Identification of Environmental Compounds That May Trigger Early Female Puberty by Activating Human GnRHR and KISS1R.

There has been an alarming trend toward earlier puberty in girls, suggesting the influence of an environmental factor(s). As the reactivation of the reproductive axis during puberty is thought to be mediated by the hypothalamic neuropeptides kisspeptin and gonadotropin-releasing hormone (GnRH), we asked whether an environmental compound might activate the kisspeptin (KISS1R) or GnRH receptor (GnRHR). We used GnRHR or KISS1R-expressing HEK293 cells to screen the Tox21 10K compound library, a compendium of pharmaceuticals and environmental compounds, for GnRHR and KISS1R activation. Agonists were identified using Ca2+ flux and phosphorylated extracellularly regulated kinase (p-ERK) detection assays. Follow-up studies included measurement of genes known to be upregulated upon receptor activation using relevant murine or human cell lines and molecular docking simulation. Musk ambrette was identified as a KISS1R agonist, and treatment with musk ambrette led to increased expression of Gnrh1 in murine and human hypothalamic cells and expansion of GnRH neuronal area in developing zebrafish larvae. Molecular docking demonstrated that musk ambrette interacts with the His309, Gln122, and Gln123 residues of the KISS1R. A group of cholinergic agonists with structures similar to methacholine was identified as GnRHR agonists. When applied to murine gonadotrope cells, these agonists upregulated Fos, Jun, and/or Egr1. Molecular docking revealed a potential interaction between GnRHR and 5 agonists, with Asn305 constituting the most conservative GnRHR binding site. In summary, using a Tox21 10K compound library screen combined with cellular, molecular, and structural biology techniques, we have identified novel environmental agents that may activate the human KISS1R or GnRHR.

Integrated mRNA- and miRNA-sequencing analyses unveil the underlying mechanism of tobacco pollutant-induced developmental toxicity in zebrafish embryos.

Tobacco pollutants are prevalent in the environment, leading to inadvertent exposure of pregnant females. Studies of these pollutants' toxic effects on embryonic development have not fully elucidated the potential underlying mechanisms. Therefore, in this study, we aimed to investigate the developmental toxicity induced by cigarette smoke extract (CSE) at concentrations of 0.25, 1, and 2.5% using a zebrafish embryo toxicity test and integrated transcriptomic analysis of microRNA (miRNA) and messenger RNA (mRNA). The findings revealed that CSE caused developmental toxicity, including increased mortality and decreased incubation rate, in a dose-dependent manner. Moreover, CSE induced malformations and apoptosis, specifically in the head and heart of zebrafish larvae. We used mRNA and miRNA sequencing analyses to compare changes in the expression of genes and miRNAs in zebrafish larvae. The bioinformatics analysis indicates that the mechanism underlying CSE-induced developmental toxicity was associated with compromised genetic material damage repair, deregulated apoptosis, and disturbed lipid metabolism. The enrichment analysis and RT-qPCR show that the ctsba gene plays a crucial function in embryo developmental apoptosis, and the fads2 gene mainly regulates lipid metabolic toxicity. The results of this study improve the understanding of CSE-induced developmental toxicity in zebrafish embryos and contribute insights into the formulation of novel preventive strategies against tobacco pollutants during early embryonic development.

Divergent perspectives on the synergistic impacts of thermal-chemical stress on aquatic biota within the framework of climate change scenarios.

Climate change, including global warming, leads to rising temperatures in aquatic ecosystems, which is one of the numerous repercussions it brings. Furthermore, water warming can indirectly impact aquatic organisms by modifying the toxicity levels of pollutants. Nevertheless, numerous studies have explored the potential impacts of chemical stress on aquatic biota, but little is known about how such chemicals and toxins interact with climate change factors, especially elevated temperatures. As such, this review paper focuses on exploring the potential effects of thermochemical stress on a wide sector of aquatic organisms, including aquatic vertebrates and invertebrates, in various aquatic ecosystems (freshwater and marine systems). Herein, the objective of this study is to explore the most up-to-date the impact of water warming (without chemical stress) and thermochemical stress on various biochemical and physiological processes in aquatic fauna and how this greatly affects biodiversity and sustainability. Therefore, there is a growing need to understand and evaluate this synergistic mechanism and its potential hazardous impacts. However, we need further investigations and scientific reports to address this serious environmental issue in order to confront anthropogenic pollutants regarding climate change and chemical pollution risks in the near future and subsequently find sustainable solutions for them.

