A pot experiment was carried out on brown soil polluted by dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) to investigate the effects of biochar (BC) derived from corn straw and Fe–Mn oxide modified biochar composites (FMBC) on the bioavailability of DBP and DEHP, as well as ecosystem responses in rhizosphere soil after wheat ripening. The results indicate that the application of BC and FMBC significantly increases soil organic matter, pH, available nitrogen (AN), Olsen phosphorus, and available potassium (AK); reduces the bioavailability of DBP and DEHP; enhances the activities of dehydrogenase, urease, protease, β-glucosidase, and polyphenol oxidase; and decreases acid phosphatase activity. No changes in richness and diversity, which were measured by Illumina MiSeq sequencing, were observed following BC and FMBC application. The bacterial community structure and composition varied with DBP/DEHP concentrations and BC/FMBC additions in a nonsystematic way and no significant trends were observed. In addition, FMBC exhibited better performance in increasing soil properties and decreasing the bioavailability of DBP and DEHP compared with BC. Hence, the FMBC amendment may be a promising way of developing sustainable agricultural environmental management.

Two radon measurement stations located to the north and south of a NORM (Naturally Occurring Radioactive Materials) repository of phosphogypsum (southwest of Europe) were used to monitor radon behavior during 2018. The stations are located at opposing sides of the repository, one in Huelva City to the north and other one in a rural area to the south. This setup aimed to identify the influence of the NORM repository on each station and use radon levels as a marker of atmospheric transport in the local area. To achieve this, a comparison was carried out with other coastal stations in the south of Spain, finding higher average concentrations in Huelva City, ~3.3 Bq m⁻³. Hierarchical clustering was applied to identify days with different radon patterns at each Huelva station, detecting possible local radon transport events from the repository. Three events were investigated with WRF (Weather Research and Forecasting) and FLEXPART-WRF (FLEXible PARTicle dispersion model). It was found that both sampling sites required atmospheric stagnant conditions to reach high radon concentration. However, under these conditions the urban station showed high radon regardless of wind direction while the rural station also required radon transport from the repository, either directly or indirectly.

For many years, the dispersal of modified clay (MC) has been used to control harmful algal blooms (HABs) in coastal waters of China. MC flocculation efficiency can be influenced by many factors in variable and complex natural environments, including high concentrations of dissolved organic matter (DOM) in the water to be treated. Since many HABs occur in nearshore waters where DOM concentrations are high, this is a significant problem that requires urgent attention. This study involved the use of humic acid as a representative form of DOM to study the influence of organic matter on the MC flocculation process. At high concentrations, humic acid was adsorbed onto MC particles, resulting in a decrease in surface potential and an increase in electrostatic repulsion between the clay particles; this decreased the MC settling rate and increased the water clarification time. Flocs were characterized by their relatively small particle size, high particle concentration, and low collision efficiency, which together resulted in slow clarification of the water after MC spraying. Based on the mechanism of the DOM-MC interaction and combined with the Derjaguin-Landau-Verwey-Overbeek theory and theoretical considerations of clay surface modification, the “ionic atmosphere compression” method was used to improve MC flocculation efficiency in high-organic water. This method increased the ionic strength of the clay stock solution by adding salt, thereby compressing the ionic atmosphere of MC particles and lowering the potential barrier, allowing the MC particles in the treated water to flocculate rapidly and form large flocs, followed by further floc growth and rapid settling via differential sedimentation. The settling rate of MCs improved by a factor of two and the removal efficiency of the HAB cells increased by 7–28%. This study provides important baseline information that will extend the application of MC to HAB control in water bodies with high organic loadings.

