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.

Glyphosate is the active ingredient of the commercial formulation Roundup®, which is used worldwide. This study aimed to investigate the toxic effects of pure glyphosate or Roundup® on pregnant mice and their fetuses during pregnancy. From gestation days (GDs) 1–19, ICR mice were orally administered distilled water, 0.5% glyphosate solution or 0.5%-glyphosate Roundup® solution. The ovaries and serum were collected at GD19. The results showed decreases in body weight gain and, ovary and liver weight in glyphosate-treated mice. Additionally, histopathological alterations in the ovary including increased atretic follicles, interstitial fibrosis and decreased mature follicles were observed in the groups treated with glyphosate. The serum concentrations of both progesterone and estrogen were markedly altered after glyphosate exposure, and there were also changes in the expression of GnRH, LHR, FSHR, 3β-HSD and Cyp19a1 genes at the hypothalamic-pituitary-ovarian axis. Furthermore, oxidative stress was observed in the treated mice, increasing the activity of T-AOC, CAT and GSH-Px, as well as the MDA content in both the serum and ovary. With regard to litters, the sex ratio was significantly altered by pure glyphosate. These results show that glyphosate is able to cause several effects on pregnant mice, such as ovarian failure, interference with hormone secretion by affecting the steroidogenesis-related gene expression, and oxidative stress. The sex ratio of litters was also influenced by prenatal exposure to pure glyphosate.

Bulk Cu compounds such as Cu(OH)₂ are extensively used as pesticides in agriculture. Recent investigations suggest that Cu-based nanomaterials can replace bulk materials reducing the environmental impacts of Cu. In this study, stress responses of alfalfa (Medicago sativa L.) seedlings to Cu(OH)₂ nanoparticle or compounds were evaluated. Seeds were immersed in suspension/solutions of a Cu(OH)₂ nanoform, bulk Cu(OH)₂, CuSO₄, and Cu(NO₃)₂ at 25 and 75 mg/L. Six days later, the germination, seedling growth, and the physiological and biochemical responses of sprouts were evaluated. All Cu treatments significantly reduced root elongation (average = 63%). The ionic compounds at 25 and 75 mg/L caused a reduction in all elements analyzed (Ca, K, Mg, P, Zn, and Mn), excepting for S, Fe and Mo. The bulk-Cu(OH)₂ treatment reduced K (48%) and P (52%) at 75 mg/L, but increased Zn at 25 (18%) and 75 (21%) mg/L. The nano-Cu(OH)₂ reduced K (46%) and P (48%) at 75 mg/L, and also P (37%) at 25 mg/L, compared with control. Confocal microscopy images showed that all Cu compounds, at 75 mg/L, significantly reduced nitric oxide, concurring with the reduction in root growth. Nano Cu(OH)₂ at 25 mg/L upregulated the expression of the Cu/Zn superoxide dismutase gene (1.92-fold), while ionic treatments at 75 mg/L upregulated (∼10-fold) metallothionein (MT) transcripts. Results demonstrated that nano and bulk Cu(OH)₂ compounds caused less physiological impairments in comparison to the ionic ones in alfalfa seedlings.

The clean-up effort that is occurring across the region affected by the 2011 Fukushima Daiichi Nuclear Power Plant accident is unprecedented in its magnitude as well as the financial cost that will eventually result. A major component of this remediation is the stripping of large volumes of material from the land surface, depositing this into large waste storage bags before placing these 1 cubic meter bags into specially constructed stores across Fukushima Prefecture.In this work, using an unmanned aerial vehicle to perform radiological surveys of a site, the time-resolved distribution of contamination during the construction of one of these waste storage sites was assessed. The results indicated that radioactive material was progressively leaching from the store into the surrounding environment. A subsequent survey of the site conducted eight months later revealed that in response to this survey and remedial actions, the contamination issue once existing on this site had been successfully resolved. Such results highlight the potential of low-altitude unmanned aerial systems to easily and rapidly assess site-wide changes over time – providing highly-visual results; therefore, permitting for prompt remedial actions to be undertaken as required.Use of UAV radiation mapping and airborne photogrammetry to produce a time-resolved assessment of remediation efforts within a Fukushima temporary storage facility.

Soil is a heterogeneous porous media that is comprised of a variety of organo-mineral aggregates. Sorption of heavy metals onto these composite solids is a key process that controls heavy metal mobility and fate in the natural environment. Pollution from a combination of heavy metals is common in soil, therefore, understanding the competitive binding behavior of metal ions to organo-mineral composites is important in order to predict metal mobility and fate. In this study, batch experiments were paired with spectroscopic studies to probe the sorption characteristics of ternary CdNiCu sorbates to a binary organo-goethite composite made with Bacillus cereus cells. Scanning electron microscopy shows that goethite nano-sized crystals are closely associated with the bacterial surfaces. Sorption experiments show a larger adsorptivity and affinity for Cu than Cd/Ni on goethite and B. cereus, and the goethite–B. cereus composite. X-ray photoelectron spectroscopy reveals that carboxylate and phosphate functional moieties present on the bacterial cell walls are primarily responsible for metal sorption to the goethite–B. cereus composite. Synchrotron-based X-ray fluorescence shows that Cu and Ni are predominately associated with the bacterial fraction of the goethite–B. cereus composite, whereas Cd is mainly associated with the goethite fraction. The findings of this research have important implications for predicting the mobility and fate of heavy metals in soil multi-component systems.