18ß-Glycyrrhetinic acid exerts cardioprotective effects against BPA-induced cardiotoxicity through antiapoptotic and antioxidant mechanisms.

Bisphenol A (BPA) is a synthetic environmental pollutant widely used in industry, as well as is an endocrine disrupting chemicals and has a toxic effects on heart tissue. The aim of this study is to reveal the cardioprotective effects of 18ß-glycyrretinic acid (GA) against BPA-induced cardiotoxicity in rats. In this study, 40 male rats were used and five different groups (each group includes eight rats) were formed. The rats were applied BPA (250 mg/kg b.w.) alone or with GA (50 and 100 mg/kg b.w.) for 14 days. Rats were killed on Day 15 and heart tissues were taken for analysis. GA treatment decreased serum lactate dehydrogenase and creatine kinase MB levels, reducing BPA-induced heart damage. GA treatment showed ameliorative effects against lipid peroxidation and oxidative stress caused by BPA by increasing the antioxidant enzyme activities (glutathione peroxidase, superoxide dismutase, and catalase) and GSH level of the heart tissue and decreasing the MDA level. In addition, GA showed antiapoptotic effect by increasing Bcl-2, procaspase-3, and -9 protein expression levels and decreasing Bax, cytochrome c, and P53 protein levels in heart tissue. As a result, it was found that GA has cardioprotective effects on heart tissue by exhibiting antioxidant and antiapoptotic effects against heart damage caused by BPA, an environmental pollutant. Thus, it was supported that GA could be a potential cardioprotective agent.

Endocrine disruption in crustaceans: New findings and perspectives.

A significant advance has been made, especially during the last two decades, in the knowledge of the effects on crustacean species of pollutants proven to be endocrine disruptors in vertebrates. Such effects have been also interpreted in the light of recent studies on crustacean endocrinology. Year after year, the increased number of reports refer to the effects of endocrine disruptors on several processes hormonally controlled. This review is aimed at summarizing and discussing the effects of several kinds of endocrine disruptors on the hormonal control of reproduction (including gonadal growth, sexual differentiation, and offspring development), molting, and intermediate metabolism of crustaceans. A final discussion about the state of the art, as well as the perspective of this toxicological research line is given.

Toxic effects of combined exposure to cadmium and diclofenac on freshwater crayfish (Procambarus clarkii): Insights from antioxidant enzyme activity, histopathology, and gut microbiome.

In recent years, excessive discharge of pollutants has led to increasing concentrations of cadmium (Cd) and diclofenac (DCF) in water; however, the toxicity mechanism of combined exposure of the two pollutants to aquatic animals has not been fully studied. Procambarus clarkii is an economically important aquatic species that is easily affected by Cd and DCF. This study examined the effects of combined exposure to Cd and DCF on the tissue accumulation, physiology, biochemistry, and gut microflora of P. clarkii. The results showed that Cd and DCF accumulated in tissues in the order of hepatopancreas > gill > intestine > muscle. The hepatopancreas and intestines were subjected to severe oxidative stress, with significantly increased antioxidant enzyme activity. Pathological examination revealed lumen expansion and epithelial vacuolisation in the hepatopancreas and damage to the villous capillaries and wall in the intestine. The co-exposure to Cadmium (Cd) and Diclofenac (DCF) disrupts the Firmicutes/Bacteroidetes (F/B) ratio, impairing the regular functioning of intestinal microbiota in carbon (C) and nitrogen (N) cycling. This disturbance consequently hinders the absorption and utilization of energy and nutrients in Procambarus clarkii. This study offers critical insights into the toxicological mechanisms underlying the combined effects of Cd and DCF, and suggests potential approaches to alleviate their adverse impacts on aquatic ecosystems.

Photosynthetic mechanisms of carbon fixation reduction in rice by cadmium and polycyclic aromatic hydrocarbons.

