Natural media such as soil and sediment contain mineralogical and organic components with distinct chemical, surface, and electrostatic properties. To better understand the role of various soil and sediment components on particle transport, columns were packed with quartz sand and natural sediment with added Fe oxyhydroxide coating, illite clay, and peat moss to investigate how these added components influence nTiO₂ retention and transport in geochemically heterogeneous medium. Results showed that nTiO₂ transport was low at pH 5, attributable to the electrostatic attraction between positively-charged nTiO₂ and negatively-charged medium. While illite did not notably affect nTiO₂ transport at pH 5, Fe oxyhydroxide coating increased nTiO₂ transport due to electrostatic repulsion between Fe oxyhydroxide and nTiO₂. Peat moss also increased nTiO₂ transport at pH 5, attributable to the increased DOC concentration, which resulted in higher DOC adsorption to nTiO₂ and intensified electrostatic repulsion between nTiO₂ and the medium. At pH 9, nTiO₂ transport was high due to the electrostatic repulsion between negatively-charged nTiO₂ and medium surfaces. Fe oxyhydroxide coating at pH 9 slightly delayed nTiO₂ transport due to electrostatic attraction, while illite clay and peat moss substantially inhibited nTiO₂ transport via straining/entrapment or electrostatic attraction. Overall, this study demonstrated that pH has a considerable effect on how minerals and organic components of a medium influence nTiO₂ transport. At low pH, electrostatic attraction was the dominant mechanism, therefore, nTiO₂ mobility was low regardless of the differences in mineralogical and organic components. Conversely, nTiO₂ mobility was high at high pH and nTiO₂ retention was dominated by straining/entrapment and sensitive to the mineralogical and organic composition of the medium.

Deltamethrin (DLM) is an important member of the pyrethroid pesticide family, and its widespread use has led to serious environmental and health problems. Exposure to DLM causes pathological changes in the liver of animals and humans and can lead to liver fibrosis. However, the mechanism of DLM-induced liver fibrosis remains unclear. Therefore, to address its potential molecular mechanisms, we used both in vivo and in vitro methods. Quails were treated in vivo by intragastric administration of different concentrations of DLM (0, 15, 30, or 45 mg kg⁻¹), and the chicken liver cancer cell line LMH was treated in vitro with various doses of DLM (0, 50, 200, or 800 μg mL⁻¹). We found that DLM treatment in vivo induced liver fibrosis in a dose-dependent manner through the promotion of oxidative stress, activation of transforming growth factor-β1 (TGF-β1) and phosphorylation of Smad2/3. Treatment of LMH cells with different concentrations of DLM similarly induced oxidative stress and also decreased cell viability. Collectively, our study demonstrates that DLM-induced liver fibrosis in quails occurs via activation of the TGF-β1/Smad signaling pathway.

A large amount of plastic waste has been discharged into the environment worldwide, which causes the current white pollution problem. The accumulated waste plastics in the environment can be furtherly degraded into small pieces such microplastics and nanoplastics through weathering, which will do more harm to the environment and humans than large plastics. Therefore, plastic production and disposal are needed to be considered. Biodegradable plastics (BPs) have become the focus of recent research due to their potential biodegradability and harmlessness, which would be the most effective approach to manage the issue of plastic waste environmental accumulation. However, in the long run, it is uncertain whether BPs can be a promising solution to waste disposal and global plastic pollution. Consequently, both sides of the dispute are discussed in this paper. At present, most conventional plastics can not be replaced by theses BPs. Biodegradation of BPs needs certain environmental conditions, which are not always reliable in the environment. Additionally, changes in human behavioral awareness will also affect the development and application of BPs. BPs should not be considered as a technical solution, thus excusing our environmental responsibility, because littering does not change with the promotion of an effective technology. As such, the conclusion is that BPs may be a part of the solution. The effectiveness in providing environmentally solutions for plastic waste management depends on the combination of affordable waste classification technologies and investment in organic waste treatment facilities. Therefore, there is still a long way to go to solve the global plastic pollution through BPs.

