However, the requisite large data sizes and long calculation times make long-term observations of heart rates difficult. In this study, we developed a real-time heart rate monitoring system for individual Daphnia magna in a water chamber mounter that immobilizes their movement in 100 mL media.

Silver Ion Release Accelerated in the Gastrovascular Cavity of Hydra vulgaris Increases the Toxicity of Silver Sulfide Nanoparticles.

Silver nanoparticles (Ag-NPs) streamed into aquatic environments are chemically transformed into various forms, and one of the predominant forms is silver sulfide NPs (Ag S-NPs). Because of the lower dissolution rate of silver ions (Ag ), the toxicity of Ag S-NPs could be lower than that of Ag-NPs. However, the toxicity of Ag S-NPs has been observed to be restored under oxidative or acidic conditions.