Organic contaminations and heavy metals in soils cause large harm to human and environment, which could be remedied by planting specific plants. The biochars produced by crop straws could provide substantial benefits as a soil amendment. In the present study, biochars based on wheat, corn, soybean, cotton and eggplant straws were produced. The eggplant straws based biochar (ESBC) represented higher Cd and pyrene adsorption capacity than others, which was probably owing to the higher specific surface area and total pore volume, more functional groups and excellent crystallization. And then, ESBC amendment hybrid Ryegrass (Lolium perenne L.) cultivation were investigated to remediate the Cd and pyrene co−contaminated soil. With the leaching amount of 100% (v/w, mL water/g soil) and Cd content of 16.8 mg/kg soil, dosing 3% ESBC (wt%, biochar/soil) could keep 96.2% of the Cd in the 10 cm depth soil layer where the ryegrass root could reach, and it positively help root adsorb contaminations. Compared with the single planting ryegrass, the Cd and pyrene removal efficiencies significantly increased to 22.8% and 76.9% by dosing 3% ESBC, which was mainly related with the increased plant germination of 80% and biomass of 1.29 g after 70 days culture. When the ESBC dosage increased to 5%, more free radicals were injected and the ryegrass germination and biomass decreased to 65% and 0.986 g. Furthermore, when the ESBC was added into the ryegrass culture soil, the proportion of Cd and pyrene degrading bacteria Pseudomonas and Enterobacter significantly increased to 4.46% and 3.85%, which promoted the co−contaminations removal. It is suggested that biochar amendment hybrid ryegrass cultivation would be an effective method to remediate the Cd and pyrene co−contaminated soil.

After the exploitation of coal mines in the 19th and 20th centuries in northern France, many mining slag heaps (SH) were left without any particular management or monitoring. Currently, the influence of these SHs on the quality of surrounding wetlands is hardly known.The purpose of this work is to determine the water quality in the neighbourhood of two SHs located near the city of Douai and its influence on the distribution of aquatic invertebrates in local wetlands. Our approach involves (1) the spatial and temporal characterization of the water composition (anions, major elements, sulphide, DOC and alkalinity) and of the biological diversity (aquatic invertebrates) and (2), based on this chemical and biological screening, the establishment of relationships between water quality and biodiversity distribution through multivariate data analysis. The results clearly indicate that substantial leaching from the slag heaps occurs, given the very high concentrations of dissolved sulphates (in the range of 2 g L⁻¹). While the pH remains weakly basic, indicating that the leaching water has been neutralized by the highly carbonated regional substratum, high levels of biodegradable organic matter and sulphate contents have been noticed. They sporadically cause significant drops in dissolved oxygen and the occurrence of dissolved sulphides that massively reduce biodiversity, qualitatively and quantitatively. In Summer, oxygen saturation is generally lower due to the higher rate of organic matter degradation, and the risk of anoxic episodes therefore increases. Finally, as wetlands are vulnerable environments, these preliminary results suggest that monitoring and management of these sites must be attempted quickly to avoid the degradation of those valuable habitats.

Natural and synthetic steroid hormones and many persistent organic pollutants are of concern for their endocrine-disrupting activities observed in receiving surface waters. Apart from the demonstrated presence of estrogen- and estrogen-mimicking compounds in surface waters, antagonistic (anti-estrogenic) responses originating from wastewater effluent have been reported but are less known. Estrogenicity and anti-estrogenicity were assessed using recombinant yeast estrogen receptor binding assays (YES/YAES) at ten South African wastewater treatment works (WWTWs) and receiving rivers in two separate sampling campaigns during the summer- and winter periods in the area. Four WWTWs were then further investigated to show daily variation in estrogenic endocrine-disrupting activities during the treatment process. Although estrogenicity was notably reduced at most of the WWTWs, some treated effluent and river water samples were shown to be above effect-based trigger values posing an endocrine-disrupting risk for aquatic life and potential health risks for humans. Furthermore, estrogenicity recorded in samples collected upstream from some WWTW discharge points also exceeded some calculated risk trigger values, which highlights the impact of alternative pollution sources contributing towards endocrine disrupting contaminants (EDCs) in the environment. The YAES further showed variable anti-estrogenic activities in treated wastewater. The current study highlights a variety of factors that may affect bioassay outcomes and conclusions drawn from the results for risk decision-making. For example, mismatches were found between estrogenic and anti-estrogenic activity, which suggests a potential masking effect in WWTW effluents and highlights the complexity of environmental samples containing chemical mixtures having variable endocrine-disrupting modes of action. Although the recombinant yeast assay is not without its limitations to show endocrine-disrupting modulation in test water systems, it serves as a cost-effective tier-1 scoping assay for further risk characterisation and intervention.

