Ecotoxicology and Environmental Safety最新文献

Organophosphate flame retardants (OPFRs) are a class of substances that pose potential risks to human health and ecosystems due to their large-scale production, wide range of applications, and ubiquitous presence in the environment. With their potential for long-range atmospheric transport (LRAT), OPFR pollution in high-altitude areas has become an increasing concern. Herein, a general pretreatment method for OPFRs across various sample matrices was established and combined with gas chromatography-mass spectrometry (GC-MS), utilizing a programmed temperature ramp in the vaporization chamber to enable high-throughput detection of OPFRs in various environmental matrices. OPFRs were quantified in soil, grass, tree bark, and wild rat liver samples collected from Qinghai, China (elevation: 2657-4635 m), and their occurrence and bioaccumulation behaviors were systematically investigated. All samples were contaminated with OPFRs, with ∑OPFR concentrations showing the trend of rat liver (mean: 439 ng/g, median: 420 ng/g) > grass (mean: 338 ng/g, median: 273 ng/g) > soil (mean: 190 ng/g, median: 162 ng/g) > tree bark (mean: 125 ng/g, median: 116 ng/g). Paired sample Spearman correlation analysis showed that soil ∑OPFRs were significantly positively correlated with grass ∑OPFRs (P = 0.0023), indicating that soil is the main source of OPFRs in grass. Among soil, grass, tree bark, and rat liver samples, tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP) had the highest contribution rates to ∑OPFRs, with cumulative contributions of 60.9 %, 48.6 %, 76.5 %, and 71.1 %, respectively, indicating that the proportion of industrial sources of OPFRs reaching this area through LRAT is relatively high. Biomagnification factor (BMF) analysis revealed that ∑OPFRs exhibited significant bioaccumulation and biomagnification effects within the soil-grass-rat terrestrial food chain. The ecological risk assessment results indicated that ∑OPFRs in the soil of the study area pose a high ecological risk, with aryl-OPFRs posing the greatest risk. Our findings provide a crucial foundation for further investigation into the contamination and bioaccumulation characteristics of OPFRs in high-altitude regions.

Harmful algal blooms (HABs), exacerbated by climate change and environmental disturbances, pose global challenges due to marine toxin contamination, particularly diarrhetic shellfish toxins (DSTs). DSTs are prevalent marine toxins, and understanding their synthesis is vital for managing fisheries and mitigating environmental triggers. This study delves into the synthesis mechanisms of DSTs in Prorocentrum arenarium and Prorocentrum lima, which vary in toxin types and concentrations. We conducted a comprehensive comparative transcriptomic analysis to identify potential toxin-related genes, focusing on polyketide synthases (PKSs) and fatty acid synthases (FASs). Our research predicted 96 PKSs and 91 FASs genes, with a detailed examination of their sequences to elucidate dinophysistoxins (DTXs) synthesis. Additionally, we analyzed differential gene expression of PKSs in P. arenarium under nitrogen and phosphorus-limited conditions, revealing a correlation between specific PKSs gene expression patterns and okadaic acid (OA) content variations. These findings suggest a potential role of the fatty acid biosynthesis pathway in DSTs synthesis. While not completely uncovering the biosynthetic pathway of DSTs, our study offers crucial insights and genomic resources for future research on dinoflagellate toxin production mechanisms.

Population exposure to plastics is increasing, and plasticizers are frequently detected in humans as important ingredients of plastic products. However, patterns of exposure to harmful ingredients of plastics and their effects on neurofilament light chain (NFL), a marker of active brain pathology, are currently inconclusive. Herein, we employed a range of statistical methods to thoroughly investigate the impact of 24 plastic hazardous ingredients and their varying exposure patterns on NFL concentrations in the blood of the general population in 533 participants. Generalized linear model revealed a positive correlation between Mono-isononyl phthalate and Mono (2-Ethyl- 5-Hydroxyhexyl) Phthalate (MEHHP) with NFL. Furthermore, a significant dose-response relationship was observed between MEHHP and NFL, while Butyl paraben and Mono (Hydroxy-Isononyl) Ester exhibited a distinct "inverted U-shaped" nonlinear pattern with NFL. Additionally, Weighted Quantile Sum model allowed us to identify the mixed effects of all 24 plastic hazardous ingredients, with Mono(2-Ethyl-5-Oxohexyl) Phthalate, Mono-isobutyl phthalate, Mon butyl Phthalate, Propyl paraben and Triclosan occupying prominent positions. Finally, the latent profile analysis categorized exposures into high, medium, and low patterns, confirming that higher exposure to plastic hazardous ingredients posed a significant risk factor for elevated NFL levels in the blood. Exposure to plastic hazardous ingredients significantly increases the risk of NFL, the present contributes to early detection and intervention to reduce the incidence of neurodevelopmental disorder.