Environmental pollutants interfere with plant photosynthesis, thus reduce the crop yield and carbon storage capacity of farmland. This study comparatively explored the effects and mechanisms of polycyclic aromatic hydrocarbons (PAHs, e.g., phenanthrene, pyrene, and benzo[a]pyrene) and cadmium (Cd) on the carbon fixation capacity of rice throughout the growth period. Cd posed severer inhibition on the net carbon fixation of rice than PAHs, with the inhibition rates of 1.40-14.8-fold over PAHs at the concentrations of 0.5 or 5 mg/kg soil. Ribulose diphosphate carboxylase/oxygenase (Rubisco) involved in the Calvin cycle was identified as the common target of these pollutants to inhibit the photosynthetic carbon fixation. Further investigation demonstrated that the different inhibitory effects of Cd and PAHs was resulted from their different interference on the dual catalysis function (carboxylation and oxygenation) of Rubisco. Cd disturbed the balance of the intercellular CO2/O2, thus promoting the oxygenation and inhibiting the carboxylation of the substrate of Rubisco. Under the stress of Cd, the downstream metabolites (e.g. glycolate, glyoxylate, and serine) of Rubisco oxygenation were upregulated by over 2.01-3.24-fold, whereas the carboxylation efficiency (Vcmax) was decreased by 5.58-29.3%. Comparatively, PAHs inhibited both the carboxylation and oxygenation by down-regulating the expression of Rubisco coding gene (OsRBCS2, Log2FC < -2). This study broadens the understanding of the mechanisms of different environmental pollutants on the carbon fixation, providing valuable information for the quantitative estimation of their impacts on the farmland carbon sink. The results would be constructive to develop strategies for eliminating the adverse effects of contaminants and assist the carbon-neutral programs.

Identification of organic pollutants and heavy metals in natural rubber wastewater and evaluation its phytotoxicity and cytogenotoxicity.

The natural rubber industry consumes large volumes of water and annually releases wastewater with rich organic and inorganic loads. This wastewater is allowed for soil irrigation in developing countries. However, the pollutant composition in wastewater and its environmental effects remain unclear. Therefore, we aimed to assess the wastewater's physicochemical parameters, toxic organic pollutants, heavy metals, and phytotoxic and cytogenotoxic. The result revealed that values of comprehensive wastewater parameters were recorded as chemical oxygen demand (187432.1 mg/L), pH (4.23), total nitrogen (1157.1 mg/L), ammonia nitrogen (1113.0 mg/L), total phosphorus (1181.2 mg/L), Zn (593.3 mg/L), Cr (0.6127 mg/L), and Ni (0.2986 mg/L). The organic compounds detected by LC-MS were salbostatin, sirolimus, Gibberellin A34-catabolite, 1-(sn-glycero-3-phospho)-1D-myo-inositol, and methyldiphenylsilane. The toxicity of the identified toxic chemicals and heavy metals was confirmed by onion and mung bean phytotoxicity characterization tests. The wastewater affected the germination of mung bean seeds, reduced or inhibited the growth of onions, and induced various chromosomal aberrations in root apical meristems. Our study shows that the treatment of natural rubber wastewater needs to be improved, and the feasibility of irrigating soil with wastewater needs to be reconsidered.

A 4-year study of bovine reproductive hormones that are induced by pharmaceuticals and appear as steroid estrogenic pollutants in the resulting slurry, using in vitro and instrumental analytical methods.

The main objective of the research was to study the environmental "price" of the large-scale, milk production from a rarely known perspective, from the mapping of the estrogenic footprint (the amount of oestrus-inducer hormonal products, and the generated endoestrogens) in the resulting slurry in a dairy cow farm. These micropollutants are endocrine-disrupting chemicals (EDCs) and can be dangerous to the normal reproductive functions even at ng/kg concentration. One of them, 17ß-estradiol, has a 20,000 times stronger estrogenic effect than bisphenol-A, a widely known EDC of industrial origin. While most studies on EDCs are short-term and/or laboratory based, this study is longitudinal and field-based. We sampled the slurry pool on a quarterly basis between 2017 and 2020. Our purpose was testing the estrogenic effects using a dual approach. As an effect-based, holistic method, we developed and used the YES (yeast estrogen screen) test employing the genetically modified Saccharomyces cerevisiae BJ3505 strain which contains human estrogenic receptor. For testing exact molecules, UHPLC-FLD was used. Our study points out that slurry contains a growing amount of EDCs with the risk of penetrating into the soil, crops and the food chain. Considering the Green Chemistry concept, the most benign ways to prevent of the pollution of the slurry is choosing appropriate oestrus-inducing veterinary pharmaceuticals (OIVPs) and the separation of the solid and liquid parts with adequate treatment methods. To our knowledge, this is the first paper on the adaptation of the YES test for medicine and slurry samples, extending its applicability. The adapted YES test turned out to be a sensitive, robust and reliable method for testing samples with potential estrogenic effect. Our dual approach was successful in evaluating the estrogenic effect of the slurry samples.

