Azole-Induced Color Vision Deficiency Associated with Thyroid Hormone Signaling: An Integrated In Vivo, In Vitro, and In Silico Study

Bioaccessibility and health risk assessment of hydrophobic organic pollutants in soils from four typical industrial contaminated sites in China

There have been reports of potential health risks for people from hydrophobic organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated hydrocarbons (PCHs), and organophosphate flame retardants (OPFRs). When a contaminated site is used for residential housing or public utility and recreation areas, the soil-bound organic pollutants might pose a threat to human health. In this study, we investigated the contamination profiles and potential risks to human health of 15 PAHs, 6 PCHs, and 12 OPFRs in soils from four contaminated sites in China. We used an in vitro method to determine the oral bioaccessibility of soil pollutants. Total PAHs were found at concentrations ranging from 26.4 ng/g to 987 ng/g. PCHs (0.27‒14.3 ng/g) and OPFRs (6.30‒310 ng/g) were detected, but at low levels compared to earlier reports. The levels of PAHs, PCHs, and OPFRs released from contaminated soils into simulated gastrointestinal fluids ranged from 1.74% to 91.0%, 2.51% to 39.6%, and 1.37% to 96.9%, respectively. Based on both spiked and unspiked samples, we found that the oral bioaccessibility of pollutants was correlated with their logKow and molecular weight, and the total organic carbon content and pH of soils. PAHs in 13 out of 38 contaminated soil samples posed potential high risks to children. When considering oral bioaccessibility, nine soils still posed potential risks, while the risks in the remaining soils became negligible. The contribution of this paper is that it corrects the health risk of soil-bound organic pollutants by detecting bioaccessibility in actual soils from different contaminated sites.

Early-life exposure to five biodegradable plastics impairs eye development and visually-mediated behavior through disturbing hypothalamus-pituitary-thyroid (HPT) axis in zebrafish larvae

Biodegradable plastics have been commonly developed and applied as an alternative to traditional plastics, which cause environmental plastic pollution. However, biodegradable plastics still present limitations such as stringent degradation conditions and slow degradation rate, and may cause harm to the environment and organisms. Consequently, in this study, zebrafish was used to evaluate the effects of five biodegradable microplastics (MPs), polyglycolic acid (PGA), polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA) and polybutylene adipate terephthalate (PBAT) exposure on the early development, retina morphology, visually-mediated behavior, and thyroid signaling at concentrations of 1 mg/L and 100 mg/L. The results indicated that all MPs induced decreased survival rate, reduced body length, smaller eyes, and smaller heads, affecting the early development of zebrafish larvae. Moreover, the thickness of retinal layers, including inner plexiform layer (IPL), outer nuclear layer (ONL), and retinal ganglion layer (RGL) was decreased, and the expression of key genes related to eye and retinal development was abnormally altered after all MPs exposure. Exposure to PBS and PBAT led to abnormal visually-mediated behavior, indicating likely affected the visual function. All MPs could also cause thyroid system disorders, among which alterations in the thyroid hormone receptors (TRs) genes could affect the retinal development of zebrafish larvae. In summary, biodegradable MPs exhibited eye developmental toxicity and likely impaired the visual function in zebrafish larvae. This provided new evidence for revealing the effects of biodegradable plastics on aquatic organism development and environmental risks to aquatic ecosystems.

Long-term exposure to climbazole may affect the health of stress-tolerant coral Galaxea fascicularis

The persistence of coral reefs globally is threatened by various forms of chemical pollution. Climbazole, an azole antibacterial agent extensively utilized in pharmaceuticals and personal care products (PPCPs) in everyday life, has been detected in various environment media and proved to have significant adverse effects on aquatic organism. However, the effects of climbazole on coral remain largely unknown. Therefore, in this study, we conducted a 42-day investigation to examine the effects of varying concentrations of climbazole on Galaxea fascicularis (G. fascicularis), a stress-tolerant coral species. Our investigations included coral color observations, physiological experiments, and assessments of microbial diversity. The results showed that, after 42 days of exposure, the coral color in the treatment group exposed to 100 μg/L climbazole significantly decreased by one color category on the reference chart (D6 shifted to D5), while there was no change in the control group. This was accompanied by an increase in oxidative stress and a decrease in photosynthetic capacity in coral specimens. Additionally, there was a notable alteration in microbial diversity, resulting in reduced community stability. Elevated levels of climbazole (100 μg/L) stress led to an increased abundance of potentially pathogenic bacteria such as unclassified Erysipelotrichaceae. However, at an environmentally relevant concentration of 1 μg/L, climbazole decreased the photosynthetic efficiency and induced oxidative stress in the stress-tolerant coral G. fascicularis, while not significantly impacting the microbial community diversity of the coral. The findings of our study have important implications for the protection and management of nearshore coral reefs and offer essential data for ecological risk assessment of climbazole.

