Waste plastics can be degraded to nanoplastics (NPs, diameter<1 μm) by natural forces. NPs not only directly affect aquatic organisms but also adsorb other pollutants, causing combined pollution. Glyphosate is one of the most widely used herbicides and is commonly monitored in freshwater systems. In this study, the effects of the combined toxicity of polystyrene cationic amino-modified nanoparticles (nPS-NH₂) and glyphosate on a blue-green alga, Microcystis aeruginosa, were investigated. Our results demonstrated that 5 mg/L glyphosate had a strong inhibitory effect on M. aeruginosa (the 96-h inhibitory rate was 27%), while 5 mg/L nPS-NH₂ had no apparent effect on the growth of M. aeruginosa. Interestingly, nPS-NH₂ combined with glyphosate showed antagonistic effects on the inhibition of algal growth because nPS-NH₂ displayed a strong adsorption capacity for glyphosate, which significantly alleviated the inhibitory effect of glyphosate on M. aeruginosa growth. However, the presence of glyphosate enhanced the stability of the dispersion system, which allowed more nPS-NH₂ to adsorb on the surface of M. aeruginosa and may result in greater enrichment of nPS-NH₂ in the food chain to show potential repercussions to human life. Our current study provides a new theoretical basis for the combined effects of NPs and pesticide pollution.

Agriculture is today indispensably connected with enormous use of pesticides. Despite tough regulation, their entrance into soil cannot be excluded and they might enter soil organisms and plants and continue further to terrestrial food chains. This study was conducted to investigate the bioaccumulation of two pesticides currently used in large amounts, the insecticide chlorpyrifos (CLP) and the fungicide tebuconazole (TBZ). Their detailed uptake kinetics in the model earthworm species Eisenia andrei were measured in two arable soils differing in organic carbon content (1.02 and 1.93% respectively). According to our results, a steady state was reached after 3–5 days for both pesticides and soils. The values of bioaccumulation factors calculated at the steady state ranged from 4.5 to 6.3 for CLP and 2.2–13.1 for TBZ. Bioaccumulation factors were also calculated as the ratio of uptake and elimination rate constants with results comparable with steady-state bioaccumulation factors. The results suggested that the degradation and bioaccumulation of tested compounds might be influenced by other factors than only total organic carbon (e.g. clay content). The lower Koc and hydrophobicity of TBZ relative to CLP probably led to higher availability of TBZ through pore water exposure. On the other hand, CLP's higher hydrophobicity probably caused an increase in availability by its additional uptake via ingestion. To enable a proper ecological risk assessment of current pesticides in soils, it is necessary to accurately determine their bioaccumulation in soil invertebrates. We believe that our study not only brings such information for two specific pesticides but also addresses key methodological issues in this area.

Polybrominated diphenyl ethers (PBDEs) were investigated by GC–NCI–MS in sediments collected from the Pearl River Delta (PRD) and Guiyu town, South China. The concentrations of ∑₃₉PBDEs and BDE 209 were in the ranges of 0.31–38.9 ng g⁻¹ and 12.2–488 ng g⁻¹ in the PRD, and 2.57–21,207 ng g⁻¹ and 7.02–66,573 ng g⁻¹ in Guiyu, respectively. The levels of PBDEs in Dongjiang River (DJ), Zhujiang River (ZJ), and Beijiang River (BJ), and Guiyu (GY) followed the order: GY > DJ > ZJ > BJ. The very high PBDE concentration (87,779 ng g⁻¹) was detected at G1 sediment in Guiyu compared with those in sediments from other regions around the world. The PBDE mixtures detected were mainly comprised of penta-, octa-, and deca-BDEs, in which deca-BDE was the dominant constituent. The abundant congeners, excluding BDE-209, were BDE-47, BDE-99, and BDE-183, suggesting the diverse use of commercial products containing these congeners in this region. The concentrations of major congeners were significantly correlated with total organic carbon (TOC) contents (p < .01). A good regression between the logarithmic TOC-normalized BDE average concentrations and their log Kₒw confirmed that the sorption of PBDEs on sediment organic matter governed their spatial distribution, transport, and fate in the sediments. Furthermore, risk quotients (RQs) derived from concentrations of PBDEs in sediments from our study may pose high ecological risks to exposure of benthic organisms.