Nonalcoholic fatty liver disease (NAFLD) is recognized as a significant public health problem worldwide. Several clinical studies have investigated the associations between Per- and poly-fluoroalkyl substances (PFAS) compounds with the risk of NAFLD in general adults, but the mediating effect of triglycerides (TG) was remained unexplored. In this study, 6990 individuals from the National Health and Nutrition Examination Survey (NHANES, 2003-2018) database were enrolled. Firstly, the results of generalized linear models (GLM) and restricted cubic splines (RCS) revealed positive associations of PFAS compounds with NAFLD risk score and liver function, and nearly linear E-R curves indicated no safe threshold. Meanwhile, weighted quantile sum (WQS) regression demonstrated the relationships between PFAS mixtures with NAFLD risk score and liver function, as well as perfluorooctanoic acid (PFOA) was identified as the main contributor to the increased NAFLD risk. Then, mediation analysis was conducted to explore whether serum lipids mediate the relationships. It further highlighted significant mediation effects of TG, with the mediated proportion ranging from 10.4 % to 42.9 %. Finally, sensitivity and stratified analyses were performed, confirming the reliability of these findings. Notably, significant associations were observed in individuals with a BMI ≥ 28, highlighting that these relationships were particularly evident in obese participants. In conclusion, our study suggested that PFAS mixtures exposure may influence NAFLD risk score by mediating TG in human metabolism. This result could provide more comprehensive epidemiological evidence and guide clinical applications.

Phenols and parabens, as endocrine-disrupting chemicals (EDCs), are prevalent in daily consumer products and industrial applications. Folate, a vital vitamin, plays a crucial role in numerous metabolic processes. The interaction between EDCs and folate is not well understood and warrants investigation. We utilized data from the National Health and Nutrition Examination Survey (NHANES) 2005-2016. Since many pollutants are co-exposed congeners, with interactive effects between pollutants, we employed multivariate linear regression model, weighted quantile sum regression, and Bayesian kernel machine regression (BKMR) to quantify the impact of folate levels in serum and red blood cell (RBC) and the overall effects of combined exposures. The study included 4395 children and adolescents. A negative correlation was observed between RBC folate concentrations and urinary concentrations of Bisphenol A (BPH), Triclosan (TRS), Methyl paraben (MPB), Propyl paraben (PPB), and Butyl paraben (BUP), in children and adolescents. Specifically, an increase in RBC folate levels was linked to a decrease in urinary BPH, TRS, MPB, PPB, and BUP concentrations. Similar associations were found with serum folate. The weighted quantile sum index showed a decrease in both RBC and serum folate levels with an increase in the mixture of phenols and parabens. BKMR further supported the overall negative impact of the chemical mixture on folate levels. This study provides evidence of an inverse relationship between exposure to phenols and parabens and folate concentrations in children and adolescents, which would be of significance in providing guidance for clinical interventions and calling for remediation actions to be prioritized during childhood.

Global warming-induced permafrost thawing raises concerns about the release of dormant microbes, including potentially harmful plant pathogens. However, the potential pathogenic risks associated with the thawing of permafrost remain poorly understood. Here, we conducted a 90-day soil incubation experiment at 4 °C to mimic extended permafrost thawing in Alaskan tundra soils stratified into active (A), transitional (T), and permanently frozen (P) layers. Following incubation, we examined the changes in bacterial abundance and community composition and tested the reactivation and pathogenicity of dormant plant pathogenic bacteria. Bacterial abundance, measured by colony-forming units and 16S rRNA gene copies, distinctly increased in the T and P layers after thawing. These layers also exhibited substantial shifts in bacterial community structure, with Fe-cycling taxa becoming more abundant and permafrost-dominant taxa decreasing in abundance. Notably, we isolated 52 strains with proteolytic activity, and our pathogenicity tests confirmed that Pseudomonas spp. isolates caused potato soft rot symptoms. Some Pseudomonas pathogens were undetectable in the amplicon sequencing data before thawing and emerged only in the thawed T and P layers. Our findings illustrate that permafrost acts as a reservoir of potential plant pathogens, and their resurgence upon thawing poses a potential risk to Arctic ecosystems.