Interest in the potential human health of semi-volatile organic chemicals (SVOCs) in indoor and outdoor environments has made the exposure assessment and source appointment a priority. In this study, paired indoor and outdoor atmospheric fine particle (PM₂.₅) samples were collected from 15 homes representing five typical urban cities in southern China. Four typical SVOCs, including 16 congeners of polycyclic aromatic hydrocarbons (PAHs), 13 congeners of organophosphorus flame retardants (OPFRs) and 8 congeners of polybrominated diphenyl ethers (PBDEs), as well as tetrabromobisphenol A (TBBPA) and its three debrominated congeners were analyzed. The highest total concentrations were found for OPFRs, followed by PAHs, PBDEs, and TBBPA. The indoor concentrations of two alkyl-OPFR isomers, tributylphosphate (TBP) and tris (2-butoxyethyl) phosphate (TBEP), were 4.3 and 11 times higher, respectively, than those of outdoors (p < 0.05). Additionally, the ratios of indoor to outdoor concentrations of alkyl-OPFR isomers varied greatly, suggesting that these compounds originated mainly from different household goods and products used in individual homes. The outdoor concentrations of PAHs and highly brominated PBDEs (BDE-209) typically exceeded the indoor concentrations. Significant correlations were also found between indoor and outdoor PM₂.₅ samples for PAHs and BDE-209, indicating that outdoor sources such as vehicle exhausts and industrial activities strongly influence their atmospheric occurrence. Additionally, the concentrations of debrominated TBBPA derivatives were higher than those of TBBPA in over 33% of both indoor and outdoor air particle samples. Nevertheless, our results indicated that inhalation exposure to typical SVOCs posed no non-carcinogenic risks to the human body. Although we observed notable differences in the sources, occurrences, and distributions of typical SVOC congeners, more studies using matched samples are still needed to unambiguously identify important indoor and outdoor sources in order to accurately assess the contributions of different sources and the associated human exposure risks.

Landfills, as well as other waste management facilities are well-known bioaerosols sources. These places may foment antibiotic-resistance in bacterial bioaerosol (A.R.B.) due to inadequate pharmaceutical waste disposal. This issue may foster the necessity of using last-generation antibiotics with extra costs in the health care system, and deaths. The aim of this study was to reveal the multi-antibiotic resistant bacterial bioaerosol emitted by a sanitary landfill and the surrounding area. We evaluated the influence of environmental conditions in the occurrence of A.R.B. and biological risk assessment. Antibiotic resistance found in the bacteria aerosols was compared with the AWaRE consumption classification. We used the BIOGAVAL method to assess the workers' occupational exposure to antibiotic-resistant bacterial bioaerosols in the landfill. This study confirmed the multi-antibiotic resistant in bacterial bioaerosol in a landfill and in the surrounding area. Obtained mean concentrations of bacterial bioaerosols, as well as antibiotic-resistant in bacterial bioaerosol (A.R.B.), were high, especially for fine particles that may be a threat for human health. Results suggest the possible risk of antibiotic-resistance interchange between pathogenic and non-pathogenic species in the landfill facilities, thus promoting antibiotic multi-resistance genes spreading into the environment.

The presence of manufactured nano-objects (MNOs) in various consumer or their (future large-scale) use as nanoagrochemical have increased with the rapid development of nanotechnology and therefore, concerns associated with its possible ecotoxicological effects are also arising. MNOs are releasing along the product life cycle, consequently accumulating in soils and other environmental matrices, and potentially leading to adverse effects on soil biota and their associated processes. Earthworms, of the group of Oligochaetes, are an ecologically significant group of organisms and play an important role in soil remediation, as well as acting as a potential vector for trophic transfer of MNOs through the food chain. This review presents a comprehensive and critical overview of toxic effects of MNOs on earthworms in soil system. We reviewed pathways of MNOs in agriculture soil environment with its expected production, release, and bioaccumulation. Furthermore, we thoroughly examined scientific literature from last ten years and critically evaluated the potential ecotoxicity of 16 different metal oxide or carbon-based MNO types. Various adverse effects on the different earthworm life stages have been reported, including reduction in growth rate, changes in biochemical and molecular markers, reproduction and survival rate. Importantly, this literature review reveals the scarcity of long-term toxicological data needed to actually characterize MNOs risks, as well as an understanding of mechanisms causing toxicity to earthworm species. This review sheds light on this knowledge gap as investigating bio-nano interplay in soil environment improves our major understanding for safer applications of MNOs in the agriculture environment.

Engine oil-derived ash particles emitted from internal combustion (IC) engines are unwanted by-products, after oil is involved in in-cylinder combustion process. Since they typically come out together with particulate emissions, no detail has been reported about their early-stage particles other than agglomerated particles loaded on aftertreatment catalysts and filters. To better understand ash formation process during the combustion process, differently formulated engine oils were dosed into a fuel system of a gasoline direct injection (GDI) engine that produces low soot mass emissions at normal operating conditions to increase the chances to find stand-alone ash particles separated from soot aggregates in the sub-20-nm size range. In addition to them, ash/soot aggregates in the larger size range were examined using scanning transmission electron microscopy (STEM)-X-ray electron dispersive spectroscopy (XEDS) to present elemental information at different sizes of particles from various oil formulations. The STEM-XEDS results showed that regardless of formulated oil type and particle size, Ca, P and C were always contained, while Zn was occasionally found on relatively large particles, suggesting that these elements get together from an early stage of particle formation. The S, Ca and P K-edge X-ray absorption near edge structure (XANES) analyses were performed for bulk soot containing raw ash. The linear combination approach & cross-checking among XANES results proposed that Ca₅(OH)(PO₄)₂, Ca₃(PO₄)₂ and Zn₃(PO₄)₂ are potentially major chemical compounds in raw ash particles, when combined with the STEM-XEDS results. Despite many reports that CaSO₄ is a major ash chemical when ash found in DPF/GFP systems was examined, it was observed to be rarely present in raw ashes using the S K-edge XANES analysis, suggesting ash transformation.