The potential risks of phthalates affecting human and animal health as well as the environment are emerging as serious concerns worldwide. However, the mechanism by which phthalates induce developmental effects is under debate. Herein, we found that embryonic exposure of zebrafish to di-(2-ethylhexyl) phthalate (DEHP) and di-butyl phthalate (DBP) increased the rate of heart defects including abnormal heart rate and pericardial edema. Changes in the transcriptional profile demonstrated that genes involved in the development of the heart, such as tbx5b, nppa, ctnt, my17, cmlc1, were significantly altered by DEHP and DBP at 50 μg/L, which agreed with the abnormal cardiac outcomes. Methylated DNA immunoprecipitation sequencing (MeDIP-Seq) further showed that significant hypomethylation of nppa and ctnt was identified after DEHP and DBP exposure, which was consistent with the up-regulation of these genes. Notably, hypermethylation on the promoter region (<1 kb) of tbx5b was found after DEHP and DBP exposure, which might be responsible for its decrease in transcription. In conclusion, phthalates have the potential to induce cardiac birth defects, which might be associated with the transcriptional regulation of the involved developmental factors such as tbx5b. These findings would contribute to understand the molecular pathways that mediated the cardiac defects caused by phthalates.

Trace elements (TEs) in the insoluble particles of surface snow are less affected by melting processes and can be used as environmental proxies to reveal natural and anthropogenic emissions. Here the first comprehensive study of the 16 TEs (Al, As, Ba, Bi, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Sr, Ti, U, V, and Zn) in insoluble particles (>0.45 μm) from surface snow samples collected at Urumqi Glacier No. 1 (UG1), Eastern Tien Shan, China, from February 2008 to January 2010 were presented. Results show that concentrations of most insoluble particulate TEs (TEs ᵢₙₛₒₗ) in the snow were higher in summer while lower in winter, due to the increasing particle inputs and melting processes. The abundances of As, Cr, Cu, Ni, Pb, and Zn in some samples were higher than those in surrounding urban soils, which might due to these TEs have further anthropogenic input beyond the already contaminated re-suspended urban soil particles and TEs were mainly enriched in particles with small grain size. Based on enrichment factor (EF) and principal component analysis (PCA), our results suggest that eight TEs (Al, Fe, Ti, Ba, Mn, Sr, U, and V) mainly came from mineral dust, while the remaining eight TEs (As, Bi, Cr, Cu, Ni, Pb, Sn, and Zn) were affected by coal combustion, mining and smelting of non-ferrous metals, traffic emissions, and the steel industry. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggests that pollutants might originate from Xinjiang province, Kazakhstan, and Kyrgyzstan. Moreover, UG1 received more significant inputs of particle-bound pollutants in summer than in winter due to the stronger convection and the prevailing valley wind that transports pollutants from the city of Urumqi.