Urban vegetation is associated with numerous public health benefits; however, urban tree canopies may be threatened by fugitive methane exposure from leaky natural gas distribution systems. Despite anecdotal evidence of the harmful impacts of natural gas leaks on urban tree decline, the relationship between soil gas exposure and tree health has not been formally quantified in an urban setting. We conducted a case-control study to compare soil natural gas exposure in sidewalk tree pits of healthy and dead or dying trees in Chelsea, Massachusetts, during summer 2019. We measured soil concentrations of methane and oxygen at four points around the trunks of 84 case and 97 control trees. We determined that case trees had 30 times the odds of being exposed to detectable levels of soil methane relative to the control trees sampled (95% CI = 3.93, 229). Among tree pits with elevated soil gas, we also found that methane concentrations were highest on the side of the tree pit closest to the street. These results contribute evidence to support the widespread belief that soil methane exposure can negatively impact urban tree health. They also suggest that fugitive methane leakage from urban natural gas distribution systems beneath the street surface may be responsible for elevated soil gas concentrations in sidewalk tree pits and subsequent tree death.

Organophosphate esters (OPEs) are high-production volume chemicals. Use of OPEs has largely increased since the phase-out/ban of polybrominated diphenyl ethers (PBDEs). The ubiquitous occurrence of OPEs, in higher concentrations in abiotic matrices than brominated flame retardants (BFRs), is a concern because several of the OPEs have been linked to adverse health effects. In this study, urinary metabolites of OPEs were measured in a subset of a population-based sample of women of child bearing age recruited in Ontario, and associations between serum lipid levels and urinary concentrations of OPE metabolites were evaluated. Urine samples (n = 120) were extracted using automated solid phase extraction and analysed by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Diphenyl phosphate (DPHP), bis(2-chloropropyl) phosphate (BCIPP) and bis(1,3-dichloro-2 propyl) phosphate (BDCIPP) were detected with frequencies of 100%, 76% and 75% at median concentrations of 13.8 ng/mL, 0.5 ng/mL and 1.8 ng/mL, respectively. Bis(2-chloroethyl) hydrogen phosphate (BCEP) and di-cresyl phosphate (DCP; mixture of 3 isomers) were detected in 52% and 42% of the samples, respectively. Detected at lower frequencies were 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP, 29%), bis-2(butoxyethyl) phosphate (BBOEP, 11%), and desbutyl-tris-(2-butoxy-ethyl) phosphate (desbutyl TBOEP, 9%). Using multiple regression model, a negative statistically significant correlation was observed between BCEP and cholesterol (p = 0.04), as well as BCEP and total lipid (p = 0.04). Whereas BCIPP was positively and significantly correlated with cholesterol (p = 0.003) and LDL (p = 0.001). Additional work to further explore these relationships and to evaluate more recently identified OPE metabolites is warranted.

