This study assesses a plausible correlation between a dust intrusion episode and a daily increase in COVID-19 cases. A surge in COVID-19 cases was observed a few days after a Middle East Dust (MED) event that peaked on 25ᵗʰ April 2020 in southwest Iran. To investigate potential causal factors for the spike in number of cases, cross-correlations between daily combined aerosol optical depths (AODs) and confirmed cases were computed for Khuzestan, Iran. Additionally, atmospheric stability data time series were assessed by covering before, during, and after dust intrusion, producing four statistically clustered distinct city groups. Groups 1 and 2 had different peak lag times of 10 and 4-5 days, respectively. Since there were statistically significant associations between AOD levels and confirmed cases in both groups, dust incursion may have increased population susceptibility to COVID-19 disease. Group 3 was utilized as a control group with neither a significant level of dust incursion during the episodic period nor any significant associations. Group 4 cities, which experienced high dust incursion levels, showed no significant correlation with confirmed case count increases. Random Forest Analysis assessed the influence of wind speed and AOD, showing relative importance of 0.31 and 0.23 on the daily increase percent of confirmed cases, respectively. This study may serve as a reference for better understanding and predicting factors affecting COVID-19 transmission and diffusion routes, focusing on the role of MED intrusions.

Layered double hydroxide (LDH) nanomaterials have recently become immense research area as it is used widely in industries. So, it’s chance of their release into natural environment and risk assessment to nontarget aquatic invertebrate increasing. So, the present study aimed to synthesize and confirm the crystalline formation of Co-Cd-Fe LDHs and Co-Cd-Fe/PbI₂ (LDH) and then to investigate the toxic impact of the two LDH on the adult freshwater snails (Biomphalaia alexandrina). Results showed that Co-Cd-Fe/PbI₂ LDH has more toxic effect to adult Biomphalaria than Co-Cd-Fe LDHs (LC₅₀ was 56.4 and 147.7 mg/L, 72 h of exposure, respectively). The effect of LC₂₅ (117.1 mg/L) of Co-Cd-Fe LDHs exposure on the embryo showed suppression of embryonic development and induced embryo malformation. Also, it showed alterations in the tegmental architectures of the mantle-foot region of B. alexandrina snails as declared in scanning electron micrograph. Also, exposure to this sublethal concentration caused abnormalities in hemocyte shapes and upregulated IL-2 level in soft tissue. In addition, it decreased levels of nonenzymatic reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), caspase-3 activity, and total protein content in significant manner. Glutathione S-transferase (GST) activity was not affected by LDH exposure. It caused histopathological damages in both glands of snails and also caused a genotoxic effect in their cells. The results from the present study indicated that LDH has risk assessment on aquatic B. alexandrina snails and that it can be used as a biological indicator of water pollution with LDH.

Fine particulate matter (PM₂.₅) has been linked to cardiopulmonary disease and systemic effects in humans. However, few studies have investigated the particle bioreactivity in Chinese megacities during haze episodes. The objective of this study was to determine the contributions of chemical components in PM₂.₅ to particle bioreactivity in Chinese megacities during haze episodes. PM₂.₅ samples were collected in 14 megacities across China from 23 December 2013 to 16 January 2014. Average PM₂.₅ concentrations ranged 88.92~199.67 μg/m³. Organic carbon (OC), elemental carbon (EC), anions, and cations per unit of PM₂.₅ were linked to cellular bioreactivity (i.e., reactive oxygen species (ROS) as assessed by dichlorodihydrofluorescein diacetate (DCFH) and inflammation as assessed by interleukin (IL)-6 in A549 cells). The contributions of chemicals in PM₂.₅ to ROS and inflammation were examined by the Pearson correlation coefficient and random forests. These results indicated that OC, Ca²⁺, SO₄²⁻, Cl⁻, F⁻, K⁺, and NO₃⁻ contributed to ROS production, whereas OC, Cl⁻, EC, K⁺, F⁻, Na⁺, and Ca²⁺ contributed to inflammation. In conclusion, PM₂.₅-contained OC and acidic ions are important in regulation of oxidative stress and inflammation during haze episodes. Our findings suggest that severe haze PM₂.₅ events cause deterioration in air quality and may adversely affect human health.

