The bioaerosols present in indoor air play a major role in the transmission of infectious diseases to humans, therefore concern about their exposure is increased recently. In this regard, the present investigation described the preparation of lemongrass essential oil (LGEO) loaded chitosan and cellulose nanofibers composites (CH/CNF) for controlling the indoor air bioaerosol. The evaluation of the inhibitory effect of the composite system on culturable bacteria of the indoor air was done at different sites (air volume from 30 m³ to 80 m³) and in different size fractions of aerosol (<0.25 μm–2.5 μm). The composite system had high encapsulation efficiency (88–91%) and citrals content. A significant reduction in culturable bacteria of aerosol (from 6.23 log CFUm⁻³ to 2.33 log CFUm⁻³) was observed in presence of cellulose nanofibers and chitosan composites. The bacterial strains such as Staphylococcus sp., Bacillus cereus, Bacillus pseudomycoides sp., Pseudomonas otitidis, and Pseudomonas sp. Cf0-3 in bioaerosols were inhibited dominantly due to the diffusion of aroma molecules in indoor air. The results indicate that the interaction of diffused aroma molecule from the composite system with bacterial strains enhanced the production of ROS, resulting in loss of membrane integrity of bacterial cells. Among different size fractions of aerosol, the composite system was more effective in finer size fractions (<0.25 μm) of aerosol due to the interaction of smaller aroma compounds with bacterial cells. The study revealed that LGEO loaded chitosan and cellulose nanofibers composites could be a good option for controlling the culturable bacteria even in small-sized respirable bioaerosol.

Pesticides aid in crop-protection against pests and increase yield. However, the xenobiotic stress exerted by pesticides leads to the deterioration of human and animal health. There is a lacuna in our knowledge about their impact on the ocular surface The present work sheds light on this gap by analysing the deterioration of visual acuity as a consequence of pesticide induced xenobiotic stress and Notch pathway dysregulation.Alteration in the expression of vital components of the notch signalling was analyzed along the visual pathway with special focus on its two terminals-the cornea and the visual cortex, by mimicking the on-field scenario regarding chronic pesticide exposure in experimental murine model (Swiss albino mice; Mus musculus). Various aspects were taken into consideration through visual acuity tests, histological evaluations, culture analyses, wound healing assays, flowcytometric evaluation, fluorescence microscopic studies etc. Complete dysregulation of key players of the Notch signalling pathway was observed in both: cells of the ocular surface as well as those in the murine visual cortex post pesticide exposure, indicating activities relating to cell proliferation, differentiation and wound healing in the pesticide exposed samples. Ultra-microscopic analyses corroborated our findings by revealing the loss of fine neural processes in the visual cortex of the pesticide exposed murine samples, thereby hinting at delayed perception to visual stimuli. In vivo evaluations of the functional capacity of the neuroanatomical structures along the visual pathway also confirmed that pesticide exposure leads to severe damage along the various parts of the visual pathway, right from the ocular surface to the visual cortex.

Urea is one of the most commonly used nitrogen fertilizers in agricultural soil and is easily decomposed by soil urease resulting in ammonium release. The produced ammonium can be volatilized or converted to nitrate, which is susceptible to leaching, leading to groundwater contamination unless used by plants. Hence, it is important to control the release of nitrogen from the urea. Pyroligneous acid inhibited the urease activity and decreased ammonium release up to 80% compared to the control. Amidase including asparaginase and glutaminase is an enzyme that catalyzes hydrolysis of amide group, similar to urease. Therefore, the effect of pyroligneous acid on the inhibition of soil amidase was also tested and the results showed that pyroligneous acid competitively inhibited asparaginase while glutaminase was not inhibited. However, inhibitory effect of pyroligneous acid on asparaginase was negligible compared to the urease. The application of pyroligneous acid with a smaller amount of urea for controlled nitrogen release during Chinese cabbage growth showed that dry biomass and nutrient contents of Chinese cabbage were similar to the case of the conventional urea application. The nitrogen utilization efficiency (NUE) was highest for 33% less amount of urea supply with pyroligneous acid (2.21) compared to conventional treatment (1.81). Consequently, the use of pyroligneous acid with urea enhances nitrogen use efficiency while also protecting environments from non-point source contamination.

Biomass of Java plum (JP) and amaltash (AT) seeds were employed to remove arsenic from synthetic wastewater, cost effectively. The prepared biomasses were characterized by FE-SEM, EDX, FTIR, XRD, and ICP techniques. Experimentation the optimization study has been carried out by using Design-software 6.0.8. Response surface methodology has been applied to design the experiments where we have used three factors and three levels Box-Behnken design (BBD). Arsenic removal ability of bio-sorbents was evaluated and optimized by varying pH, adsorbent dose concentration of arsenic in synthetic wastewater. For 2.5 mg/L arsenic concentration and 80 mg adsorbent dose at pH 8.8 Java plum seeds (JP) based bio-adsorbent removed ∼93% and amaltash seeds (AT) based bio-adsorbent removed ∼91% arsenic from synthetic wastewater. The adsorption behaviour better explained following Freundlich model (R² = 0.99) compared to Temkin model (R² = 0.986) for As (III) ions. The adsorption capacity was 1.45 mg g⁻¹ and 1.42 mg g⁻¹ for JP and AT, respectively after 80 min under optimal set of condition. The adsorption kinetics was explained by either pseudo-first order model or Elovich model.

