Household insecticide is largely used for insect and ectoparasite control, in city centers as well as in the countryside. The pyrethroids are the most used class of insecticide, these compounds in low doses have low toxicity for mammalians, in comparison to other compounds, with insecticide effects. The contact of these compounds in sublethal doses begins in early life and many cases, in intrauterine life. Considerable diseases still with undefined etiology, such as neurodegenerative conditions, and Huntington's Disease (HD) is one of them. HD is related to overexpression of Polyglutamine (PolyQ40), its aggregation, and non-solubilization, which leads to neural, behavioral, and cognitive damage. In our study, we evaluate the effect of two sublethal doses of a prallethrin-based insecticide (P-BI), in three different Caenorhabditis elegans life stages transgenerational, neonatal, and lifespan. We evaluated the Body bends and pharyngeal pumping rate, and social feeding as behavioral biomarkers. As well as acetylcholinesterase activity (AChE), PolyQ40 aggregation, antioxidant enzymes, and heat shock protein (HSP) expression. We observe that the toxic effect of P-BI is more pronounced on transgenerational and lifespan exposure. Both sublethal doses of P-BI decreased the AChE activity and retard the HSP expression as well as increased the PolyQ40 aggregates indicating a clear biomarker for possible effect in the progression of the HD, by the environmental contamination.

Synthetic azo dyes are extensively used in the textile industries, which are being released as textile effluent into the environment presence of azo dyes in the environment is great environmental concern therefore treatment of textile effluent is crucial for proper release of the effluent into the environment. Electrochemical oxidation (EO) is extensively used in the degradation of pollutants because of its high efficiency. In this study, photo-assisted electrooxidation (PEO) followed by biodegradation of the textile effluent was evaluated. The pretreatment of textile effluent was conducted by EO and PEO in a tubular flow cell with TiO₂–Ti/IrO₂–RuO₂ anode and titanium cathode under different current densities (10, 15, and 20 mA cm⁻²). The chemical oxygen demand level reduced from 3150 mg L⁻¹ to 1300 and 600 mg L⁻¹under EO and PEO, respectively. Furthermore, biodegradation of EO and PEO pretreated textile effluent shows reduction in chemical oxygen demand (COD) from 1300 mg L⁻¹ to 900 mg L⁻¹and 600 mg L⁻¹to 110 mg L⁻¹, respectively. The most abundant genera were identified as Acetobacter, Achromobacter, Acidaminococcus, Actinomyces, and Acetomicrobium from the textile effluent. This study suggests that an integrated approach of PEO and subsequent biodegradation might be an effective and eco-friendly method for the degradation of textile effluent.

A growing number of studies report associations between air pollution and COVID-19 mortality. Most were ecological studies at the county or regional level which disregard important local variability and relied on data from only the first few months of the pandemic. Using COVID-19 deaths identified from death certificates in California, we evaluated whether long-term ambient air pollution was related to weekly COVID-19 mortality at the census tract-level during the first ∼12 months of the pandemic. Weekly COVID-19 mortality for each census tract was calculated based on geocoded death certificate data. Annual average concentrations of ambient particulate matter <2.5 μm (PM₂.₅) and <10 μm (PM₁₀), nitrogen dioxide (NO₂), and ozone (O₃) over 2014–2019 were assessed for all census tracts using inverse distance-squared weighting based on data from the ambient air quality monitoring system. Negative binomial mixed models related weekly census tract COVID-19 mortality counts to a natural cubic spline for calendar week. We included adjustments for potential confounders (census tract demographic and socioeconomic factors), random effects for census tract and county, and an offset for census tract population. Data were analyzed as two study periods: Spring/Summer (March 16-October 18, 2020) and Winter (October 19, 2020–March 7, 2021). Mean (standard deviation) concentrations were 10.3 (2.1) μg/m³ for PM₂.₅, 25.5 (7.1) μg/m³ for PM₁₀, 11.3 (4.0) ppb for NO₂, and 42.8 (6.9) ppb for O₃. For Spring/Summer, adjusted rate ratios per standard deviation increase were 1.13 (95% confidence interval: 1.09, 1.17) for PM₂.₅, 1.16 (1.11, 1.21) for PM₁₀, 1.06 (1.02, 1.10) for NO₂, and 1.09 (1.04, 1.14) for O₃. Associations were replicated in Winter, although they were attenuated for PM₂.₅ and PM₁₀. Study findings support a relation between long-term ambient air pollution exposure and COVID-19 mortality. Communities with historically high pollution levels might be at higher risk of COVID-19 mortality.