In this study, we simulate the irrigation of tomato plants with arsenic (As)-contaminated water (from 0 to 3.2 mg L⁻¹) and investigate the effect of the application of silicon nanoparticle (Si NPs) in the form of silicon dioxide (0, 250, and 1000 mg L⁻¹) on As uptake and stress. Arsenic concentrations were determined in substrate and plant tissue at three different stratums. Phytotoxicity, As accumulation and translocation, photosynthetic pigments, and antioxidant activity of enzymatic and non-enzymatic compounds were also determined. Our results show that irrigation of tomato plants with As-contaminated water caused As substrate enrichment and As bioaccumulation (roots > leaves > steam), showing that the higher the concentration in irrigation water, the farther As translocated through the different tomato stratums. Additionally, phytotoxicity was observed at low concentrations of As, while tomato yield increased at high concentrations of As. We found that application of Si NPs decreased As translocation, tomato yield, and root biomass. Increased production of photosynthetic pigments and improved enzymatic activity (CAT and APX) suggested tomato plant adaptation at high As concentrations in the presence of Si NPs. Our results reveal likely impacts of As and nanoparticles on tomato production in places where As in groundwater is common and might represent a risk.

This study aimed to identify the specific genes associated with plant growth promotion and cadmium tolerance in three bacteria strains associated with Pennisetum giganteum as well as to determine their biosafety levels in their potential use as biofertilizers for promoting plant growth and phytoremediation activities. The plant growth-promoting (PGP) abilities of Enterobacter cloacae strain RCB980 (A3), Klebsiella pneumonia strain kpa (A4), and Klebsiella sp. strain XT-2 (A7) were determined by a growth promotion trial and through testing for PGP traits such as 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme production, phosphorus solubilization, siderophore synthesis, and indole-3 acetic acid (IAA) production. The genes that potentially contribute to the beneficial activities of these three strains were identified through an analysis of their genomes. To establish the biosafety of the candidate PGPB, a pathological study was undertaken whereby 20 Kunming mice were injected intraperitoneally to study and analyze the effects of the strains on growth and lung paraffin sections of the mice. The strains had no obvious toxicity effect on the tested mice and were therefore not considered as highly virulent strains. These strains are thus considered non-toxic, safe, and highly recommended for use in environmental remediation strategies and agricultural production.

Phenol is widely used in industrial processes and has microbial toxicity. However, the effects of a phenol spill on the microbial community are not clear. The present study explored the changes of bacterial communities in river and fish pond sediments after a phenol spill. The bacterial richness and diversity in river sediments were lower on day 30 (36 days after the spill) than on day 0, while they increased in fish pond sediments. The structures and functions of bacterial communities in both river and fish pond sediments were changed, and a more dramatical variation was detected in fish pond sediments. In river sediments, Proteobacteria, Chloroflexi, Acidobacteria, Bacteroidetes, and Nitrospirae were the major bacterial phyla, and Chloroflexi was enriched. In fish pond sediments, genera Brevibacillus dominated bacterial communities initially, and bacterial composition showed a dramatic change on day 30. Most predicted metabolism functions, as well as genetic information processing functions of translation, replication, and repair, were enhanced in both river and fish pond sediments, while they showed an opposite change trend for xenobiotic degradation function. This work could strengthen our understanding of the effects of phenol spills on sediment bacterial communities in both lotic and lentic ecosystems.

Although several non-thermal plasmas (NTPs) technologies have been widely investigated in air treatment, very few studies have focused on the inactivation mechanism of viruses by NTPs. Due to its efficiency and environmental compatibility, non-thermal plasma could be considered a promising virus-inactivation technology. Plasma is a partly or fully ionized gas including some species (i.e., electrons, free radicals, ions, and neutral molecules) to oxidize pollutants or inactivate harmful organisms. Non-thermal plasmas are made using less energy and have an active electron at a much higher temperature than bulk gas molecules. This review describes NTPs for virus inactivation in indoor air. The different application processes of plasma for microorganism inactivation at both laboratory and pilot-scale was also reviewed This paper reports on recent advances in this exciting area of viral inactivation identifying applications and mechanisms of inactivation, and summarizing the results of the latest experiments in the literature. Moreover, special attention was paid to the mechanism of virus inactivation. Finally, the paper suggests research directions in the field of airborne virus inactivation using non-thermal plasma.

