Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation and cytokinesis. Taking into account the results we previously obtained on the same genitors, this study showed a negative effect of diuron on oyster reproduction by inducing both structural and functional modifications of the DNA.

An analytical method associating accelerated solvent extraction (ASE) and solid-phase micro-extraction (SPME) in immersion mode combined with gas chromatography dual electrons capture detectors (SPME-GC-2ECD) has been developed and studied for the simultaneous determination of 19 organochlorine pesticides (OCPs) and 22 polychlorinated biphenyls (PCBs) in air samples (active and XAD-2 passive samplers). Samples were extracted with ASE with acetonitrile using the following conditions: temperature, 150 °C; pressure, 1500 psi; static, 15 min; cycles, 3; purge, 300 s; flush, 100 %. Extracts were reduced to 1 mL, and 500 μL of this extract, filled with deionised water, was subject to SPME extraction. Experimental results indicated that the proposed method attained the best extraction efficiency under the optimised conditions: extraction of PCB-OCP mixture using 100-μm PDMS fibre at 80 °C for 40 min with no addition of salt. The performance of the proposed ASE-SPME-GC-2ECD methodology with respect to linearity, limit of quantification and detection was evaluated by spiking of XAD-2 resin with target compounds. The regression coefficient (R ²) of most compounds was found to be high of 0.99. limits of detection (LODs) are between 0.02 and 4.90 ng m⁻³, and limits of quantification (LOQs) are between 0.05 and 9.12 ng m⁻³ and between 0.2 and 49 ng/sampler and 0.52 and 91 ng/sampler, respectively, for XAD-2 passive samplers. Finally, a developed procedure was applied to determine selected PCBs and OCPs in the atmosphere.

Shengjin Lake is an important wintering and stopover habitat for migratory birds en route from East Asia to Australia. The authors investigated the rotifer community structure and environmental factors in upper Shengjin Lake from February to July of 2014. A total of 17 genera and 31 species of rotifers were identified, the dominant species being Brachionus angularis, Brachionus calyciflorus, Asplanchna priodonta, and Schizocerca diversicornis. Rotifer density and the nutrient salt content were higher in the areas inhabited by migratory birds. The highest density (176.0 ind./L) was recorded in June, the lowest (14.0 ind./L) in April. Canonical correspondence analysis (CCA) and correlation analysis showed that some environmental factors, such as temperature, pH, water depth, Secchi depth (SD), and chlorophyll a concentration, had a considerable effect on the lake’s rotifer community structure.

Children especially infants are particularly sensitive to contaminant exposure, they are exposed to toxic substances including heavy metals via multiple pathways, i.e. food, air, water, soil and childcare products. To date, determination of metal bioaccessibility in teethers and feeding teats is missing in the literature; therefore, it is vitally important to assess their metal bioaccessibility and characterise the risk for children. The aim of this study is to determine the migration levels of toxic elements in teethers and feeding teats of different brands as a measure of metal bioaccessibility and characterise the risk for children exposed to these products. The migration limits of several heavy metals (Al, As, Ba, Cd, Co, Cu, Cr, Mn, Ni, Pb, Se, Sr, Zn) in different brands of teethers and feeding teats were determined simultaneously using inductively coupled plasma optical emission spectroscopy (ICP-OES) adopting a protocol in the European standards for safety of toys. With the exception of Pb, the migration limits of all elements in all brands of teethers and feeding teats were below the specified limits. However, in the case of Pb, the migration was above the specified limits in all samples except one brand of feeding teats. Risk assessment expressed as hazard index (HI) was calculated for detected elements and all samples. Although HI was below 1.0 for all samples except one sample, the high Pb concentration would pose a considerable risk to children. Therefore, we recommend a more thorough research and risk characterisation taking into consideration the factors that affect HI values.

The widely used solvent extractant, tributyl phosphate (TBP), primarily used as a solvent for the conventional processing of nuclear fuel, has come under scrutiny recently due to concerns surrounding potential environmental contamination and toxicity. In this study, we found that, in Phaeodactylum tricornutum, administration of TBP severely inhibited algal cell growth by reducing photosynthetic efficiency and inducing oxidative stress. We further explored the effect of TBP by examining the gene expression of the photosynthetic electron transport chain and its contribution to reactive oxygen species (ROS) burst. Our data revealed that TBP affected both fatty acid content and profile by regulating the transcription of genes related to glycolysis, fatty acid biosynthesis, and β-oxidation. These results demonstrated that TBP did in fact trigger the synthesis of ROS, disrupting the subcellular membrane structure of this aquatic organism. Our study brings new insight into the fundamental mechanism of toxicity exerted by TBP on the marine alga P. tricornutum.