Stormflow runoff is the most important agent for phosphorus (P) input to reservoirs, as the particulates contained in runoff carry a substantial amount of P. The settling process of particulates affects the P content of water, and the distribution of particulates determines the P distribution in reservoir sediment. An understanding of flood impacts on the transport, transition, and accumulation of P in a reservoir is critical to reservoir management. In this study, water samples before and after flooding and sediment samples after flooding were collected from Biliuhe Reservoir in Northeast China. P content and load in the water and P-fractions and particle sizes of the sediments were analyzed. Results showed that total particulate P (TPP) increased sharply from 1.56 to 26.72 t after flooding, whereas dissolved organic P (DOP) decreased markedly from 3.24 to 1.17 t, which was largely caused by biological uptake directly or indirectly before flooding. Orthophosphate (PO43−) shared a similar trend with TPP, indicating that PO43− could be adsorbed onto settling particulates, helping to reduce the reactive P introduced by flooding. Reservoir sediment showed a fining trend downstream and the clay fraction exhibited an obvious correlation with P-fractions, demonstrating that the distribution of particulate matter determined P distribution in the sediment. This study also found that particulates from the largest tributary (Biliu River) were only minimally transported from its reservoir entrance to the dam because of a longer travel distance, while contrastingly, particulates from a smaller tributary (Bajia River) were maximally carried to the dam because of a shorter distance. Our fundings suggests that surface water in the reservoir should be released prior to flooding in order to mitigate control of P in the water, moreover, it is necessary to strengthen the effectiveness of pollutant control projects at the reservoir entrance of the Bajia River.

Polycyclic aromatic hydrocarbons (PAHs) are the main contaminants of coke oven emissions which can induce serious genetic damage in coke oven workers. Epigenetic alternations play essential roles in the regulation of DNA damage effect of PAHs. Previous studies indicate that H3K79 di-methylation (H3K79me2) is integral in DNA damage repair. However, the potential role of H3K79me2 in DNA damage response (DDR) following PAHs exposure is still unclear. In this study, we recruited 256 male coke oven workers and control workers, and examined H3K79me2 and DNA damage in their peripheral blood lymphocytes (PBLCs). The results showed that global H3K79me2 of coke oven workers was 29.3% less than that of the controls (P < 0.001). The H3K79me2 was negatively correlated with the concentration of urinary 1-hydroxypyrene (1-OHP) (β = -0.235, P < 0.001) and level of genetic damage evaluated by comet assay (βTₐᵢₗ DNA % = -0.313, P < 0.001; βOTM = -0.251, P = 0.008). Consistently, we found that benzo(a)pyrene (BaP) inhibited H3K79me2 in immortalized human bronchial epithelial (HBE) cells in a time-dependent manner. In order to explore the function of H3K79me2 in PAHs DDR, we established histone 3.1/3.3 K79A mutant cells (H3K79 A) to suppress H3K79me2. H3K79 A cells showed more serious DNA damage and decreased cell viability than control cells after BaP treatment. In addition, we also found that the expression of DOT1L, the only methyltransferase in H3K79, was repressed by BaP dose-dependently. DOT1L knockdown resulted in decreased H3K79me2 level and aggravated DNA damage after BaP exposure. This suggests that BaP induces H3K79me2 repression via inhibiting DOT1L expression. In conclusion, these findings indicate that PAH exposure decreases the level of global H3K79me2, which is integral for DNA damage response regulation of PAHs.

This study investigated the polycyclic aromatic hydrocarbons (PAHs) occurrence, and their impact on the microbial community and PAH-degrading genera and genes in the Knysna Estuary of South Africa. The results reveal that the estuary exhibits low PAH levels (114.1–356.0 ng g⁻¹). Ignavibacteriae and Deferribacteres, as well as Proteobacteria and Bacteroidetes, are keystone phyla. Among measured environmental factors, total organic carbon (TOC), nutrients such as nitrite and nitrate, metals as Al, Cr, Cu, Ni, Pb and Zn, and environmental properties (pH and salinity) are primary contributors to structuring the bacterial community assemblage. The abundance of alpha subunit genes of the PAH-ring hydroxylating dioxygenases (PAH-RHDα) of Gram-negative bacteria lies in the range of (2.0–4.2) × 10⁵ copies g⁻¹, while that of Gram-positive bacteria ranges from 3.0 × 10⁵ to 1.3 × 10⁷ copies g⁻¹. The PAH-degrading bacteria account for up to 0.1% of the bacterial community and respond mainly to nitrate, TOC and salinity, while PAHs at low concentration are not significant influencing factors. PAH degraders such as Xanthomonadales, Pseudomonas, and Mycobacterium, which play a central role in PAH-metabolization coupled with other biogeochemical processes (e.g. iron cycling), may contribute to maintaining a healthy estuarine ecosystem. These results are important for developing appropriate utilization and protection strategies for pristine estuaries worldwide.