This work aims to study the pseudo-total content, geochemical fractions, and species of arsenic (As) in the bulk soil and in the coarse and fine particles of top soil and soil profiles collected from active and abandoned gold mine spoils in Ghana. The human health risk for adults (male and female) and children has been assessed. To achieve our aims, we collected 51 samples, characterized them, determined the total As content, and sequentially extracted the geochemical fractions of As including water-soluble and un-specifically bound As (FI); specific-sorbed/exchangeable As (FII); poorly (FIII)- and well-crystalline (IV) Fe oxide; and residual/sulphide fraction (FV). In selected samples, As species were determined using synchrotron-based X-ray absorption near edge structure (XANES). Pseudo-total As contents varied from 1807 to 8400 mg kg⁻¹, with the extremes occurring at the abandoned mine spoil. Arsenic was almost 10-fold higher in the fine particles (<0.63 μm) than in the coarse particles. Arsenic was mainly associated with FIII and FV, indicating that the distribution of As in these spoils is governed by their contents of amorphous Fe oxides, sulphides and As bearing minerals. The XANES results indicated that scorodite (FeAsSO₄ = 65–76%) and arsenopyrite (FeAsS = 24–35%) are the two major As-containing minerals in the spoils. The potential mobility (PMF = ∑FI-FIV) of As in the fine particles of the top soil was higher (48–61%) than in the coarse particles (25–44%). The mobile fraction (MF) (FI+FII) and PMF of As in the coarse particles of the profiles increased with depth while it decreased in the fine particles. The median hazard index values indicated an elevated human health risk, especially for children. The high contamination degree and potential mobility of As at the studied mine spoils indicate high potential risk for human and environmental health.

Arsenic exposure contributed to the development of human diseases. Arsenic exerted multiple organ toxicities mainly by triggering oxidative stress. However, the signaling pathway underlying oxidative stress is unclear. We previously found that the expression of SFPQ, a splicing factor, was positively associated with urinary arsenic concentration in an arsenic-exposed population, suggesting an oxidative stress regulatory role for SFPQ. To test this hypothesis, we established cell models of oxidative stress in human hepatocyte cells (L02) treated with NaAsO₂. Reactive oxygen species (ROS) synthesis displayed a time- and dose-dependent increase with NaAsO₂ treatment. SFPQ suppression resulted in a 36%–53% decrease in ROS generation, leading to enhanced cellular damage determined by 8-OHdG, comet tail moment, and micronucleus analysis. Particularly, SFPQ deficiency attenuated expression of the oxidase genes DUOX1, DUOX2, NCF2, and NOX2. A fluorescent-based RNA electrophoretic mobility shift assay (FREMSA) and dual-luciferase reporter system revealed that miR-92b-5p targeted DUOX2 mRNA degradation. An RNA immunoprecipitation assay showed an interaction between SFPQ and miR-92b-5p of the miRNA-induced silencing complex (miRISC). Notably, NaAsO₂ treatment diminished the interaction between SFPQ and miR92b-5p, accompanied by decreased binding between miR-92b-5p and 3′-UTR of DUOX2. However, SFPQ deficiency suppressed the dissociation of miR-92b-5p from 3′-UTR of DUOX2, indicating that miR-92b-5p regulated the SFPQ-dependent DUOX2 expression. Taken together, we reveal that SFPQ responds to arsenic-induced oxidative stress by interacting with the miRISC. These findings offer new insight into the potential role of SFPQ in regulating cellular stress response.

Cadmium (Cd), which is a toxic non-essential heavy metal capable of entering plants and thus the food chain, constitutes a major environmental and health concern worldwide. An understanding of the tools used by plants to overcome Cd stress could lead to the production of food crops with lower Cd uptake capacity and of plants with greater Cd uptake potential for phytoremediation purposes in order to restore soil efficiency in self-sustaining ecosystems. The signalling molecule nitric oxide (NO), whose function remains unclear, has recently been involved in responses to Cd stress. Using different mutants, such as nia1nia2, nox1, argh1-1 and Atnoa1, which were altered in NO metabolism, we analysed various parameters related to reactive oxygen and nitrogen species (ROS/RNS) metabolism and seedling fitness following germination and growth under Cd treatment conditions for seven days. Seedling roots were the most affected, with an increase in ROS and RNS observed in wild type (WT) seedling roots, leading to increased oxidative damage and fitness loss. Mutants that showed lower NO levels in seedling roots under Cd stress were more resistant than WT seedlings due to the maintenance of antioxidant systems which protect against oxidative damage.