Lead, a pervasive environmental hazard worldwide, causes a wide range of physiological and biochemical destruction, including metabolic dysfunction. Grape seed proanthocyanidin extract (GSPE) is a natural production with potential metabolic regulation in liver. This study was performed to investigate the protective role of GSPE against lead-induced metabolic dysfunction in liver and elucidate the potential molecular mechanism of this event. Wistar rats received GSPE (200 mg/kg) daily with or without lead acetate (PbA, 0.5 g/L) exposure for 56 d. According to biochemical and histopathologic analysis, GSPE attenuated lead-induced metabolic dysfunction, oxidative stress, and liver dysfunction. Liver gene expression profiling was assessed by RNA sequencing and validated by qRT-PCR. Expression of some genes in peroxisome proliferator-activated receptor alpha (PPARα) signaling pathway was significantly suppressed in PbA group and revived in PbA + GSPE group, which was manifested by Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis and validated by western blot analysis. This study supports that dietary GSPE ameliorates lead-induced fatty acids metabolic disturbance in rat liver associated with PPARα signaling pathway, and suggests that dietary GSPE may be a protector against lead-induced metabolic dysfunction and liver injury, providing a novel therapy to protect liver against lead exposure.

DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is the main active ingredient in an emerging water environment antifoulant, the toxicity and environmental impacts of which need to be further investigated. Thus, this study examined the toxicity of DCOIT on Nile tilapia (Oreochromis niloticus), including its effects on behavior, respiration and energy metabolism as well as the role of endoplasmic reticulum stress (ER stress) in mediating its toxicity and metabolic changes. The changes in fish behavior, respiration, neuronal signal transmission, energy metabolism, ER stress, and liver histology were examined via acute (4 days) and chronic (28 days) exposures to 0, 3, 15, 30 μg/L DCOIT in vivo. Additionally, ER stress levels were measured in 24-h periods of hepatocyte exposure to 0, 3, 15, 30 and 300 μg/L DCOIT in vitro. The hyper-locomotor activities decreased, but the respiration rate increased after a 4-day acute exposure period, indicating that DCOIT exposure altered fish energy metabolism. After acute exposure at a low DCOIT concentration, the activation of ER stress induced triglyceride accumulation in the liver. After chronic exposure for 28 days, the prolonged ER stress induced a series of pathological cellular changes. At the cellular level, exposure to a high DCOIT concentration induced ER stress in the hepatocytes. In addition, as a neurotoxin, DCOIT has the potential to disrupt the neurotransmission of the cholinergic system, resulting in motor behavior disruption. This study demonstrates that DCOIT plays a role in time- and concentration-dependent toxicity and that changes in lipid metabolism are directly related to endoplasmic reticulum function after exposure to an antifouling agent. This work advances the understanding of the toxic mechanism of DCOIT, which is necessary for its evaluation.

Carbon nanotubes can be either toxic or beneficial to plant growth and can also modulate toxicity of organic contaminants through surface sorption. The complex interacting toxic effects of carbon nanotubes and organic contaminants in plants have received little attention in the literature to date. In this study, the toxicity of multiwall carbon nanotubes (MWCNT, 50 mg/L) and paraquat (MV, 0.82 mg/L), separately or in combination, were evaluated at the physiological and the proteomic level in Arabidopsis thaliana for 7–14 days. The results revealed that the exposure to MWCNT had no inhibitory effect on the growth of shoots and leaves. Rather, MWCNT stimulated the relative electron transport rate and the effective photochemical quantum yield of PSII value as compared to the control by around 12% and lateral root production up to nearly 4-fold as compared to the control. The protective effect of MWCNT on MV toxicity on the root surface area could be quantitatively explained by the extent of MV adsorption on MWCNT and was related to stimulation of photosynthesis, antioxidant protection and number and area of lateral roots which in turn helped nutrient assimilation. The influence of MWCNT and MV on photosynthesis and oxidative stress at the physiological level was consistent with the proteomics analysis, with various over-expressed photosynthesis-related proteins (by more than 2 folds) and various under-expressed oxidative stress related proteins (by about 2–3 folds). This study brings new insights into the interactive effects of two xenobiotics (MWCNT and MV) on the physiology of a model plant.

Hypoxia is as an endocrine disruptor, and, in crustaceans, the energy metabolic consequences of hypoxia in the brain tissue are still poorly understood. We combined gas chromatography-mass spectrometry (GC-MS)-based metabolomic analysis and high-throughput RNA sequencing to evaluate the metabolic effects and subjacent regulatory pathways in the brain tissue of the male Oriental river prawn (Macrobrachium nipponense) in response to hypoxia and reoxygenation. We recorded LC₅₀ and heartbeats per minute of male M. nipponense juveniles. Hypoxia resulted in the generation of reactive oxygen species in the brain cells and alterations in gene expression and metabolite concentrations in the prawn brain tissue in a time-dependent manner. The transcriptomic analyses revealed specific changes in the expression of genes associated with metabolism pathways, which was consistent with the changes in energy metabolism indicated by the GC-MS metabolomic analysis. Quantitative real-time polymerase chain reaction and western blot confirmed the transcriptional induction of these genes because of hypoxia. The lactate levels increased significantly during hypoxia and decreased to normal after reoxygenation; this is consistent with a shift towards anaerobic metabolism, which may cause metabolic abnormalities in the brain tissue of M. nipponense. Overall, these results are consistent with metabolic disruption in the brain of M. nipponense exposed to hypoxia and will help in understanding how crustacean brain tissue adapts and responds to hypoxia and reoxygenation.