Cadmium nanoparticles can represent a risk in both industrial and environmental settings, but there is little knowledge on the impacts of their inhalation, especially concerning longer-term exposures. In this study, mice were exposed to cadmium oxide (CdO) nanoparticles in whole body inhalation chambers for 4 to 72 h in acute and 1 to 13 weeks (24 h/day, 7 days/week) in chronic exposure to investigate the dynamics of nanoparticle uptake and effects. In the acute experiment, mice were exposed to 2.95 × 10⁶ particles/cm³ (31.7 μg CdO/m³). The same concentration and a lower one (1.18 × 10⁶ particles/cm³, 12.7 μg CdO/m³) were used for the chronic exposure. Transmission electron microscopy documented distribution of nanoparticles into all studied organs. Major portion of nanoparticles was retained in the lung, but longer exposure led to a greater relative redistribution into secondary organs, namely the kidney, and also the liver and spleen. Accumulation of Cd in the lung and liver occurred already after 24 h and in the brain, kidney, and spleen after 72 h of exposure, and a further increase of Cd levels was observed throughout the chronic exposure. There were significant differences in both Cd accumulation and effects between the two exposure doses. Lung weight in the higher exposure group increased up to 2-fold compared to the control. Histological analyses showed dose-dependent alterations in lung and liver morphology and damage to their tissue. Modulation of oxidative stress parameters including glutathione levels and increased lipid peroxidation occurred mainly after the greater chronic exposure. The results emphasize risk of longer-term inhalation of cadmium nanoparticles, since adverse effects occurring after shorter exposures gradually progressed with a longer exposure duration.

Heavy metals in urban soils may pose risks to both urban environment and human health. However, only a fraction of heavy metals in soil is mobile and/or bioavailable for plant uptake and human ingestion. This study evaluates the chemical fraction and potential mobility and bioaccessibility of heavy metals (Cd, Cr, Cu, Pb, and Zn) in the contaminated urban topsoils from steel-industrial city (Anshan), Northeastern China. Chemical forms of heavy metals in soils are determined using Tessier sequential extraction technique. The toxicity characteristic leaching procedure (TCLP), ethylenediaminetetraacetic acid (EDTA), and US Pharmacopeia methodology (USPM) are used to determine the operationally defined potentially mobile and bioaccessible metal fractions, respectively. Sequential extraction results show that Cd has the highest percentage of exchangeable form, whereas Cr primarily exists in residual form. The non-residual fraction of heavy metals increases in the order of Cr < Cu < Pb < Zn < Cd. The leachability of heavy metals evaluated by TCLP test indicates that Cd, Zn, Cu, and Pb have much higher mobile than Cr. The bioavailability of heavy metals determined by EDTA extraction decreases in the order of Pb > Cu ≅ Zn > Cd > Cr. The order of bioaccessibility determined by USPM extraction is Pb = Cu > Zn > Cd > Cr. The Cr exhibits the lowest leachability and bioaccessibility among the investigated metals. The Pb has the highest bioaccessibility, indicating higher potential hazard for the human health. There are significant relationships between the EDTA- and USPM-extractable metals (Cd, Cu, Pb, and Zn) and the sum of first three steps of sequential extraction. Highly significant correlation is found between amounts of EDTA-extractable Cd, Cu, Pb, and Zn and USPM-extractable metals. The result suggests that EDTA extraction can be helpful to estimate the bioaccessibility of heavy metals for human ingestion. Introduction of mobile and human bioaccessible concentrations into risk assessments can give more realistic implications for urban environmental management.