Effects of Insecticide and Herbicides on Thyroid Disturbances in Zebrafish

Thyroid cancer usually begins with thyroid dysfunction and nodules and has become the most common cancer globally, especially in women. Although the causes of thyroid dysfunction are complex, the presence of environmental pollutants, especially certain pesticides as established mutagens, has been widely accepted. Zebrafish (Danio rerio) have similar toxic reactions and signal transduction pathways to humans and are very similar to humans in physiology, development, and metabolic function. Here, the direct toxicity effects and mechanisms of different insecticides and herbicides on zebrafish thyroid functions and indirect toxicity effects originating from thyroid dysfunction were summarized and compared. The overall toxicity of insecticides on the zebrafish thyroid was greater than that of herbicides based on effective concentrations. Penpropathrin and atrazine were more typical thyroid disruptors than other pesticides. Meanwhile, chiral pesticides showed more sophisticated single/combined toxicity effects on both parental and offspring zebrafish. Besides thyroid hormone levels and HPT axis-related gene expression alteration, developmental toxicity, immunotoxicity, and oxidative damage effects were all observed. These data are necessary for understanding the thyroid interference effect of pesticides on humans and for screening for thyroid disruptors in surface water with zebrafish models for the pre-assessment of human health risks and ecological risk control in the future.

A ubiquitous tire rubber additive induced serious eye injury in zebrafish (Danio rerio)

Previous studies have indicated that tire wear particles (TWPs) leachate exposure induced serious eye injury in fish through inhibiting the thyroid peroxidase (TPO) enzyme activity. However, the main TPO inhibitors in the leachate were still unknown. In this study, we identified 2-Mercaptobenzothiazole (MBT) as the potential TPO inhibitor in the TWPs leachate through references search, model prediction based on Danish QSAR and ToxCast database, molecular docking, and in vivo assay. We further explored the toxic mechanism of MBT under environmentally relevant concentrations. The decreased eye size of zebrafish larvae was mainly caused by the decreased lens diameter and cell density in the inner nuclear layer (INL) and outer nuclear layer (ONL) of the retina. Transcriptomics analysis demonstrated that the eye phototransduction function was significantly suppressed by inhibiting the photoreceptor cell proliferation process after MBT exposure. The altered opsin gene expression and decreased opsin protein levels were induced by weakening thyroid hormone signaling after MBT treatment. These results were comparable to those obtained from a known TPO inhibitor, methimazole. This study has identified MBT as the primary TPO inhibitor responsible for inducing eye impairment in zebrafish larvae exposed to TWPs leachate. It is crucial for reducing the toxicity of TWPs leachate in fish.

Prediction of acute toxicity for Chlorella vulgaris caused by tire wear particle-derived compounds using quantitative structure-activity relationship models

Tire wear particles (TWPs) enter aquatic ecosystems through various pathways, such as rainwater and urban runoff. Additives in TWPs can harm aquatic organisms in these ecosystems. Therefore, it is essential to investigate their toxicity to aquatic organisms. In our study, we initially recorded the median effective concentrations of 21 TWP-derived compounds on Chlorella vulgaris growth, ranging from 0.04 to 8.60 mg/L. Subsequently, through an extensive review of the literature, we incorporated 112 compounds with specific toxicity endpoints to construct the QSAR model using genetic algorithm and multiple linear regression techniques, followed by the construction of the consensus model and the quantitative read-across structure-activity relationship (q-RASAR) model. Meanwhile, we employed rigorous internal and external validation measures to assess the performance of the model. The results indicated that the developed q-RASAR model exhibited strong adaptation, robustness, and reliable prediction, with q-RASAR indicators of Q2LOO = 0.7673, R2tr = 0.8079, R2test = 0.8610, Q2Fn = 0.8285-0.8614, and CCCtest = 0.9222. Based on an external dataset containing 128 emerging TWP-derived compounds, the model's applicability domain coverage was 90.6 %. The q-RASAR model predicted that the structure of diphenylamine was associated with higher toxicity, possibly liked to the SpMax2_Bhm and LogBCF descriptors. The established model reliably provides prediction and fills a critical data gap. These findings highlight the potential risks posed by emerging TWP-derived compounds to aquatic organisms.