Response to gallium (Ga) exposure and its distribution in rice plants.

Root architecture is the temporal and spatial configuration of root system in the heterogeneous matrix of soil that is prone to chemical stresses. Gallium (Ga) is among the emerging chemical pollutants that are mostly associated with high-tech industries, specifically associated with semiconductors. In view of its potential risk and increasing distribution in the environment, this study was designed to evaluate the inhibition rate, Ga distribution in different tissues, and root architecture of rice seedlings under different concentrations of Ga. We observed that 2.59, 46.7, and 168.2 mg Ga/L were minimum (EC20), medium (EC50), and maximum (EC75) effective concentrations for rice plants that corresponded to the 20, 50, and 75% inhibition on the relative growth rate, respectively. Distribution of Ga in rice tissues showed that accumulation of Ga was much higher in roots than shoots of rice seedlings, and it increased with an increase in Ga doses. Evan blue staining technique reveals that the number of damaged/dead cell was dose-dependent on Ga. Moreover, several traits associated with root system architecture demonstrating that rice root system architecture altered in response to Ga stress. Collectively, the results reveal that Ga exposure inhibited the growth and development of rice plants. This study will enhance our understanding that how different concentrations of Ga in the environment can affect plants; however, more comprehensive studies are essential to further determine plant response against Ga stress.

The comparative effects of visible light and UV-A radiation on the combined toxicity of P25 TiO2 nanoparticles and polystyrene microplastics on Chlorella sp.

The ubiquitous presence of TiO2 nanoparticles (nTiO2) and microplastics (MPs) in marine ecosystems has raised serious concerns about their combined impact on marine biota. This study investigated the combined toxic effect of nTiO2 (1 mg/L) and NH2 and COOH surface functionalized polystyrene MPs (PSMPs) (2.5 and 10 mg/L) on Chlorella sp. All the experiments were carried out under both visible light and UV-A radiation conditions to elucidate the impact of light on the combined toxicity of these pollutants. Growth inhibition results indicated that pristine nTiO2 exhibited a more toxic effect (38%) under UV-A radiation when compared to visible light conditions (27%). However, no significant change in the growth inhibitory effects of pristine PSMPs was observed between visible light and UVA radiation conditions. The combined pollutants (nTiO2 + 10 mg/L PSMPs) under UV-A radiation exhibited more growth inhibition (nTiO2 + NH2 PSMPs 66%; nTiO2 + COOH PSMPs 50%) than under visible light conditions (nTiO2 + NH2 PSMPs 55%; TiO2 + COOH PSMPs 44%). Independent action modeling indicated that the mixture of nTiO2 with PSMPs (10 mg/L) exhibited an additive effect on the algal growth inhibition under both the light conditions. The photoactive nTiO2 promoted increased production of reactive oxygen species under UV-A exposure, resulting in cellular damage, lipid peroxidation, and impaired photosynthesis. The effects were more pronounced in case of the mixtures where PSMPs added to the oxidative stress. The toxic effects of the binary mixtures of nTiO2 and PSMPs were further confirmed through the field emission electron microscopy, revealing specific morphological abnormalities. This study provides valuable insights into the potential risks associated with the combination of nTiO2 and MPs in marine environments, considering the influence of environmentally relevant light conditions and the test medium.

Association between exposure to persistent organic pollutants and pubertal timing in boys and girls: A systematic review and meta-analysis.

In recent years, the phenomenon of abnormal pubertal timing in children has become increasingly common worldwide. Persistent organic pollutants (POPs) may be one of the risk factors contributing to this phenomenon, but the relationship between them is unclear based on current evidence. The purpose of this study was to determine the association of POPs exposure with pubertal timing in girls and boys by conducting a systematic review and meta-analysis. We searched PubMed and Embase databases for studies before June 1, 2023. Meta-analysis was performed by pooling relative risk (RR) or odds ratio (OR) or prevalence ratio (PR) or hazard ratio (HR) estimates with 95 % confidence intervals (CIs). Subgroup analysis, publication bias assessment and sensitivity analysis were also carried out. A total of 21 studies were included, involving 2479 boys and 8718 girls. The results of meta-analysis showed that exposure to POPs was significantly associated with delayed pubertal timing in girls (RR: 0.85; 95 % CI: 0.79-0.91; p < 0.001). There was no statistically significant association between exposure to POPs and pubertal timing in boys (RR: 1.18; 95 % CI: 0.99-1.40; p = 0.070). Subgroup analysis showed that there may be gender differences in the effects of exposure to POPs on pubertal timing. Our results suggested that exposure to POPs could delay pubertal timing in girls. However, based on current evidence, no significant association was found between POPs exposure and pubertal timing in boys.