Estuaries are one of the most valuable biomes on earth. Although humans are highly dependent on these ecosystems, anthropogenic activities have impacted estuaries worldwide, altering their ecological functions and ability to provide a variety of important ecosystem services. Many anthropogenic stressors combine to affect the soft sedimentary habitats that dominate estuarine ecosystems. Now, due to climate change, estuaries and other marine areas might be increasingly exposed to the emerging threat of megafires. Here, by sampling estuaries before and after a megafire, we describe impacts of wildfires on estuarine benthic habitats and justify why megafires are a new and concerning threat to coastal ecosystems. We (1) show that wildfires change the fundamental characteristics of estuarine benthic habitat, (2) identify the factors (burnt intensity and proximity to water's edge) that influence the consequences of fires on estuaries, and (3) identify relevant indicators of wildfire impact: metals, nutrients, and pyrogenic carbon. We then discuss how fires can impact estuaries globally, regardless of local variability and differences in catchment. In the first empirical assessment of the impact of wildfires on estuarine condition, our results highlight indicators that may assist waterway managers to empirically detect wildfire impacts in estuaries and identify catchment factors that should be included in fire risk assessments for estuaries. Overall, this study highlights the importance of considering fire threats in current and future estuarine and coastal management.

Polycyclic aromatic hydrocarbons (PAHs) constitute a significant environmental pollution group that reaches toxic levels with anthropogenic activities. The adverse effects of nanoplastics accumulating in ecosystems with the degradation of plastic wastes are also a growing concern. Previous studies have generally focused on the impact of single PAH or plastic fragments exposure on plants. However, it is well recognized that these contaminants co-exist at varying rates in agricultural soil and water resources. Therefore, it is critical to elucidate the phytotoxicity and interaction mechanisms of mixed pollutants. The current study was designed to comparatively investigate the single and combined effects of anthracene (ANT, 100 mg L⁻¹), fluorene (FLU, 100 mg L⁻¹) and polystyrene nanoplastics (PS, 100 mg L⁻¹) contaminations in wheat. Plants exposed to single ANT, FLU and PS treatments demonstrated decline in growth, water content, high stomatal limitations and oxidative damage. The effect of ANT + FLU on these parameters was more detrimental. In addition, ANT and/or FLU treatments significantly suppressed photosynthetic capacity as determined by carbon assimilation rate (A) and chlorophyll a fluorescence transient. The antioxidant system was not fully activated (decreased superoxide dismutase, peroxidase and glutathione reductase) under ANT + FLU, then hydrogen peroxide (H₂O₂) content (by 2.7-fold) and thiobarbituric acid reactive substances (TBARS) (by 2.8-fold) increased. Interestingly, ANT + PS and FLU + PS improved the growth, water relations and gas exchange parameters. The presence of nanoplastics recovered the adverse effects of ANT and FLU on growth by protecting the photosynthetic photochemistry and reducing oxidative stress. PAH plus PS reduced the ANT and FLU accumulation in wheat leaves. In parallel, the increased antioxidant system, regeneration of ascorbate, glutathione and glutathione redox status observed under ANT + PS and FLU + PS. These findings will provide an information about the phytotoxicity mechanisms of mixed pollutants in the environment.