The azole biocide climbazole induces oxidative stress, inflammation, and apoptosis in fish gut

Climbazole is an azole biocide that has been widely used in formulations of personal care products. Climbazole can cause developmental toxicity and endocrine disruption as well as gut disturbance in aquatic organisms. However, the mechanisms behind gut toxicity induced by climbazole still remain largely unclear in fish. Here, we evaluate the gut effects by exposing grass carp (Ctenopharyngodon idella) to climbazole at levels ranging from 0.2 to 20 μg/L for 42 days by evaluating gene transcription and expression, biochemical analyses, correlation network analysis, and molecular docking. Results showed that climbazole exposure increased cyp1a mRNA expression and ROS level in the three treatment groups. Climbazole also inhibited Nrf2 and Keap1 transcripts as well as proteins, and suppressed the transcript levels of their subordinate antioxidant molecules (cat, sod, and ho-1), increasing oxidative stress. Additionally, climbazole enhanced NF-κB and iκBα transcripts and proteins, and the transcripts of NF-κB downstream pro-inflammatory factors (tnfα, and il-1β/6/8), leading to inflammation. Climbazole increased pro-apoptosis-related genes (fadd, bad1, and caspase3), and decreased anti-apoptosis-associated genes (bcl2, and bcl-xl), suggesting a direct reaction to apoptosis. The molecular docking data showed that climbazole could form stable hydrogen bonds with CYP1A. Mechanistically, our findings suggested that climbazole can induce inflammation and oxidative stress through CYP450s/ROS/Nrf2/NF-κB pathways, resulting in cell apoptosis in the gut of grass carp.

A fast method for the determination of personal care product chemicals in human urine using dispersive liquid-liquid extraction and ultra high-performance liquid chromatography-tandem mass spectrometry

RATIONALE

Personal care product chemicals (PCPCs) are the chemicals used in personal care products. Many of them are endocrine disruptors and have potential adverse effects on humans. The concentrations of PCPCs in urine are the main biomarker for assessing human exposure.

METHODS

A method was developed for the simultaneous determination of 14 PCPCs in human urine using dispersive liquid-liquid extraction combined with ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).

RESULTS

Compared with liquid-liquid extraction, this method had the advantages of time efficiency, sensitivity, and limited organic solvent consumption. It produced good linearity (0.9965-0.9996), limits of detection (2.82-36.36 pg mL-1 ), limits of quantitation (9.39-121.08 pg mL-1 ), matrix effect (-0.90%-2.55%), intra-day precision (relative standard deviations [RSDs] <15%), and inter-day precision (RSDs <19.9%). The method had satisfactory relative recovery at three concentration levels.

CONCLUSIONS

A rapid method was developed for the simultaneous quantification of 14 PCPCs in human urine. The practicability of the method was verified with 21 urine from university students. It is expected that this method will provide a powerful reference for the assessment of exposure to PCPCs in large populations.

Neurological impairment is crucial for tire rubber-derived contaminant 6PPDQ-induced acute toxicity to rainbow trout

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPDQ) has attracted significant attention due to its highly acute lethality to sensitive salmonids. However, studies investigating the mechanisms underlying its acute toxicity have been lacking. In this work, we demonstrated the sensitivity of rainbow trout to 6PPDQ-induced mortality. Moribund trout exhibited significantly higher brain concentrations of 6PPDQ compared to surviving trout. In an in vitro model using human brain microvascular endothelial cells, 6PPDQ can penetrate the blood-brain barrier and enhance blood-brain barrier permeability without compromising cell viability. The time spent in the top of the tank increased with rising 6PPDQ concentrations, as indicated by locomotion behavior tests. Furthermore, 6PPDQ influenced neurotransmitter levels and mRNA expression of neurotransmission-related genes in the brain and exhibited strong binding affinity to target neurotransmission-related proteins using computational simulations. The integrated biomarker response value associated with neurotoxicity showed a positive linear correlation with trout mortality. These findings significantly contribute to filling the knowledge gap between neurological impairments and apical outcomes, including behavioral effects and mortality, induced by 6PPDQ.