Using Fe(II) salt as the precipitant in heterotrophic denitrification achieves improved TP removal, and enhancement in denitrification was often observed. This study aimed to obtain a better understanding of Fe(II)-enhanced denitrification with sufficient carbon source supply. Laboratory-scale experiments were conducted in SBRs with or without Fe(II) addition. Remarkably improved TP removal was experienced. TP removal efficiency in Fe(II) adding reactor was 85.8 ± 3.4%; whereas, that in the reactor without Fe(II) addition was 31.1 ± 2.8%. Besides improved TP removal, better TN removal efficiency (94.1 ± 1.1%) were recorded when Fe(II) was added, and that in the reactor without Fe(II) addition was 89 ± 0.8%. The specific denitrification rate were observed increase by 12.6% when Fe(II) was added. Further microbial analyses revealed increases in the abundances of typical denitrifiers (i.e. Niastella, Opitutus, Dechloromonas, Ignavibacterium, Anaeromyxobacter, Pedosphaera, and Myxococcus). Their associated denitrifying genes, narG, nirS, norB, and nosZ, were observed had 14.2%, 19.4%, 21.6%, and 9.9% elevation, respectively. Such enhancement in denitrification shall not be due to nitrate-dependent ferrous oxidation, which prevails in organic-deficient environments. In an environment with a continuous supply of Fe(II) and plenty of carbon sources, a cycle of denitrifying enzyme activity enhancement in the presence of Fe(II) facilitating nitrogen substrate utilization, stimulating denitrifier metabolism and growth, elevating denitrifying genes abundance, and increasing denitrifying enzymes expression were thought to be responsible for the Fe(II)-enhanced heterotrophic denitrification. Fe(II) salt is often a less expensive precipitant and has recently become attractive for TP removal in wastewater. The findings of this study solidify previous observation of enhancement of both TP and TN removal by adding Fe(II) in denitrification, and would be helpful for developing cost-effective pollutant removal processes.

Air pollution, which includes particulate matter (PM), is classified in group 1 as a carcinogen to humans by the International Agency for Research in Cancer. Specifically, PM exposure has been associated with lung cancer in patients living in highly polluted cities. The precise mechanism by which PM is linked to cancer has not been completely described, and the genotoxicity induced by PM exposure plays a relevant role in cell damage. In this review, we aimed to analyze the types of DNA damage and alterations in DNA repair pathways induced by PM exposure, from both epidemiological and toxicological studies, to comprehend the contribution of PM exposure to carcinogenesis. Scientific evidence supports that PM exposure mainly causes oxidative stress by reactive oxygen species (ROS) and the formation of DNA adducts, specifically by polycyclic aromatic hydrocarbons (PAH). PM exposure also induces double-strand breaks (DSBs) and deregulates the expression of some proteins in DNA repair pathways, precisely, base and nucleotide excision repairs and homologous repair. Furthermore, specific polymorphisms of DNA repair genes could lead to an adverse response in subjects exposed to PM. Nevertheless, information about the effects of PM on DNA repair pathways is still limited, and it has not been possible to conclude which pathways are the most affected by exposure to PM or if DNA damage is repaired properly. Therefore, deepening the study of genotoxic damage and alterations of DNA repair pathways is needed for a more precise understanding of the carcinogenic mechanism of PM.

The properties of phosphate in lakes and their ability to cause eutrophication have been well studied; however, the effects of phosphate on the environmental behavior of other substances in lakes have been ignored. Dissolved organic matter (DOM) and heavy metals may coexist with phosphate in lakes. Herein, the mechanisms underlying the influence of phosphate on heavy metals complexation with DOM were investigated using multi-spectroscopic tools. Overall, the amount of DOM-bound Cu(Ⅱ) decreased with the increasing phosphate content. Furthermore, the fluorescence excitation and emission matrix results combined with parallel factor analysis showed that when the Cu(Ⅱ) concentration increased from 0 to 5 mg/L and 50 μM phosphate to the reaction of DOM and copper, the fluorescence intensity of tyrosine (component 1), humic-like (component 2) and tryptophan (component 3) decreased by 36.46%, 57.34%, and 74.70% compared with the treatment with no phosphate addition, respectively. This finding indicates that the binding of different fluorescent components to Cu(Ⅱ) was restricted by phosphate. Furthermore, different functional groups responded differently to Cu(Ⅱ) under different phosphate concentrations. The binding sequence of different functional groups under high concentration of phosphate (phenolic hydroxyl group＞amide (Ⅰ) ＞carbohydrates) was completely opposite to that with no phosphate. These results demonstrated that phosphate could restrict the binding affinity of heavy metals with different fluorescent substances or organic ligands of DOM, suggesting that the comigration of DOM-bound heavy metals in lakes is hindered by phosphate and the risk of heavy metal poisoning in aquatic organisms is therefore diminished.