Research advances on impacts micro/nanoplastics and their carried pollutants on algae in aquatic ecosystems: A review.

The widespread presence of micro/nanoplastics in aquatic ecosystems has certainly affected ecosystem functions and food chains/webs. The impact is worsened by the accumulation of different pollutants and microorganisms on the surface of microplastics. At the tissue, cellular, and molecular levels, micro/nanoplastics and the contaminants they carry can cause damage to aquatic organisms. Problematically, the toxic mechanism of micro/nanoplastics and contaminants on aquatic organisms is still not fully understood. Algae are key organisms in the aquatic ecosystem, serving as primary producers. The investigation of the toxic effects and mechanisms of micro/nanoparticles and pollutants on algae can contribute to understanding the impact on the aquatic ecosystem. Micro/nanoplastics inhibit algal growth, reduce chlorophyll and photosynthesis, induce ultrastructural changes, and affect gene expression in algae. The effects of energy flow can alter the productivity of aquatic organisms. The type, particle size, and concentration of micro/nanoparticles can influence their toxic effects on algae. Although there has been some research on the toxic effects of algae, the limited information has led to a significant lack of understanding of the underlying mechanisms. This paper provides a comprehensive review of the interactions between micro/nanoplastics, pollutants, and algae. The effects of various factors on algal toxicity are also analyzed. In addition, this article discusses the combined effects of microplastics, global warming, and oil pollution on algae and aquatic ecosystems in the context of global change. This research is of great importance for predicting future environmental changes. This review offers a more comprehensive understanding of the interactions between microplastics/nanoplastics and algae, as well as their impact on the carbon cycle.

Warmer temperature overrides the effects of antidepressants on amphibian metamorphosis and behavior.

Climate change can exacerbate the effects of environmental pollutants on aquatic organisms. Pollutants such as human antidepressants released from wastewater treatment plants have been shown to impact life-history traits of amphibians. We exposed tadpoles of the wood frog Lithobates sylvaticus to two temperatures (20 °C and 25 °C) and two antidepressants (fluoxetine and venlafaxine), and measured timing of metamorphosis, mass at metamorphosis, and two behaviors (startle response and percent motionless). Antidepressants significantly shortened time to metamorphosis at 20 °C, but not at 25 °C. At 25 °C, tadpoles metamorphosed significantly faster than those at 20 °C independent of antidepressant exposure. Venlafaxine reduced body mass at 25 °C, but not at 20 °C. Temperature and antidepressant exposure affected the percent of tadpoles showing a startle response. Tadpoles at 20 °C displayed significantly more responses than at 25 °C. Exposure to fluoxetine also increased the percent of tadpoles showing a startle response. Venlafaxine reduced the percent of motionless tadpoles at 25 °C but not at 20 °C. While our results showed that antidepressants can affect the timing of metamorphosis in tadpoles, warmer temperatures overrode these effects and caused a reduction in an important reaction behavior (startle response). Future studies should address how warmer global temperatures may exacerbate or negate the effects of environmental pollutants.

Effects of exposure to the explosive and environmental pollutant 2,4,6-trinitrotoluene on ovarian follicle development in rats.

Although 2,4,6-trinitrotoluene (TNT) is a dangerous carcinogen in environmental pollution, information on the reproductive effects of TNT explosive contamination is limited. To explore the possible ovarian effects, TNT explosive-exposed rat models were established, and Wistar female rats were exposed to low and high TNT (40 g and 80 g, air and internal) explosives. After a month of exposure, the estrous cycle, ovarian histopathology, and follicle counting were conducted. Serum hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), progesterone, testosterone, and estradiol were detected, and the mRNA and protein expression of steroidogenic enzymes were measured. The results showed that the diestrus phase duration was significantly (P < 0.05) increased in the high TNT-exposed groups. In addition, the proportions of preantral follicles were significantly (P < 0.05) decreased in the high TNT-exposed groups, as well as the proportions of atretic follicles. The serum estradiol levels were significantly (P < 0.05) increased, and the follicle-stimulating hormone and luteinizing hormone levels were significantly (P < 0.05) decreased in the high TNT-exposed groups. The mRNA levels of steroidogenic acute regulatory protein (Star), cytochrome P450 cholesterol side chain cleavage (Cyp11a1, Cyp17a1 and Cyp19a1), hydroxysteroid dehydrogenase 3b (Hsd3b) and steroidogenic factor-1 (SF-1) were significantly (P < 0.05) increased in the TNT-exposed groups. The protein levels of Star, Cyp11a1 and Hsd3b were increased (P < 0.05) in the TNT-exposed groups. These results indicate that the exposure of rats to TNT explosive can subsequently affect ovarian follicle development, suggesting that the mechanism may involve disrupting steroidogenesis.

