This paper examines the nexus between the Covid-19 confirmed cases, deaths, meteorological factors, including an air pollutant among the world’s top 10 infected countries, from 1 February 2020 through 30 June 2020, using advanced econometric techniques to address heterogeneity across the nations. The findings of the study suggest that there exists a strong cross-sectional dependence between Covid-19 cases, deaths, and all the meteorological factors for the countries under study. The findings also reveal that a long-term relationship exists between all the meteorological factors. There exists a bi-directional causality running between the Covid-19 cases and all the meteorological factors. With Covid-19 death cases as the dependent variable, there exists bi-directional causality running between the Covid-19 death cases and Covid-19 confirmed cases, air pressure, humidity, and temperature. Temperature and air pressure exhibit a statistically significant and negative impact on the Covid-19 confirmed cases. Air pollutant PM2.5 also exhibits a significant but positive impact on the Covid-19 confirmed cases. Temperature indicates a statistically significant and negative impact on the Covid-19 death cases. At the same time, Covid-19 confirmed cases and air pollutant PM2.5 exhibit a statistically significant and positive impact on the Covid-19 death cases across the ten countries under study. Hence, it is possible to postulate that cool and dry weather conditions with lower temperatures may promote indoor activities and human gatherings (assembling), leading to virus transmission. This study contributes both practically and theoretically to the concerned field of pandemic management. Our results assist in taking appropriate measures in implementing intersectoral policies and actions as necessary in a timely and efficient manner. Causal relations of Meteorological factors and Covid-19 (2 models used in the study)

Active functional groups in biofilms determine the adsorption and desorption of contaminants and nutrients. Epilithic biofilms were characterized in order to understand the association between the chemistry alteration patterns and the surrounding anthropic activities of the Guaporé River watershed. The instrumental analyses included pyrolysis coupled to gas chromatography and mass spectroscopy, spectroscopy in the IR region with attenuated total reflectance, and two-dimensional nuclear magnetic resonance. Spectrometric techniques demonstrated that epilithic biofilms are mainly composed of polysaccharides, nitrogen-containing compounds, lipids, and aromatic and phenolic structures, which have functional groups characteristic of alcohols, esters, ethers, and amides. The polysaccharide levels reflect well the environmental pressures. The chemical composition of epilithic biofilms can be an effective tool for environmental assessment in watercourses, since the different anthropic actions developed in watersheds, mainly agriculture and urban areas, can modify the organic fraction of biofilms.

The socio-economic needs of ancient societies before the onset of the industrial revolution thrived the exploitation of metals, with resultant adverse effects on the chemical signatures of soils. So far, there are no studies that summarize the contamination of soils by metals due to mining and metallurgy before the industrial revolution (c. 1800 century AD). The article presents an overview of soil contamination by metals due to ancient (prehistory up to the end of medieval period) mining and metallurgy, the global distribution of metal exploitations, the effects on soils and lives, as well as their speciation and bioavailability. The study established that the concentrations of Cu, Ag, Pb, Hg, and Zn were substantially higher in the soils affected by ancient mining and metallurgy in comparison to background values, eventually causing harm to ecosystems after centuries without mining and metallurgy. The concentrations of the metals subsequently are bioaccumulated in recent fields. Understanding the persistence, distribution, and bioavailability of the metals is pertinent in selecting suitable remediation techniques for contaminated soils from ancient mining and metallurgy sites. Even after centuries without mining and metallurgy in ancient sites, the long-term fate of metal contaminations in soils is detectable. The still-unsolved question is the level of metals available and releasable from the total content to plants, especially on arable fields of previous mining and metallurgy sites and their surroundings. Contemporary effects of past mining and metallurgy on contamination of soils provide relevant information on the current and future implications of recent metalliferous activities.

The presence of beach litter along the coast is due to the indirect input by waves, wind, rivers and currents and to the direct deposition by beach users. This study, conducted in Sardinia (Western Mediterranean Sea), aims to quantify and characterize beach litter all around the island and to suggest the main sources of impact. Five monitoring campaigns (autumn 2013; spring 2014; autumn 2015; spring 2016; autumn 2016) were conducted considering 3 “exposed” and 4 “sheltered” beaches by means of 33.3-m linear transects in which all “macroscopic” items (> 5 mm) were collected. “Micro” litter (< 5 mm) sampling was performed in 6 beaches through 10-m linear transects. For both sampling designs, abundance and litter typologies were assessed following the protocols of the Marine Strategy Framework Directive (MSFD) and BASEMAN project. Repeated measures permutational analysis of variance was performed to detect any difference in abundance and composition of marine litter according to season, wind exposure and site. Exposure was the factor that better explains the distribution of litter: higher values were found on the “exposed” (E) sites with respect to the “sheltered” (S) ones, both for macroscopic (E: 1696.56 ± 219.25 items/100 m; S: 420.5 ± 74.73 items/100 m) and micro litter (E: 7990.67 ± 2319.44 items/10 m; S: 111.78 ± 25.91 items/10 m). All the 8 typologies were recorded, and litter composition significantly varied according to exposure and site over time. This work provides key information about litter presence and sources, useful to suggest possible mitigation measures.