An azole fungicide climbazole damages the gut-brain axis in the grass carp

Azole antifungal climbazole has frequently been detected in aquatic environments and shows various effects in fish. However, the underlying mechanism of toxicity through the gut-brain axis of climbazole is unclear. Here, we investigated the effects of climbazole at environmental concentrations on the microbiota-intestine-brain axis in grass carp via histopathological observation, gene expression and biochemical analyses, and high-throughput sequencing of the 16 S rRNA. Results showed that exposure to 0.2 to 20 μg/L climbazole for 42 days significantly disrupted gut microbiota and caused brain neurotoxicity in grass carp. In this study, there was an alteration in the phylum and genus compositions in the gut microbiota following climbazole treatment, including reducing Fusobacteria (e.g., Cetobacterium) and increasing Actinobacteria (e.g., Nocardia). Climbazole disrupted intestinal microbial abundance, leading to increased levels of lipopolysaccharide and tumor necrosis factor-alpha in the gut, serum, and brain. They passed through the impaired intestinal barrier into the circulation and caused the destruction of the blood-brain barrier through the gut-brain axis, allowing them into the brain. In the brain, climbazole activated the nuclear factor kappaB pathway to increase inflammation, and suppressed the E2-related factor 2 pathway to produce oxidative damage, resulting in apoptosis, which promoted neuroinflammation and neuronal death. Besides, our results suggested that this neurotoxicity was caused by the breakdown of the microbiota-gut-brain axis, mediated by reduced concentrations of dopamine, short chain fatty acids, and intestinal microbial activity induced by climbazole.

Insights into spirotetramat-induced thyroid disruption during zebrafish (Danio rerio) larval development: An integrated approach with in vivo, in vitro, and in silico analyses

Spirotetramat (SPT), a tetronic acid-derived insecticide, is implicated in reproductive and lipid metabolism disorders, as well as developmental toxicity in fish. While these effects are documented, the precise mechanisms underlying its developmental toxicity are not fully elucidated. In this study, zebrafish embryos (2 h post-fertilization, hpf) were exposed to four concentrations of SPT (0, 60, 120, and 240 μg/L) until 21 dpf (days post-fertilization). We delved into the mechanisms by examining its potential disruption of the thyroid endocrine system, employing in vivo, in vitro, and in silico assays. The findings showed notable developmental disturbances, including reduced hatching rates, shortened body lengths, and decelerated heart rates. Additionally, there was an increase in malformations and a decline in locomotor activity. Detailed analyses revealed that SPT exposure led to elevated thyroid hormone levels, perturbed the hypothalamic-pituitary-thyroid (HPT) axis transcript levels, amplified deiodinase type I (Dio1) and deiodinase type II (Dio2) activities, and both transcriptionally and proteomically upregulated thyroid receptor beta (TRβ) in larvae. Techniques like molecular docking and surface plasmon resonance (SPR) confirmed SPT's affinity for TRβ, consistent with in vitro findings suggesting its antagonistic effect on the T3-TR complex. These insights emphasize the need for caution in using tetronic acid-derived insecticides.

Combined toxicity of aflatoxin B1 and tebuconazole to the embryo development of zebrafish (Danio rerio)

Mycotoxins and pesticides are pervasive elements within the natural ecosystem. Furthermore, many environmental samples frequently exhibit simultaneous contamination by multiple mycotoxins and pesticides. Nevertheless, a significant portion of previous investigations has solely reported the occurrence and toxicological effects of individual chemicals. Global regulations have yet to consider the collective impacts of mycotoxins and pesticides. In our present study, we undertook a comprehensive analysis of multi-level endpoints to elucidate the combined toxicity of aflatoxin B1 (AFB1) and tebuconazole (TCZ) on zebrafish (Danio rerio). Our findings indicated that AFB1 (with a 10-day LC50 value of 0.018 mg L-1) exhibits higher toxicity compared to TCZ (with a 10-day LC50 value of 2.1 mg L-1) toward D. rerio. The co-exposure of AFB1 and TCZ elicited synergistic acute responses in zebrafish. The levels of GST, CYP450, SOD, and Casp-9 exhibited significant variations upon exposure to AFB1, TCZ, and their combined mixture, in contrast to the control group. Additionally, eight genes, namely cat, cxcl-cic, il-1β, bax, apaf-1, trβ, ugtlab, and vtg1, displayed marked alterations when exposed to the chemical mixture as opposed to individual substances. Therefore, further exploration of the underlying mechanisms governing joint toxicity is imperative to establish a scientific basis for evaluating the risk associated with the combined effects of AFB1 and TCZ. Moreover, it is essential to thoroughly elucidate the organ system toxicity triggered by the co-occurrence of mycotoxins and pesticides.