Frequent low visibility, haze pollution caused by heavy fine particulate matter (PM₂.₅) loading, has been entailing significant environmental issues and health risks in China since 2013. A substantial fraction of bioaerosols was observed in PM (1.5–15%) during haze periods with intensive pollution. However, systematic and consistent results of the variations of bioaerosol characteristics during haze pollution are lacking. The role of bioaerosols in air quality and interaction with environment conditions are not yet well characterized. The present article provides an overview of the state of bioaerosol research during haze episodes based on numerous recent studies over the past decade, focusing on concentration, size distribution, community structure, and influence factors. Examples of insightful results highlighted the characteristics of bioaerosols at different air pollution levels and their pollution effects. We summarize the influences of meteorological and environmental factors on the distribution of bioaerosols. Further studies on bioaerosols, applying standardized sampling and identification criteria and investigating the influence of mechanisms of environmental or pollution factors on bioaerosols as well as the sources of bioaerosols are proposed.

CuO engineered nanoparticles (NPs) are of increasing concern due to their extensive use in daily life and adverse effect on aquatic organisms. The investigations on the toxicity of CuO NPs to aquatic plants through uptake from roots versus fronds are limited. This paper discusses the interactions of CuO NPs with Lemna minor, a floating plant. After CuO NPs (150 μg L⁻¹) exposure for 7 days, the frond number, frond surface area and dry weights of whole plants significantly decreased by 32%, 47% and 33%; the responses were dose-dependent. Microscopy imaging showed that the epidermis was severely damaged in fronds, edges were severely sloughed off and cell integrity was damaged in roots. Shrinkage of both chloroplast and starch grains were observed in the frond cells. Internalization of CuO NPs in root and frond cells during CuO NPs (1 mg L⁻¹) exposure was confirmed with the root Cu levels of Lemna minor being three times higher than the fronds by using transmission electron microscopy and flame atomic absorption spectrophotometry. Reactive oxygen species, mainly H₂O₂ (increased by 56%) and ·OH (increased by 57%), accumulated in Lemna minor tissues in response to CuO NPs exposure. Moreover, chloroplasts were confirmed as a site of ROS production. These findings are helpful for better understanding the biological responses of aquatic plants upon NPs exposure.

In this study, we examined the removal of arsenite (As(III)) and arsenate (As(V)) by perilla leaf-derived biochars produced at 300 and 700 °C (referred as BC300 and BC700) in aqueous environments. Results revealed that the Langmuir isotherm model provided the best fit for As(III) and As(V) sorption, with the sorption affinity following the order: BC700-As(III) > BC700-As(V) > BC300-As(III) > BC300-As(V) (QL = 3.85–11.01 mg g⁻¹). In general, As removal decreased (76–60%) with increasing pH from 7 to 10 except for the BC700-As(III) system, where notably higher As removal (88–90%) occurred at pH from 7 to 9. Surface functional moieties contributed to As sequestration by the biochars examined here. However, significantly higher surface area and aromaticity of BC700 favored a greater As removal compared to BC300, suggesting that surface complexation/precipitation dominated As removal by BC700. Arsenic K-edge X-ray absorption near edge structure (XANES) spectroscopy demonstrated that up to 64% of the added As(V) was reduced to As(III) in BC700- and BC300-As(V) sorption experiments, and in As(III) sorption experiments, partial oxidation of As(III) to As(V) occurred (37–39%). However, XANES spectroscopy was limited to precisely quantify As binding with sulfur species as As2S3-like phase. Both biochars efficiently removed As from natural As-contaminated groundwater (As: 23–190 μg L⁻¹; n = 12) despite in the presence of co-occurring anions (e.g., CO3²⁻, PO4³⁻, SO4²⁻) with the highest levels of As removal observed for BC700 (97–100%). Overall, this study highlights that perilla leaf biochars, notably BC700, possessed the greatest ability to remove As from solution and groundwater (drinking water). Significantly, the integrated spectroscopic techniques advanced our understanding to examine complex redox transformation of As(III)/As(V) with biochar, which are crucial to determine fate of As on biochar in aquatic environments.