The effects of microplastic (MP) accumulation in freshwaters on organisms and ecosystem functions are poorly understood, as are the roles of MP particle properties in regulating these effects. In freshwater microcosms, we quantified variation in microbial communities and ecosystem functions and compared effects of MP concentration (0, 1000, 50000 particles/kg_sediment), shape (sphere, fragment, fibre), and polymer (polyethylene, polyethylene terephthalate, polypropylene, polystyrene) with those of a model invertebrate consumer (Chironomus riparius). We detected multiple effects of specific MP properties, especially associated with MP fragments and fibres, and the polymer polypropylene. These effects included increases in microbial abundance, consumer biomass and ecosystem respiration, as well as decreases in microbial enzyme activity and water chlorophyll-a. MP presence was also associated with increased relative abundance of microbial taxa reported to degrade plastics. However, consumer presence mostly had stronger effects (effect sizes ranging from ± 11 -313 %) than MP exposure (effect sizes ranging from ± 1-89 %) on microbial communities and ecosystem functions. Furthermore, several MP effects were only detected when chironomid consumers were absent. Overall, our findings suggest that MP effects on microbes and ecosystem functions are often relatively small and variable, depending on particle properties and consumer presence. Nevertheless, the number of MP effects detected highlights the need for further investigations of interactions between MPs and other environmental drivers, to more thoroughly assess the risks of MP pollution for freshwater ecosystems.

Pollinators are exposed to multiple pesticides during their lifetime. Various pesticides are used in agriculture and thus not all mixtures have been tested against each other and little is known about them. In this article, we investigate the impact of sulfoxaflor, a novel sulfoximine insecticide, and azoxystrobin, a widely used strobilurin fungicide, on bumble bee Bombus terrestris worker survival and physiological functions. The dosages used in this experiment are selected from dose response experiments based on LD₅₀ data. Due to variable interactive effects on survival, our findings reveal distinct effects on bumble bee metabolic rate and respiratory patterns induced by sulfoxaflor in combination with azoxystrobin, shedding light on previously unexplored aspects of its physiological impact. Notably, we observed noteworthy differences between oral and contact treatments, emphasizing the importance of considering distinct application methods when evaluating pesticide effects and interactions. Specifically, our results indicate that azoxystrobin can mitigate the impact of sulfoxaflor, suggesting dose-dependent antagonistic interaction between these pesticides in contact exposure. In oral exposure, however, Amistar tended to potentiate the sulfoxaflor effect. This study contributes valuable insights into the multifaceted dynamics of pesticide exposure and interactions, paving the way for a more nuanced understanding of their implications on pollinator health.

The increasing exposure to biomass-burning emissions underscores the need to understand their toxicological impacts on human health. In this study, we developed a laboratory model to evaluate the effects of single and repeated sub-acute exposures to water-soluble wood tar (WT) extracts, a product of biomass burning, on human lung, liver, and immune cells. Using representative cell lines for different tissues, we examined the cytotoxic effects under conditions mimicking sub-acute environmental exposure levels relevant to humans. Our findings indicate that repeated sub-acute exposures to water-soluble WT extracts significantly enhance the inflammatory response, evidenced by increased IL6, IL8, and TNFa cytokine levels, compared to a single exposure. Additionally, oxidative stress responses were more pronounced with increased lipid peroxidation and HMOX1, GCLC and CYP1A1 gene expression following repeated exposures. Metabolomics analyses of polar and lipid metabolites revealed changes related to energy production and consumption that emerge even after a single exposure at sub-acute levels and vary across different cell types representing the different tissues. Impaired cellular respiration, measured by oxygen consumption rate, corroborates the observed changes. These results provide important insights into the cellular mechanisms driving the response to biomass-burning exposure and highlight the potential health risks associated with sub-acute exposure to environmental pollutants.

The global issue of insecticide resistance among pests is a major concern. Ectropis grisescens Warren (Lepidoptera: Geometridae), is a highly destructive leaf-eating pest distributed in tea plantations throughout China and Japan, and has exhibited resistance to various insecticides. Recent studies suggest that insect symbionts play a role in influencing insecticide resistance, however, their specific involvement in E. grisescens remains unclear. Here, we initially selected appropriate antibiotic mixtures at a concentration of 300 μg ml^-1. The bioassay results showed that the insecticide susceptibility of the E. grisescens population treated with antibiotic mixtures significantly increased exposed to bifenthrin. Comparative analysis revealed that the LC₅₀ value, survival rate, P450 enzyme activity, and relative content of Wolbachia in the E. grisescens population treated with 300 μg ml^-1 tetracycline were notably lower than those treated with other antibiotics (ampicillin, gentamicin, and streptomycin). Moreover, the population treated with 2.5 mg ml^-1 tetracycline exhibited even greater reductions in these parameters than the 300 μg ml^-1 tetracycline-treated group. Additionally, 16S rRNA sequencing results showed a significant decrease in xenobiotics metabolism by cytochrome P450 in the E. grisescens population treated with 2.5 mg ml^-1 tetracycline. Transcriptome analysis showed a significant down-regulation of two cytochrome P450 genes in E. grisescens population without Wolbachia. These results suggest that Wolbachia may contribute to the resistance of E. grisescens to bifenthrin by regulating cytochrome P450 genes, providing a foundation for further study on the mechanism of symbiont-mediated host detoxification metabolism in insect pests.