Nitrogen (N) plays an important role in agriculture crop production but the increasing application of nitrogen increases the possibilities of groundwater contamination through nitrate leaching. Nitrate leaching is the inevitable part of agriculture production which occurs during nitrogen fertilization. Hence, the quantification of nitrogen fertilizer is required to reduce nitrate leaching. In this study, nitrogen transformation and transport such as ammonium (NH₄⁺) and nitrate (NO3−) at different soil depths and maize crop growth stages were measured during field experiments for two sowing dates (timely and delay) and four N fertilization levels under irrigated (year 2013 and 2014) and rainfed (year 2012 and 2014) conditions for maize crop. NH₄⁺, NO3− and total nitrogen concentrations were measured using spectrophotometer at 410 nm and Kjeldahl method at varying soil depths and maize crop growth stages. Thereafter, nitrogen balance approach was used to estimate the NO3− leaching. Results indicated that NO3− leaching in irrigated condition was higher 109% in N₇₅, 179% in N₁₀₀, and 292% in N₁₂₅ level respectively in comparison to the N₀ level in timely sowing date, while in delayed sowing date, leaching was higher 54% in N₇₅, 123% in N₁₀₀, and 184% in N₁₂₅ level respectively in comparison to N₀ level. In rainfed, the NO3− leaching was higher 30% in N₆₀, 59% in N₈₀, and 99% in N₁₀₀ level respectively in comparison to N₀ level for the timely sowing date, while in delayed sowing, leaching was higher 23% in N₆₀, 44% in N₈₀, and 78% in N₁₀₀ level respectively in comparison to N₀ level. The results indicate that leaching losses were less in timely sowing dates for both rainfed and irrigated maize. The study further reveals that sowing dates combination with N levels could be an effective management strategy to reduce NO3− leaching by minimizing the N fertilization.

Interactions between the intestine and the liver, the so-called ‘gut-liver axis’, play a crucial role in the onset of hepatic steatosis and non-alcoholic fatty liver disease. However, not much is known about the impact of environmental pollutants on the gut-liver axis and consequent hepatic steatosis. Bisphenol A (BPA), a widely used plasticiser, is an important environmental contaminant that affects gut microbiota. We hypothesised that BPA induces hepatic steatosis by promoting gut microbiota dysbiosis and activating the gut-liver axis. In this study, male CD-1 mice were fed with diet containing BPA (50 μg/kg body weight/day) for 24 weeks. Dietary exposure to BPA increased lipid contents and fat accumulation in the liver. Analysis of 16 S rRNA gene sequencing revealed that the diversity of gut microbiota reduced and the composition of gut microbiota was altered in the BPA-fed mice. Further, the abundance of Proteobacteria, a marker of dysbacteria, increased, whereas the abundance of Akkermansia, a gut microbe associated with increased gut barrier function and reduced inflammation, markedly decreased. Expression levels of intestinal tight junction proteins (zona occludens-1 and occludin) also decreased drastically, leading to increased intestinal permeability and elevated levels of endotoxins. Furthermore, BPA up-regulated the expression of Toll-like receptor 4 (TLR4) and phosphorylation of nuclear factor-kappa B (NF-κB) in the liver and increased the production of inflammatory cytokines, including interleukin-1β, interleukin-18, tumour necrosis factor-α, and interleukin-6. Take together, our work indicated that dietary intake of BPA induced hepatic steatosis, and this was closely related to dysbiosis of gut microbiota, elevated endotoxin levels, and increased liver inflammation through the TLR4/NF-κB pathway.