Per- and polyfluorinated alkyl substances (PFAS) are highly persistent chemicals, which pose a potential risk for aquatic wildlife due to their bioaccumulative behaviour and toxicological effects. Although the distribution of PFAS in marine environments has been studied worldwide, little is known on the contamination of PFAS in the southern North Sea. In the present study, the bioaccumulation and trophic transfer of Perfluoroalkyl acids (PFAAs) was studied in liver and muscle tissue of seven fish species and in whole-body tissue of two crustacean species, collected at 10 sites in the Belgian North Sea. Furthermore, the human and ecological health risks were examined. Overall, perfluorooctane sulfonate (PFOS) was predominant in all matrices and other long-chain PFAS were frequently detected. Mean PFOS concentrations ranged from <LOQ to 107 ng/g (ww) in fish liver, from <LOQ to 24 ng/g ww in fish muscle and from 0.29 to 5.6 ng/g ww in crustaceans. Elevated perfluorotridecanoic acid (PFTrDA) concentrations were detected in fish liver from the estuarine and coastal region (<LOQ-116 ng/g ww), indicating a specific point source of this compound. Based on stable isotope analysis, no distinctive trophic transfer patterns of PFAS could be identified which implies that the bioconcentration of PFAS from the surrounding abiotic environment is most likely dominating over the biomagnification in the studied biota. The consumption of commercially important species such as the brown shrimp (Crangon crangon), plaice (Pleuronecta platessa), sole (Solea solea) and whiting (Merlangus merlangus) might pose potential health risks if it exceeds 17 g/day, 18 g/day, 26 g/day and 43 g/day respectively. Most PFOS measurements did not exceed the QSbᵢₒₜₐ,ₕₕ of 9.1 ng/g ww, however, the benchmark of 33 ng/g ww targeting the protection of wildlife from secondary poisoning was exceeded for 43% and 28% of the samples in plaice and sole.

People who relocate to a new environment may experience health effects from a change in ambient air pollution. We undertook a literature review of studies of such relocations and health effects and report the results as a narrative analysis. Fifteen articles of heterogeneous designs met the inclusion criteria. Four short-term (relocation duration less than six months) and three long-term (relocation duration six months or greater) studies reported evidence of the effect of relocation on physiological outcome, biomarkers or symptoms. All had potential weaknesses of design or analysis but, as a whole, their results are broadly consistent in suggesting short-term adverse effects of air pollutants or their reversibility. One long-term study provided evidence that changes in air pollution exposure during adolescence have a measurable effect on lung function growth. Four cohort studies were also identified that used relocation to strengthen evidence of air-pollution-exposure relationships by using a design that incorporates effective randomization of exposure or the use of relocation to improve exposure classification. However, three studies of relocation during pregnancy provided limited evidence to conclude an effect of relocation-related change in exposure on pregnancy outcome. Overall, most relocation studies are consistent with short- or long-term adverse effects of air pollution on biological function or mortality, but many studies of change in exposure have design weaknesses that limit the robustness of interpretation. We outline principles for improved design and analysis to help strengthen future studies for the insights they can provide from their quasi-experimental designs, including on the nature and timing of functional changes of relocation-related changes in exposure to ambient air pollution.