Pesticides may alter soil microbial community structure or diversity, but their impact on microbial co-occurrence patterns remains unclear. Here, the effect of the widely used neonicotinoid insecticide thiamethoxam on the bacterial community in five arable soils was deciphered using the 16S rRNA gene amplicon sequencing technique. The degradation half-life of thiamethoxam in nonsterilized soils was significantly lower than that in sterilized soils, suggesting a considerable contribution from biodegradation. Soil bacterial community diversity diminished in high concentration thiamethoxam treatment and its impact varied with treatment concentration and soil type. Bacterial co-occurrence network complexity significantly decreased after exposure to thiamethoxam. Under thiamethoxam stress, the relative changes in bacterial co-occurrence networks were closely related (the majority of p-values < 0.05) to the soil physicochemical properties, yet the diversity and dominant phyla were slightly related (the majority of p-values > 0.05). Additionally, three bacterial genera, Sphingomonas, Streptomyces, and Catenulispora, were identified to be relevant to the degradation of thiamethoxam in soils. This finding deciphers the succession of the bacterial community under thiamethoxam stress across multiple soils, and emphasizes the potential role of physicochemical properties in regulating the ecotoxicological effect of pesticides on the soil microbiome.

Emerging evidence has demonstrated that exposure to fine particulate matter (PM₂.₅) is a risk factor for lipid metabolic disorders in the liver. However, the effects of PM₂.₅ exposure time duration on hepatic lipid metabolism remain unknown. In this study, C57BL/6 mice were randomly divided into ambient PM₂.₅ (PM) or filtered air (FA) exposure chamber for short-term (4 weeks) or long-term (24 weeks) exposure via a whole body exposure system. We measured hepatic triglyceride and free fatty acid levels and analyzed the alteration of lipometabolism-related molecules in the liver. We found that triglyceride levels were significantly elevated in both short-term and long-term PM₂.₅-exposed mice and free fatty acid levels were increased after long-term PM₂.₅ exposure. Besides, enzymes for lipolysis and fatty acid oxidation in the liver were inhibited after short-term PM₂.₅ exposure but adaptively enhanced after long-term PM₂.₅ exposure. Furthermore, molecules for fatty acid uptake were down-regulated in the short-term PM₂.₅-exposed mice whereas molecules for lipid export were induced after long-term PM₂.₅ exposure. Therefore, ambient PM₂.₅ exposure disturbed hepatic lipid metabolism and the effects varied in different exposure duration. These findings in mice provide new insight into the biological basis of PM₂.₅-induced human metabolic dysfunction and specific strategies may be applied based on different exposure time periods.

Condensable particulate matter (CPM) is quickly formed by several gaseous substances in flue gas after emission and belongs to primary particulate matter emitted into the atmosphere by stationary sources. Many studies have shown that current CPM emissions from coal-fired stationary sources far exceed filterable particulate matter, and the issue of CPM emissions has attracted widespread attention. The current research on CPM mainly focuses on its emission characteristics in stationary sources and its migration characteristics in pollutant-controlled equipment, lacking the characteristics of CPM directly generated by fuel combustion. In this study, a one-dimensional flame furnace is used as a stable source of flue gas in the laboratory. The concentration (including inorganic and organic components) and chemical composition (including water-soluble ions, metal elements, and organic matters) of CPM are obtained by the combustion of three kinds of coal (Inner Mongolia lignite, Jinjie bitumite, and Ningxia anthracite) that China consumes in large amounts. The characteristics of CPM including emission factors obtained from different kinds of coal under various experimental conditions are comparatively analyzed. Moreover, a scanning electron microscope–energy-dispersive spectrometer is used to observe the morphology and elemental composition of CPM collected on the filter membrane after the combustion of different kinds of coal. Results show that CPM is mainly in the form of droplets or spheres, and heavy metal elements such as Hg, As, Se, and Sb are detected. These valuable data will enrich people’s understanding of the characteristics of CPM generated by coal combustion and can provide data references for evaluating the influence of CPM on the environment.