Perfluoroalkyl substances (PFASs) are a class of organohalogenated compounds of environmental concern due to similar characteristics as the well-studied legacy persistent organic pollutants (POPs) that typically show environmental persistence, biomagnification and toxicity. Nevertheless, PFAS are still poorly regulated internationally and in many aspects poorly understood. Here, we studied liver and muscle concentrations in five cetacean species stranded at the southeastern coast of Spain during 2009–2018. Twelve of the fifteen targeted compounds were detected in >50% of the liver samples. Hepatic concentrations were significantly higher than those in muscle reflecting the particular toxicokinetics of these compounds. Bottlenose dolphins Tursiops truncatus showed the highest hepatic ΣPFAS (n = 5; 796.8 ± 709.0 ng g⁻¹ ww) concentrations, followed by striped dolphin Stenella coeruleoalba (n = 29; 259.5 ± 136.2 ng g⁻¹ ww), sperm whale Physeter macrocephalus (n = 1; 252.8 ng g⁻¹ ww), short-beaked common dolphin Delphinus delphis (n = 2; 240.3 ± 218.6 ng g⁻¹ ww) and Risso’s dolphin Grampus griseus (n = 1; 78.7 ng g⁻¹ ww). These interspecies differences could be partially explained by habitat preferences, although they could generally not be related to trophic position or food chain proxied by stable N (δ¹⁵N) and C (δ¹³C) isotope values, respectively. PFAS profiles in all species showed a similar pattern of concentration prevalence in the order PFOS>PFOSA>PFNA≈PFFUnA>PFDA. The higher number of samples available for striped dolphin allowed for evaluating their PFAS burden and profile in relation to the stranding year, stable isotope values, and biological variables including sex and length. However, we could only find links between δ¹⁵N and PFAS burdens in muscle tissue, and between stranding year and PFAS profile composition. Despite reductions in the manufacturing industry, these compounds still appear in high concentrations compared to more than two decades ago in the Mediterranean Sea and PFOS remains the dominating compound.

In recent years, excessive application and loss of pesticides have caused great risks to the aquatic systems, but the spatio-temporal variability in the ecological risk that agricultural pesticides pose to aquatic systems has not been explored at the national scale. In this study, an integrated assessment framework was proposed for the potential ecological risk of surface water caused by agricultural pesticide loss. The spatio-temporal variability in the potential ecological risk caused by agricultural pesticide runoff was evaluated. Based on the results, the total pesticide emissions increased from 165.47 tons in 2004 to 179.77 tons in 2017. Among the three pesticide types, insecticide had the largest application, but its runoff was estimated as the lowest. High-risk areas of insecticide runoff were concentrated in the east, south and central part of China, while the central region of China was identified as a hotspot due to the high and the ever-increasing ecological risk. This study provides an integrated method for potential ecological risk assessment of agricultural pesticide runoff to adjacent water bodies in large-scale regions and the results of the study have direct implications for environmental policies on pesticide management in China and around the world.

The non-magnetic capping materials are difficult to be recycled from the water bodies after their application, leading to the increase in the cost of the sediment remediation. To address this issue, a capping material, i.e., magnetic lanthanum/iron-modified bentonite (M-LaFeBT) was prepared by loading lanthanum onto a magnetic iron-modified bentonite (M-FeBT) and used to control the internal phosphorus (P) loading in this study. To determine the capping efficiency and mechanism of M-LaFeBT, the impact of M-LaFeBT and M-FeBT capping on the mobilization of P in sediments was investigated, and the stabilization of P bound by the M-LaFeBT and M-FeBT capping layers was evaluated. Results showed that M-LaFeBT possessed good magnetic property with a saturated magnetization of 14.9 emu/g, and exhibited good phosphate adsorption ability with a maximum monolayer sorption capacity (QMAX) of 14.3 mg P/g at pH 7. Moreover, M-LaFeBT capping tremendously reduced the concentration of soluble reactive P (SR-P) in the overlying water (OL-water), and the reduction efficiencies were 94.7%–97.4%. Furthermore, M-LaFeBT capping significantly decreased the concentration of SR-P in the pore water and DGT (diffusive gradient in thin films)-labile P in the profile of OL-water and sediment. Additionally, most of P bound by the M-LaFeBT capping layer (approximately 77%) was stable under natural pH and reducing conditions. The phosphate adsorption ability for M-LaFeBT was much higher than that for M-FeBT, and the QMAX value for the former was 4.86 times higher than that for the latter. M-LaFeBT capping gave rise to a higher reduction of DGT-labile concentration in the profile of OL-water and sediment than M-FeBT capping. The P adsorbed by the M-LaFeBT capping layer was more stable than that by the M-FeBT capping layer. Results of this study demonstrate that M-LaFeBT is promising for utilization as an active capping material to intercept sedimentary P release into OL-water.