Stable nitrogen isotope (δ¹⁵N) technology has often been used as a powerful tool to separate nitrogen oxides (NOₓ) produced by residential combustion (i.e., biomass burning and coal combustion) from other sources. However, the insufficient measurement of δ¹⁵N-NOₓ fingerprints of these emissions limits its application, especially in North China where residential emissions are significant. This study conducted combustion experiments to determine the δ¹⁵N-NOₓ of typical residential fuels in North China, including ten biomass fuels and five types of coal. The results showed that the δ¹⁵N of biomass varied between −6.9‰ and 2.3‰, which was lower than the δ¹⁵N of residential coal (−0.2‰–4.6‰). After combustion, the δ¹⁵N of biomass residues increased greatly, while that of coal residues showed no significant upward trend (p > 0.05). The δ¹⁵N-NOₓ produced by biomass burning ranged from −5.6‰ to 3.2‰ (−0.4‰ ± 2.4‰), showing a significant linear relation with δ¹⁵N-biomass. Comparatively, the δ¹⁵N-NOₓ derived from residential coal combustion was much higher (16.1‰ ± 3.3‰), ranging from 11.7‰ to 19.7‰. It was not well correlated with δ¹⁵N-coal, and only slightly lower than the estimated δ¹⁵N-NOₓ of industrial coal combustion (17.9‰, p > 0.05). These observations indicate that the δ¹⁵N-NOₓ of residential coal combustion is a result of the mixture of thermal- and fuel-released NOₓ. Based on the isotopic characteristics observed in this study, we analyzed the reported δ¹⁵N-NOₓ, and provided more statistically robust δ¹⁵N-NOₓ distributions for biomass burning (1.3‰ ± 4.3‰; n = 101) and coal combustion (17.9‰ ± 3.1‰; n = 26), which could provide guidance for scientific studies aiming to quantify the origin of NOₓ in North China and in other regions.

Endocrine disrupting chemicals (EDCs) are a matter of great concern. They are ubiquitous in the environment, are considered harmful to humans and wildlife, yet remain challenging to identify based on current international test guidelines and regulatory frameworks. For a compound to be identified as an EDC within the EU regulatory system, a plausible link between an endocrine mode-of-action and an adverse effect outcome in an intact organism must be established. This requires in-depth knowledge about molecular pathways regulating normal development and function in animals and humans in order to elucidate causes for disease. Although our knowledge about the role of the endocrine system in animal development and function is substantial, it remains challenging to predict endocrine-related disease outcomes in intact animals based on non-animal test data. A main reason for this is that our knowledge about mechanism-of-action are still lacking for essential causal components, coupled with the sizeable challenge of mimicking the complex multi-organ endocrine system by methodological reductionism. Herein, we highlight this challenge by drawing examples from male reproductive toxicity, which is an area that has been at the forefront of EDC research since its inception. We discuss the importance of increased focus on characterizing mechanism-of-action for EDC-induced adverse health effects. This is so we can design more robust and reliable testing strategies using non-animal test methods for predictive toxicology; both to improve chemical risk assessment in general, but also to allow for considerable reduction and replacement of animal experiments in chemicals testing of the 21st Century.

Exposure to electronic and electrical waste (e-waste) has been related to a few adverse health effects. In this study, sediment samples from an e-waste recycling town in China were collected, and aryl hydrocarbon receptor (AhR) agonists in the samples were identified using an effect-directed analysis (EDA) strategy. The CBG2.8D cell line reporter gene bioassay was used as a toxicity test, while suspect screening against chemical databases was performed for potential AhR agonist identification where both gas chromatography- and liquid chromatography-high resolution mass spectrometry analyses were run. When the original sample extract showed high AhR-mediated activity, sample fractionation was performed, and fractions exhibiting high bioactivity were chemically analyzed again to reveal the corresponding AhR agonists. In total, 23 AhR agonists were identified, including 14 commonly known ones and 9 new ones. Benzo [k]fluoranthene and 6-nitrochrysene were the dominant AhR agonists, covering 16–71% and 2.7–12%, respectively, of the AhR activation effects measured in the parent extracts. The newly identified AhR-active chemicals combined explained 0.13–0.20% of the parent extracts’ effects, with 7,12-dimethylbenz [a]anthracene and 8,9,11-trimethylbenz [a]anthracene being the major contributors. A diagnostic isomer ratio analysis of polycyclic aromatic hydrocarbons suggested that the major source of AhR agonists identified in these e-waste related sediment samples were probably petroleum product combustion and biomass combustion. In the future, for a more comprehensive AhR agonist investigation, in-house chemical synthesis and purification, and, when necessary, a secondary sample fractionation, would be beneficial.