Environmental Chemistry Letters最新文献

Health impact of atmospheric particulate matter is traditionally assessed using mass concentrations of particulate matter, yet epidemiological findings reveal inconsistencies, and respiratory and cardiovascular diseases often correlate more strongly with the oxidative potential of particulate matter, which reflects its ability to generate reactive oxygen species and induce oxidative stress. Here we review the oxidative potential of particulate matter in more than 200 field studies, with focus on epidemiological evidence, methods, influencing factors, and the contribution of the emission sources. Methods to assess the oxidative potential include electron spin resonance, the dithiothreitol and dichlorofluorescein assays, antioxidant depletion, and hydroxyl radical production. Major influencing factors comprise particle size and the presence of metals and carbonaceous aerosols. We observed that the oxidative potential varies substantially depending on particle size, the presence of transition metals and quinones, and emission sources such as biomass burning and traffic. Existing assays vary in their sensitivity to specific components of particulate matter, making comparisons between studies challenging. Methodological decisions such as the choice of extraction solvents and filter types can significantly change the measured oxidative potential. Overall, there is a need for standardized protocols and longitudinal studies linking oxidative potential to health outcomes.

Halogenated organic compounds are widely occurring persistent pollutants originating from herbicides, insecticides, and other industrial products, calling for advanced methods of environmental remediation. Here, we review the microbial processes allowing to remove the halogen atoms, namely, fluorine, bromine, and chlorine, from the pollutants. We discuss the fate of halogenated organic compounds, the microbial halogen cycle, bacterial dehalogenases, and the mechanisms of dehalogenation, metagenomics, and genetic modifications. Bacterial dehalogenases include hydrolytic, reductive, oxidative, and glutathione-dependent dehalogenases. Dehalogenation mechanisms comprise hydrolytic, reductive, and oxygenolytic dehalogenation.

Global warming, pollution, and industrial agriculture are degrading soils worldwide and threatening food security, thus calling for advanced methods to improve soil quality and fertility, and to sequester carbon. Here, we review the use of artificial humus with focus on the synthesis of artificial humus by hydrothermal carbonization of biomass. We detail the reaction mechanism, parameters controlling the reaction, differences between artificial and natural humus, laboratory and industrial production, biomass components, effects on soil nutrients and microbial biomass, remediation of saline-alkali land, and life cycle assessment. After reaction at 150–230 °C, the conversion rate is high, and the properties of artificial humus are very similar to those of natural humus. The application of this artificial humus improves soil nutrient availability, saline-alkali land, microbial characteristics, and the overall soil health. In saline-alkali soils, the application of artificial humus increases the cation exchange capacity up to 1.78 times, with a short-term pH decrease of 0.26–1.0 and an electrical conductivity decrease of 37–60 µS·cm⁻¹. Nevertheless, large-scale application of this technology still faces challenges such as high equipment investment costs, fluctuations in product characteristics between batches, and the lack of unified quality assessment standards.

Antimicrobial resistance is a major health issue that rapidly decreases the number of marketed chemical antibiotics that can cure microbial diseases, calling for alternative solutions. Here we review bacteriophage therapy using nanotechnological delivery with focus on definition and classification, dry powder formation, liposome encapsulation of bacteriophages, hydrogels, electrospinning of phages into nanofibers, and phage emulsions. Dry powder can be done by spray drying and lyophilization. Hydrogels include alginate, polyethylene glycol, polyvinyl glycol, nanocellulose, agarose, hyaluronan and poloxamer. We observed that bacteriophage therapy displays advantages such as self-replicating properties, and minimal disruption to the host microbiota. Recently developed lipid-based nanocarriers, hydrogels, and electrospun core–shell nanofibers have improved phage protection under harsh physiological conditions. Encapsulation using microfluidics-derived nanoemulsions and natural polymers allows for controlled, site-specific phage release and enhanced biofilm penetration. Surface modification using biomimetic coatings and biodegradable materials reduces immunogenicity and extends systemic circulation. Limitations of bacteriophage therapy comprise poor phage stability in physiological conditions, rapid removal by the immune system, limited penetration into biofilms, and the absence of standardized, scalable delivery systems. Clinical studies often focus solely on bacterial reduction while overlooking formulation integrity, delivery efficiency, and pharmacokinetics.