Zebrafish Optokinetic Reflex: Minimal Reporting Guidelines and Recommendations

Optokinetic reflex (OKR) assays in zebrafish models are a valuable tool for studying a diverse range of ophthalmological and neurological conditions. Despite its increasing popularity in recent years, there are no clear reporting guidelines for the assay. Following reporting guidelines in research enhances reproducibility, reduces bias, and mitigates underreporting and poor methodologies in published works. To better understand optimal reporting standards for an OKR assay in zebrafish, we performed a systematic literature review exploring the animal, environmental, and technical factors that should be considered. Using search criteria from three online databases, a total of 109 research papers were selected for review. Multiple crucial factors were identified, including larval characteristics, sample size, fixing method, OKR set-up, distance of stimulus, detailed stimulus parameters, eye recording, and eye movement analysis. The outcome of the literature analysis highlighted the insufficient information provided in past research papers and the lack of a systematic way to present the parameters related to each of the experimental factors. To circumvent any future errors and champion robust transparent research, we have created the zebrafish optokinetic (ZOK) reflex minimal reporting guideline.

Occurrence, formation, and proteins perturbation of disinfection byproducts in indoor air resulting from chlorine disinfection

Increased amounts of chlorine disinfectant have been sprayed to inactivate viruses in the environment since the COVID-19 pandemic, and the health risk from chemicals, especially disinfection byproducts (DBPs), has unintentionally increased. In this study, we characterized the occurrence of haloacetic acids (HAAs) and trihalomethanes (THMs) in indoor air and evaluated their formation potential from typical indoor ingredients. Subsequently, the adverse effect of chloroacetic acid on A549 cells was depicted at the proteomic, transcriptional and silico levels. The results revealed that the total concentrations of HAAs and THMs ranged from 1.46 to 4.20 μg/m3 in ten indoor environments. Both classes of DBPs could be generated during the chlorination of prevalent terpenes by competing reactions, which are associated with the volatile state of indoor ingredients after disinfection. The C-type lectin receptor signaling pathway and cellular senescence were significantly perturbed pathways, which interfered with the development of lung fibrosis. The negative effect was further investigated by molecular docking and transcription, which showed that HAAs can interact with four C-type lectin receptor proteins by hydrogen bonds and inhibit the mRNA expression of related proteins. This study highlights the potential secondary biological risk caused by intensive DBPs generated from chlorination and draws our attention to the potential environmental factors leading to chronic respiratory disease.

Development of a simplified human embryonic stem cell-based retinal pre-organoid model for toxicity evaluations of common pollutants

OBJECTIVE

To explore the retinal toxicity of pharmaceuticals and personal care products (PPCPs), flame retardants, bisphenols, phthalates, and polycyclic aromatic hydrocarbons (PAHs) on human retinal progenitor cells (RPCs) and retinal pigment epithelial (RPE) cells, which are the primary cell types at the early stages of retinal development, vital for subsequent functional cell type differentiation, and closely related to retinal diseases.

MATERIALS AND METHODS

After 23 days of differentiation, human embryonic stem cell (hESC)-based retinal pre-organoids, containing RPCs and RPE cells, were exposed to 10, 100, and 1000 nM pesticides (butachlor, terbutryn, imidacloprid, deltamethrin, pendimethalin, and carbaryl), flame retardants (PFOS, TBBPA, DBDPE, and TDCIPP), PPCPs (climbazole and BHT), and other typical pollutants (phenanthrene, DCHP, and BPA) for seven days. Then, mRNA expression changes were monitored and compared.