Associations between PFAS concentrations and the oxidative status in a free-living songbird (Parus major) near a fluorochemical facility.

For the past 7 decades, PFAS have been used in many different products and applications, which has led to a widespread contamination of these compounds. Nevertheless at present, little is known about the effects of these compounds on avian wildlife. Therefore, this study investigated associations between PFAS concentrations in the plasma and the oxidative status (i.e. non-enzymatic antioxidants and biomarkers of oxidative stress) in great tits at two sites near a fluorochemical manufacturing facility. Different PFAS were detected in the blood plasma with a mean ΣPFAS of 16062 pg/µL at the site closest to the facility. The PFAS profile in the plasma consisted mainly of PFOS, PFOA, PFDA and PFDoDA, where concentrations were higher for these compounds at the site closest to the plant. Our results show a clear link between PFAS and the antioxidant status of the birds; total antioxidant capacity and peroxidase activity were higher near the plant site, while the glutaredoxin activity was higher further away. Additionally, positive associations were found between PFDoDA and glutathione-S-transferase activity, between PFOS and glutathione-S-transferase activity, between PFDA and peroxidase activity, and between PFOS and peroxidase activity. Lastly, a negative association was found between plasma PFDA concentrations and the total polyphenol content. Interestingly, malondialdehyde levels did not differ between sites, suggesting lipid peroxidation was not affected. Although our results suggest that great tits with elevated PFAS concentrations did not suffer oxidative damage, the antioxidant defence responses were significantly triggered by PFAS exposure. This implies that the great tits have managed to defend themselves against the possible oxidative damage coming from PFAS contamination, although the upregulated antioxidant defences may have fitness costs. Further, experiments are needed to investigate the specific mechanisms by which PFAS induce oxidative stress in avian species.

Interactions between phenanthrene and polystyrene micro/nano plastics: Implications for rice (Oryza sativa L.) toxicity.

Micro/nano plastics (MPs/NPs) are widely distributed and are one of the global pollutants of current concern. Micro/nano plastics can adsorb a variety of persistent organic pollutants, and different particle sizes and surface charges affect the biological effects of MPs/NPs. Therefore, how the compound pollution of MPs/NPs with different particle sizes and organic pollutants produces toxic effects on plants needs to be further studied. We investigated the toxic effects of phenanthrene (Phe) and amino-modified PS (PS-NH2) with two particle sizes (50 nm, 5 µm) on rice. The stress mechanism of PS-NH2 was different between the two particle sizes. Moreover, 50 nm PS-NH2 inhibited stomatal conductance and transpiration rate, reduced photosynthetic rate, significantly enriched GO functions such as "DNA repair" and "DNA double-strand break," and caused severe DNA damage in rice. Notably, 5 µm PS-NH2 affected the gene expression of "photosynthetic lighting" and "photosynthetic antenna protein" in rice, decreased chlorophyll content, and inhibited rice growth. The toxicity of 50 nm PS-NH2 was stronger. In addition, we found that Phe reduced the toxicity of PS-NH2 with different particle sizes, and the relief effect of 50 nm PS-NH2+Phe was more evident. Further, 50 nm PS-NH2+Phe alleviated the toxicity by stimulating the activities of antioxidant enzymes, reducing oxidative damage to chloroplasts, and inhibiting photosynthesis. However, 5 µm PS-NH2+Phe can reduce the stress by reducing the degree of membrane lipid peroxidation, activating metabolic pathways related to the cell wall and cell membrane formation, and plant antitoxin biosynthesis. The results contribute to the understanding of the mechanism of toxicity of MPs/NPs and polycyclic aromatic hydrocarbons (PAHs) to crops.