Epidemiological studies have demonstrated that various kinds of urinary element concentrations were different between healthy, prediabetes, and diabetes patients. Meanwhile, many studies have explored the relationship between element concentration and fasting blood glucose (FBG), but the association between joint exposure to co-existing elements and FBG level has not been well understood. The study explored the associations of joint exposure to co-existing urinary elements with FBG level in a cross-sectional design. 275 retired elderly people were recruited from Beijing, China. The questionnaire survey was conducted, and biological samples were collected. The generalized linear model (GLM) and two-phase Bayesian kernel machine regression (BKMR) model were used to perform in-depth association analysis between urinary elements and FBG. The GLM analysis showed that Zn, Sr, and Cd were significantly correlated with the FBG level, under control potential confounding factors. The BKMR analysis demonstrated 8 elements (Zn, Se, Fe, Cr, Ni, Cd, Mn, and Al) had a higher influence on FBG (posterior inclusion probabilities > 0.1). Further intensive analyses result of the BKMR model indicated that the overall estimated exposure of 8 elements was positively correlated with the FBG level and was statistically significant when all creatinine-adjusted element concentrations were at their 65th percentile. Meanwhile, the BKMR analysis showed that Cd and Zn had a statistically significant association with FBG levels when other co-existing elements were controlled at different levels (25th, 50th, or 75th percentile), respectively. The results of the GLM and BKMR model were inconsistent. The BKMR model could flexibly calculate the joint exposure to co-existing elements, evaluate the possible interaction effects and nonlinear correlations. The meaningful conclusions were found that it was difficult to get by traditional methods. This study will provide methodological reference and experimental evidence for the association between joint exposure to co-existing elements and FBG in elderly people.

This paper asymmetrically analyzes the impact of energy consumption and oil price fluctuations on the economic growth of the MENA net oil-exporting and importing nations from 1990 to 2019 using panel nonlinear autoregressive distributed lag (PNARDL) model developed by (Salisu and Isah, Econ Model 66:258–271, 2017). The findings revealed that for the net-oil exporting countries, the impact of nonrenewable energy on economic growth is nonlinear in both terms, where in the both terms, high consumption of nonrenewable energy is influencing economic growth and its low consumption is limiting it. Furthermore, the impact of renewable energy is linear and it is influencing and limiting economic growth in both terms respectively. Moreover, the impact of oil price fluctuations on economic growth is linear in the long run and nonlinear in the short run, where in the long run, increase in it is not influencing economic growth but in the short run, while its decrease has no effect. For the net-oil importing countries, the impact of nonrenewable energy on economic growth is nonlinear in both terms, where in the long run, high consumption of nonrenewable energy is influencing economic growth but in the short run, it is discouraging it; however, in both terms, low consumption of nonrenewable energy has no effect. In addition, in the long run, the impact of renewable energy is nonlinear but linear in the short run; however, none of its impacts is significant in both terms. Also, the impact of oil price fluctuations on economic growth is linear in both terms and in the both terms, it is influencing economic growth. Nonetheless, for all the variables, the impacts are higher in the net-oil exporting countries. Policy recommendations were provided.

Urban green spaces (UGSs) provide various ecosystem services (ESs) that directly and indirectly enhance people’s well-being. However, in the Saudi context, the assessment role of UGSs (such as urban parks and gardens) and their use and accessibility has remained unexplored. This study aims to assess the use and accessibility of five urban parks in the Jeddah megacity of Saudi Arabia from diversified perspectives. Data were collected through a primary survey and questionnaire method using a social preference approach (SPA). Correlation analysis and factor analysis were performed to assess the relationship between activities and services (benefits) provided by urban parks and to examine their most significant benefits. A Kruskal–Wallis (K–S test) test was performed to determine significant differences in the perceived valuations of park benefits. A benefit dominancy index (BDI) was also developed to determine which urban parks provide the most benefit. The findings of the study showed that (i) the urban parks were mostly used for spending time with relatives (partners) and friends, followed by mental refreshment and relaxation, physical activity, and spending time with children; (ii) there are substantial seasonal variations in park visits in the Jeddah megacity; (iii) socio-demographic attributes largely affect the use of urban parks; and (iv) there are also substantial discrepancies between importance and performance related to urban management strategies. Thus, the findings of this study show that city planners and policy makers must focus on the enhancement of UGSs for the well-being of urban citizens.