Recycling reclaimed wastewater, manure, and biosolids in agricultural soils is a sustainable technique of irrigation and fertilization in the context of the circular economy, yet the presence of contaminants such as pharmaceuticals induces the contamination of crop plants, food, and, in turn, humans. Here, we review the transfer of pharmaceuticals in crop plants with focus on pharmaceutical sources and properties, soil characteristics, root uptake, translocation, and accumulation. We discuss pharmaceutical accumulation in crop plants grown on soils amended with reclaimed wastewater, biosolids, and manure. The presence of pharmaceutical metabolites in plants is also summarized. We observed a decrease of the concentration and of the number of pharmaceuticals from wastewater to soils, then to plants, with typically less than 1% of the initial total pharmaceutical amount being detected in edible crop plants. Pharmaceutical accumulation decreases in the order of leaves, fruits, roots, and grain. Leafy vegetables showed the highest accumulation of pharmaceuticals, reaching few thousands of nanograms per gram dry weight. Pharmaceuticals can be degraded into metabolites that also accumulate in edible plants, yet their behaviour and risk for health are poorly known.

The increasing use of metal nanoparticles in industrial products has induced a global pollution, yet their fate in ecosystems is not fully understood. Here, we review the transport and transformation of metal nanoparticles in the subsurface with emphasis on mechanisms, research techniques, and numerical modeling. Transport can be explained by the Derjaguin–Landau–Verwey–Overbeek theory, the colloid filtration theory, advection–dispersion, Brownian diffusion, interception, gravitational sedimentation, attachment–detachment, straining, blocking and ripening, colloid-facilitated transport, hetero-aggregation, and competitive blocking. Transport research techniques include columns, lysimeters, quartz crystal microbalance, and parallel plate and atomic force microscopy. Metal nanoparticle transformation is characterized by diffuse gradient in thin films and combined microscopy and spectrometry. There are transformation, transport, co-transport, and coupling models. Metal nanoparticles are commonly retained in porous media with small grain sizes, rough surfaces, and surface charges opposite to that of the metal nanoparticles. Transport of metal nanoparticles is favored by colloids and competitive blocking during co-transport. The transformation of metal nanoparticles significantly changes the properties and transport characteristics, which limits the predictions of models.

Oil recovery in geological reservoirs can be enhanced by surfactant flooding, yet this technique is limited by surfactant adsorption on rocks. Here we review the use of nano-silica to decrease surfactant adsorption and to recover more oil, with a focus on surfactant flooding and adsorption, nano-silica properties and development, strategies to reduce surfactant adsorption, and the use of other nanoparticles such as zinc oxide, zirconium oxide, and titanium dioxide. During classical waterflooding, more than 60% of the oil remains trapped in reservoirs due to adsorption of surfactants onto reservoir rocks, which can reach up to 2.84 mg/g. The use of nano-silica reduces surfactant adsorption by 43%, lowers the adsorption density to 1.61 mg/g, and, in turn, improves oil recovery from 4.43 to 9.11%.

Polycyclic aromatic hydrocarbons are ubiquitous occurring in the environment, they originate from various sources such as fossil fuels and combustion products, and some of them display toxic effects. Here, we review polycyclic aromatic hydrocarbons with emphasis on their sources and fate, environmental parameters based on their ratios, toxicity, socioeconomic impact of marine pollution, and polycyclic aromatic hydrocarbons in bivalves of the Back Sea, including Ukraine, Romania, Bulgaria, Turkey, and Russia. We observe that petrogenic pollution dominates in most regions, with phenanthrene being the predominant compound. Elevated polycyclic aromatic hydrocarbon levels were observed near major shipping routes, ports, and industrial zones, particularly along Turkey’s coast, the Constanța area in Romania, and Odessa in Ukraine. Lower contamination levels were recorded in less industrialized areas such as Bulgaria. Seasonal variations indicate higher polycyclic aromatic hydrocarbon concentrations during warmer months, likely influenced by increased recreational and shipping activities. Carcinogenic polycyclic aromatic hydrocarbons accounted for a substantial proportion of total pollutants in some areas, posing risks to marine biota and human health. While western and southern regions exhibit moderate to severe contamination, the eastern Black Sea remains understudied.