Benzene series (BTEX) pollutants which are generated by traffic can deposit (build-up) on urban road surfaces. When they are washed-off by stormwater runoff, BTEX are toxic to ecological and human health if the stormwater is reused. To understand the risk posed by BTEX, it is essential to have an in-depth investigation on BTEX build-up, one of the most important stormwater pollutant processes. This study analysed the relationship between BTEX build-up and BTEX build-up's influential factors. The outcomes confirmed an important role of climatic factors (particularly temperature) on influencing BTEX build-up. This has not been considered in previous stormwater studies although this has been widely focused in atmospheric pollution. BTEX build-up loads were generally higher and the variability was low in dry seasons with low temperature such as winter and spring. Additionally, the influence of temperature on BTEX build-up on urban road surfaces is more important in the case of larger particles (such as >75 μm) than smaller particles. The study also showed that petrol station areas have a potential to export stormwater runoff with high BTEX concentrations, compared to typical urban roads. This is particularly applicable in winter and spring. These outcomes can provide useful guidance to improving stormwater quality modelling approaches, especially relevant to estimation of BTEX concentrations in the stormwater.

The total volume of the coal processing wastes (filter cakes) produced by Russia, China, and India is as high as dozens of millions of tons per year. The concentrations of CO and CO₂ in the emissions from the combustion of filter cakes have been measured directly for the first time. They are the biggest volume of coal processing wastes. There have been many discussions about using these wastes as primary or secondary components of coal-water slurries (CWS) and coal-water slurries containing petrochemicals (CWSP). Boilers have already been operationally tested in Russia for the combustion of CWSP based on filter cakes. In this work, the concentrations of hazardous emissions have been measured at temperatures ranging from 500 to 1000°С. The produced CO and CO₂ concentrations are shown to be practically constant at high temperatures (over 900°С) for all the coal processing wastes under study. Experiments have shown the feasibility to lowering the combustion temperatures of coal processing wastes down to 750–850°С. This provides sustainable combustion and reduces the CO and CO₂ emissions 1.2–1.7 times. These relatively low temperatures ensure satisfactory environmental and energy performance of combustion. Using CWS and CWSP instead of conventional solid fuels significantly reduces NOₓ and SOₓ emissions but leaves CO and CO₂ emissions practically at the same level as coal powder combustion. Therefore, the environmentally friendly future (in terms of all the main atmospheric emissions: CO, CO₂, NOₓ, and SOₓ) of both CWS and CWSP technologies relies on low-temperature combustion.

Effects of photochemical and microbial degradation on variations in composition and molecular-size of dissolved organic matter (DOM) from different sources (algal and soil) and the subsequent influence on Cu(II) binding were investigated using UV–Vis, fluorescence excitation-emission matrices coupled with parallel factor analysis, flow field-flow fractionation (FlFFF), and metal titration. The degradation processes resulted in an initial rapid decline in the bulk dissolved organic carbon and chromophoric and fluorescent DOM components, followed by a small or little decrease. Specifically, photochemical reaction decreased the aromaticity, humification and apparent molecular weights of all DOM samples, whereas a reverse trend was observed during microbial degradation. The FlFFF fractograms revealed that coagulation of both protein- and humic-like DOM induced an increase in molecular weights for algal-DOM, while the molecular weight enhancement for allochthonous soil samples was mainly attributed to the self-assembly of humic-like components. The Cu(II) binding capacity of algal-derived humic-like and fulvic-like DOM consistently increased during photo- and bio-degradation, while the soil-derived DOM exhibited a slight decline in Cu(II) binding capacity during photo-degradation but a substantial increase during microbial degradation, indicating source- and degradation-dependent metal binding heterogeneities. Pearson correlation analysis demonstrated that the Cu(II) binding potential was mostly related with aromaticity and molecular size for allochthonous soil-derived DOM, but was regulated by both DOM properties and specific degradation processes for autochthonous algal-derived DOM. This study highlighted the coupling role of inherent DOM properties and external environmental processes in regulating metal binding, and provided new insights into metal-DOM interactions and the behavior and fate of DOM-bound metals in aquatic environments.

Given the sub-lethal risks of synthetic surfactants, rhamnolipid is a promising class of biosurfactants with the potential to promote the bioavailability of polycyclic aromatic hydrocarbons (PAHs), to provide a favorable substitute for synthetic surfactants. However, few previous studies have integrated the behavior and mechanism behind rhamnolipid-influenced PAH biosorption and biodegradation. This is, to our knowledge, the first report of a bacterial envelope regulated link between phenanthrene (PHE) biosorption and biodegradation by rhamnolipid-induced PHE-degrading strain Pseudomonas sp. Ph6. Rhamnolipid (0─400 mg L−1) can change the cell-surface zeta potential, cell surface hydrophobicity (CSH), cell ultra-microstructure and functional groups, and then alter PHE biosorption and biodegradation of Ph6. Greater amounts of PHE sorbed on cell envelopes results in more PHE diffusing into cytochylema, thus favoring PHE intracellular biodegradation of Ph6. Rhamnolipid (≤100 mg L−1) could change the microstructures and functional groups of cell envelopes of Ph6, enhance the cell-surface zeta potential and CSH, thus consequently favor PHE biosorption and biodegradation by strain Ph6. By contrast, rhamnolipid at higher concentrations (≥200 mg L−1) hindered PHE biosorption and biodegradation. Rhamnolipid, as a biosurfactant, can be successfully utilized as an additive to improve the microbial biodegradation of PAHs in the environments.