Selective catalytic reduction of NO X by hydrogen (H₂-SCR) in the presence of oxygen has been investigated over the NiCo₂O₄ and Pd-doped NiCo₂O₄ catalysts under varying conditions. The catalysts were prepared by a sol-gel method in the presence of oxygen within 50–350 °C and were characterized using XRD, BET, EDS, XPS, Raman, H₂-TPR, and NH₃-TPD analysis. The results demonstrated that the doped Pd could improve the catalyst reducibility and change the surface acidity and redox properties, resulting in a higher catalytic performance. The performance of NiCo₁.₉₅Pd₀.₀₅O₄ was consistently better than that of NiCo₂O₄ within the 150–350 °C range at a gas hourly space velocity (GHSV) of 4800 mL g⁻¹ h⁻¹, with a feed stream containing 1070 ppm NO, 10,700 ppm H₂, 2 % O₂, and N₂ as balance gas. The effects of GHSV, NO/H₂ ratios, and O₂ feed concentration on the NO conversion over the NiCo₂O₄ and NiCo₁.₉₅Pd₀.₀₅O₄ catalysts were also investigated. The two samples similarly showed that an increase in GHSV from 4800 to 9600 mL h⁻¹ g⁻¹, the NO/H₂ ratio from 1:10 to 1:1, and the O₂ content from 0 to 6 % would result in a decrease in NO conversion. In addition, 2 %, 5 %, and 8 % H₂O into the feed gas had a slightly negative influence on SCR activity over the two catalysts. The effect of SO₂ on the SCR activity indicated that the NiCo₁.₉₅Pd₀.₀₅O₄ possesses better SO₂ tolerance than NiCo₂O₄ catalyst does. Graphical abstract The NiCo₁.₉₅Pd₀.₀₅O₄ catalyst achieved over 90 % NO conversion with N₂ selectivity of 100 % in the 200∼250 °C range than the maximum 40.5 % NO conversion over NiCo₂O₄ with N₂ selectivity of approximately 80 % in 350 °C.

Acetaminophen (ACT) is one of the most frequently detected pharmaceuticals in aqueous environments, and treatment of ACT were generally carried out by photocatalytic degradations under high energy UV irradiation. In this study, potassium ferricyanide was utilized as a quadruple-elemental dopant in a TiO₂ photocatalyst in order to enhance its visible-light activity. Two critical parameters (amounts of dopants and durations of calcination) of the synthesis of the photocatalyst by a sol–gel method were systematically evaluated. Crystal structure of the doping TiO₂ was examined by X-ray diffraction while the effects of the two parameters on the photocatalytic activity were elucidated by various characterizations. Increasing the amount of dopant or the duration of calcination red-shifted the UV–vis DRS of the doped TiO₂. The estimated band gap energy of the doped TiO₂ decreased slightly as the amount of dopant increased, but it increased as the duration of calcination increased. The FT-IR yielded characteristic peaks that revealed the effects of the two parameters, whereas the SEM images revealed the morphological evolutions of each effect. The photocatalyst, synthesized at optimum conditions was able to remove 99.1 % acetaminophen with rate constant of 7.9 × 10⁻³ min⁻¹, which was 4.88 times greater than virgin TiO₂. In general, this study not only optimized synthetic conditions of the new visible-light active photocatalyst for ACT degradation but also presented characterizations conducted by SEM, XRD, UV–vis DRS, and FTIR to elucidate the relationship between modified structure and the photocatalytic activity. Graphical abstract Effects of doping amounts of K₃[Fe(CN)₆] and calcunation duration on visible light absorbance of TiO₂ photocatalysts

Hydrogen production by methane dry reforming is an important yet challenging process. A performing catalyst will favor the thermodynamic equilibrium while ensuring good hydrogen selectivity. We hereby report the synthesis of Co ₓ Mg₆₋ₓ Al₂ (with x = 2 and 6) mixed oxide catalysts synthesized via hydrotalcite precursors and the synthesis of a ruthenium-based catalyst on a cobalt, magnesium, and aluminum mixed oxide supports Ru/Co ₓ Mg₆₋ₓ Al₂ (with x = 2 and 6). The impregnation of ruthenium on the hydrotalcites was performed in two ways: by impregnation on the dried hydrotalcite and by memory effect on hydrotalcite calcined at 500 °C. The deposition of ruthenium by memory effect of the magnesium and cobalt support allows the generation of both metallic and basic sites which provides an active and stable catalyst for the dry reforming reaction of methane.