Toxic effects of four emerging pollutants on cardiac performance and associated physiological parameters of the thick-shell mussel (Mytilus coruscus).

Robust cardiac performance is critical for the health and even survival of an animal; however, it is sensitive to environmental stressors. At present, little is known about the cardiotoxicity of emerging pollutants to bivalve mollusks. Thus, in this study, the cardiotoxic effects of four emergent pollutants, carbamazepine (CBZ), bisphenol A (BPA), tetrabromobisphenol A (TBBPA), and tris(2-chloroethyl) phosphate (TCEP), on the thick-shell mussel, Mytilus coruscus, were evaluated by heartbeat monitoring and histological examinations. In addition, the impacts of these pollutants on parameters that closely related to cardiac function including neurotransmitters, calcium homeostasis, energy supply, and oxidative status were assessed. Our results demonstrated that 28-day exposure of the thick-shell mussel to these pollutants resulted in evident heart tissue lesions (indicated by hemocyte infiltration and myocardial fibrosis) and disruptions of cardiac performance (characterized by bradyrhythmia and arrhythmia). In addition to obstructing neurotransmitters and calcium homeostasis, exposure to pollutants also led to constrained energy supply and induced oxidative stress in mussel hearts. These findings indicate that although do differ somehow in their effects, these four pollutants may exert cardiotoxic impacts on mussels, which could pose severe threats to this important species and therefore deserves more attention.

Multigenerational effects of co-exposure to dimethylarsinic acid and polystyrene microplastics on the nematode Caenorhabditis elegans.

In the current study, we assessed the impact of DMA (dimethylarsinic acid) and MPs (microplastics) interactions in C. elegans over the course of five generations. We found that the redox state of the organisms changed over generations as a result of exposure to both pollutants. From the third generation onward, exposure to MPs reduced GST activity, indicating reduced detoxifying abilities of these organisms. Additionally, dimethylarsinic exposure decreased the growth of organisms in the second, fourth, and fifth generations. In comparison to isolated pollutants, the cumulative effects of co-exposure to DMA and MPs seem to have been more harmful to the organisms, as demonstrated by correlation analysis. These findings demonstrate that DMA, despite being considered less hazardous than its inorganic equivalents, can still have toxic effects on species at low concentrations and the presence of MPs, can worsen these effects.

Exposure to phthalate metabolites, bisphenol A, and psychosocial stress mixtures and pregnancy outcomes in the Atlanta African American maternal-child cohort.

BACKGROUND: Consumer products are common sources of exposure for phthalates and bisphenol A (BPA), which disrupt the endocrine system. Psychosocial stressors have been shown to amplify the toxic effects of endocrine disruptors but, information is limited among African Americans (AAs), who experience the highest rates of adverse pregnancy outcomes and are often exposed to the highest levels of chemical and non-chemical stressors. We examined the association between an exposure mixture of phthalate metabolites, BPA, and psychosocial stressors with gestational age at delivery and birthweight for gestational age z-scores in pregnant AA women. STUDY DESIGN: Participants were enrolled in the Atlanta African American Maternal-Child Cohort (N = 247). Concentrations of eight phthalate metabolites and BPA were measured in urine samples collected at up to two timepoints during pregnancy (8-14 weeks gestation and 20-32 weeks gestation) and were averaged. Psychosocial stressors were measured using self-reported, validated questionnaires that assessed experiences of discrimination, gendered racial stress, depression, and anxiety. Linear regression was used to estimate individual associations between stress exposures (chemical and psychosocial) and birth outcomes. We leveraged quantile g-computation was used to examine joint effects of chemical and stress exposures on gestational age at delivery (in weeks) and birthweight for gestational age z-scores. RESULTS: A simultaneous increase in all phthalate metabolites and BPA was associated with a moderate reduction in birthweight z-scores (mean change per quartile increase = -0.22, 95% CI = -0.45, 0.0). The association between our exposure mixture and birthweight z-scores became stronger when including psychosocial stressors as additional exposures (mean change per quantile increase = -0.35, 95% CI = -0.61, -0.08). Overall, we found null associations between exposure to chemical and non-chemical stressors with gestational age at delivery. CONCLUSIONS: In a prospective cohort of AA mother-newborn dyads, we observed that increased prenatal exposure to phthalates, BPA, and psychosocial stressors were associated with adverse pregnancy outcomes.