RESULTS

(1) The selected pollutants did not show strong effects at environmental and human-relevant concentrations, although the effects of flame retardants were more potent than those of other categories of chemicals. Surprisingly, some pollutants with distinct structures showed similar adverse effects. (2) Exposure to pollutants induced different degrees of cell detachment, probably due to alterations in extracellular matrix and/or cell adhesion.

CONCLUSIONS

In this study, we established a retinal pre-organoid model suitable for evaluating multiple pollutants' effects, and pointed out the potential retinal toxicity of flame retardants, among other pollutants. Nevertheless, the potential mechanisms of toxicity and the effects on cell detachment are still unclear and deserve further exploration. Additionally, this model holds promise for screening interventions aimed at mitigating the detrimental effects of these pollutants.

Climbazole causes cell apoptosis and lipidosis in the liver of grass carp

Climbazole, an azole, is widely used in personal care products, pharmaceuticals, and pesticides and is frequently detected in surface water. Climbazole has showed endocrine-disrupting effects. However, the effects of climbazole in fish are still largely unclear. In this study, grass carp (Ctenopharyngodon idella) and liver cell lines (L8824 cells) were treated with climbazole at concentrations ranging from 0.2 to 20 μg/L for 42 days in vivo and 24 h in vitro to evaluate the effects on the liver, respectively. Pathological, biochemical, and gene transcription and expression analyses were conducted to examine the hepatotoxicity. Our results showed that climbazole significantly decreased the hepatosomatic index, caused cell apoptosis in vivo and in vitro, and finally accumulated lipids in the liver. Beside, climbazole increased ROS levels, reduced Nrf2 and Keap1 mRNA and protein levels, and further decreased transcription of Nrf2-dependent downstream antioxidant enzyme genes, causing oxidative stress. Moreover, climbazole increased transcription and protein levels of apoptosis-related genes. Finally, climbazole damaged mitochondrial function and structure, disrupted liver lipid metabolism. Overall, climbazole caused hepatotoxicity, leading to a high ecological risk for aquatic organisms.

Mechanistic insight into the adverse outcome of tire wear and road particle leachate exposure in zebrafish (Danio rerio) larvae

Tire wear particles (TWP) have become the major microplastic pollution in China. Road runoff containing TWP leachate can decrease the eye size and even induced mortality in the aquatic organisms. However, the toxic mechanism of TWP and road particles (RP) leachate on aquatic organisms is still unclear. In this study, the zebrafish embryos were exposed to TWP or RP leachate for 5 days at both environmental relevant and high concentrations. The adverse outcome pathways (AOPs) were screened from individual to molecular levels. The morphological and behavioral analysis demonstrated that the leachate exposure mainly impaired the eye development of zebrafish larvae and inhibited the larval swim behavior and phototactic response, which are the adverse outcomes. The phototransduction modulated by zebrafish retina was significantly down-regulated through transcriptomics and metabolomics analysis. The eye histopathological analysis showed that the decreased thickness of the retinal outer nuclear layer (ONL) and retinal pigmented epithelium (RPE) after leachate exposure were caused by the decreased photoreceptor cells. Moreover, the expression of NR2E3 and TPO genes showed concentration-dependent down-regulation after leachate exposure. The inhibition of photoreceptor cell proliferation was identified as the main reason for photoreceptor cell decrease in zebrafish larval eye. This study, for the first time, uncovered the underlying toxic mechanism of TWP and RP on zebrafish larval eyes.

Identifying potential toxic organic substances in leachates from tire wear particles and their mechanisms of toxicity to Scenedesmus obliquus

Tire wear particles (TWPs) are increasingly being found in the aquatic environment. However, there is limited information available on the environmental consequences of TWP constituents that may be release into water. In this study, TWP leachate samples were obtained by immersing TWPs in ultrapure water. Using high-resolution mass spectrometry and toxicity identification, we identified potentially toxic organic substances in the TWP leachates. Additionally, we investigated their toxicity and underlying mechanisms. Through our established workflow, we structurally identified 13 substances using reference standards. The median effective concentration (EC₅₀) of TWP leachates on Scenedesmus obliquus growth was comparable to that of simulated TWP leachates prepared with consistent concentrations of the 13 identified substances, indicating their dominance in the toxicity of TWP leachates. Among these substances, cyclic amines (EC₅₀: 1.04-3.65 mg/L) were found to be toxic to S. obliquus. We observed significant differential metabolites in TWP leachate-exposed S. obliquus, primarily associated with linoleic acid metabolism and purine metabolism. Oxidative stress was identified as a crucial factor in algal growth inhibition. Our findings shed light on the risk posed by TWP leachable substances to aquatic organisms.

Pollution effects on retinal health: A review on current methodologies and findings

In our daily life, we are exposed to numerous industrial chemicals that may be harmful to the retina, which is a delicate and sensitive part of our eyes. This could lead to irreversible changes and cause retinal diseases or blindness. Current retinal environmental health studies primarily utilize animal models, isolated mammalian retinas, animal- or human-derived retinal cells, and retinal organoids, to address both pre- and postnatal exposure. However, as there is limited toxicological information available for specific populations, human induced pluripotent stem cell (hiPSC)-induced models could be effective tools to supplement such data. In order to obtain more comprehensive and reliable toxicological information, we need more appropriate models, novel evaluation methods, and computational technologies to develop portable equipment. This review mainly focused on current toxicology models with particular emphasis on retinal organoids, and it looks forward to future models, analytical methods, and equipment that can efficiently and accurately evaluate retinal toxicity.

Adsorption of 2-hydroxynaphthalene, naphthalene, phenanthrene, and pyrene by polyvinyl chloride microplastics in water and their bioaccessibility under in vitro human gastrointestinal system

The interaction of microplastics (MPs) and organic pollutants has recently become a focus of investigation. To understand how microplastic residues affect the migration of organic pollutants, it is necessary to examine the adsorption and desorption behavior of organic pollutants on MPs. In this study, integrated adsorption/desorption experiments and theoretical calculations were used to clarify the adsorption mechanism of 2-hydroxynaphthalene (2-OHN), naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR) by polyvinyl chloride microplastics (PVC-MPs). Based on the phenomenological mathematical models, the rate-limiting step for analyte adsorption onto PVC-MPs was adsorption onto active sites (R² = 0.865-0.995). Except for PHE, analyte adsorption isotherms were well described by the Freundlich model (R² = 0.992-0.998), and adsorption thermodynamics showed that analyte adsorption on PVC-MPs was a spontaneous exothermic process (ΔH⁰ < 0; ΔG⁰ < 0). Based on the order of adsorption efficiency of 2-OHN < NAP < PHE < PYR, which is identical to the competitive adsorption experiment, polycyclic aromatic hydrocarbon (PAH) adsorption on PVC-MPs increased as the aromatic ring number increased and the hydroxyl content decreased. The release of 2-OHN (49 %-52 %) from PVC-MPs into the simulated gastrointestinal environment was greater than that of NAP (5.5 %-5.7 %). Theoretical calculations and adsorption tests indicated that hydrophobic interaction was the primary influence on the adsorption of PAHs and their hydroxylated derivatives by PVC-MPs. These findings improve our understanding of MPs' behavior and dangers as pollutant carriers in the aquatic environment and help us develop recommendations for the pollution control of MPs.

Impacts of co-exposure to zearalenone and trifloxystrobin on the enzymatic activity and gene expression in zebrafish

Although humans and animals are usually exposed to combinations of toxic substances, little is known about the interactive toxicity of mycotoxins and farm chemicals. Therefore, we can not precisely evaluate the health risks of combined exposure. In the present work, using different approaches, we examined the toxic impacts of zearalenone and trifloxystrobin on zebrafish (Danio rerio). Our findings showed that the lethal toxicity of zearalenone to embryonic fish with a 10-day LC₅₀ of 0.59 mg L^-1 was lower than trifloxystrobin (0.037 mg L^-1). Besides, the mixture of zearalenone and trifloxystrobin triggered acute synergetic toxicity to embryonic fish. Moreover, the contents of CAT, CYP450, and VTG were distinctly altered in most single and combined exposures. Transcriptional levels of 23 genes involved in the oxidative response, apoptosis, immune, and endocrine systems were determined. Our results implied that eight genes (cas9, apaf-1, bcl-2, il-8, trb, vtg1, erβ1, and tg) displayed greater changes when exposed to the mixture of zearalenone and trifloxystrobin compared with the corresponding individual chemicals. Our findings indicated that performing the risk assessment based on the combined impact rather than the individual dosage response of these chemicals was more accurate. Nevertheless, further investigations are still necessary to reveal the modes of action of mycotoxin and pesticide combinations and alleviate their effects on human health.