This study explores the symmetric and asymmetric effects of physical infrastructure on energy consumption, economic growth, and air pollution of Pakistan over the period 1990–2019. The ARDL results for the energy consumption model suggest that aircraft carriers (ACC) and road infrastructure foster energy consumption in the short term. For the growth model, the impact of trade is negative and significant in both short run and long run. The results for environmental pollution model suggest that information communication technology (ICT) is positively associated with CO2 emissions, whereas trade is negatively associated with emissions in the short and long run. The road has a positive impact on CO2 emissions while ACC has a negative impact in the long run. The nonlinear ARDL results reveal that negative component of ICT negatively influences energy consumption, while positive component has insignificant impact. Similarly, ACC, road, and trade also exhibit asymmetric effects. ICT has a significantly negative impact on economic growth. Finally, the positive shock to road has a significantly positive impact on pollution but the negative shock has no impact. Additionally, the coefficient of ACC and trade also infer asymmetries in pollution model. The results offer important policy implications for achieving high growth and better environmental quality in Pakistan.

In bioaccumulation studies, sample devitalization through acid washing or oven drying is commonly applied to enhance the element accumulation efficiency of moss sample. Such aspect, however, has never been considered in biomonitoring surveys using lichens. In this study, the trace element accumulation performance of living (L) and dead (D) samples of the lichen Pseudevernia furfuracea was compared by a side-by-side transplanting at 40 sites in a large, mixed land use area of NE Italy for 8 weeks. Devitalization was achieved without any physico-chemical treatments, by storing lichen samples in a dark cool room for 18 months. Health status of lichens was assessed before and after the sample exposure by chlorophyll fluorescence emission. Although elemental analysis of the two exposed sample sets revealed a similar trace element pollution scenario, the content of 13 out of the 24 selected elements was higher in D samples. By expressing results as exposed-to-unexposed (EU) ratio, D samples show a higher bioaccumulation signal in 80% of transplant sites for Al, Ca, Fe, Hg, Pb and Ti. Overall, the health status of lichen samples might lead to interpretational discrepancies when EU ratio is classified according to the recently proposed bioaccumulation scale.

A known relationship exists between high radon concentrations and lung cancer, and therefore, the indoor radon quantification is important, and it is beneficial to have a model to estimate indoor concentration. The work is focused on the development of an INDORAD (INDOor RAdon Dynamic) model for estimation of indoor radon dynamics, with time-dependent meteorological parameters and adjustable soil and building properties being considered. This model is based on a systemic approach, where the flows of material between compartments are considered, without a spatial resolution. This approach allowed to simplify the mathematical processing and enabled to consider together all known sources of indoor radon. The developed model was put in use in a laboratory building where soil constitutes major source of radon. The results (radon concentrations) from the model were compared to an existing data set from Saelices el Chico in a soil with high concentration of ²²⁶Ra. The outcome of the validation implies that INDORAD could predict radon concentrations satisfactorily. Suggestions for future updates of the model to improve indoor radon estimations are provided.

Sustainable solutions are investigated to reduce the environmental damage caused by greenhouse gases and CO₂ emissions. Cement is a construction material responsible for greenhouse gases and CO₂ emissions. Thus, CO₂ emissions are reduced by using replacement materials such as rice husk ash instead of cement. This study investigated the durability and mechanical properties of lightweight and high-performance, sustainable cement-based composites. A foaming agent was used to reduce the unit weight of the mixtures. Also, pumice powder (PP) and rice husk ash (RHA) were used to improve cement-based composites’ durability and mechanical properties. The density of mixtures varies between 1666 and 2205 kg/m³. The early age strength of the mixes using 12.5% RHA has increased. The mixtures’ compressive strength (91 days) with 25% RHA and 50% PP was 46.6 MPa. As the PP content of mixes increased, drying shrinkage values increased. Expansions decrease as the initial compressive strength increases in mixtures exposed to sulfate. As RHA and PP’s ratio increased, weight loss decreased in mixes exposed to HCl, while weight loss increased in mixes exposed to H₂SO₄. It was determined that the content of CH(OH)₂ is important in mixes exposed to HCl and impermeability is important in mixes exposed to H₂SO₄. It has been observed that the initial compressive strength is also important in mixes exposed to the freeze-thaw effect. As the foam content of the mixes increased, the compressive strength decreased, while the drying shrinkage increased. As a result, using up to 25% RHA has increased the performance of cement-based composites.

Onosma bracteata Wall. (Boraginaceae), commonly known as “gaozaban” is a highly valuable medicinal herb, useful in the treatment of body swellings, abdominal pain, eye-related problems, fever, and urinary calculi. The present study was performed to investigate the antioxidant properties of extract/fractions, viz. ethanol (Obeth) extract, hexane (Obhex) fraction, chloroform (Obcl) fraction, ethyl acetate (Obea) fraction, butanol (Obbu) fraction, and aqueous (Obaq) fraction isolated from O. bracteata. Obea fraction showed stronger free radical quenching ability in various antioxidant assays, as compared to the other fractions. Obea fraction with effective free radical-scavenging properties was further evaluated for the antiproliferative activity against human osteosarcoma MG-63, human neuroblastoma IMR-32, and human lung cancer A549 cell lines using MTT assay. Obea fraction showed strong cytotoxicity with GI₅₀ value of 88.56, 101.61, and 112.7 μg/ml towards MG-63, IMR-32, and A549 cells respectively. Mechanistic studies revealed that Obea fraction in osteosarcoma MG-63 cells increased reactive oxygen species (ROS) level and reduced mitochondrial membrane potential. In the presence of Obea, the cells were found to be arrested in the G₀/G₁ phase in a dose-dependent manner which is also confirmed by the enhancement in the early apoptotic cell population in flow cytometer analysis. Western blotting demonstrated the decrease in expression of p-NFκB, COX-2, p-Akt, and Bcl-xL, whereas upregulation was observed in the expression of GSK-3β, p53, caspase-3, and caspase-9 proteins. RT-qPCR studies revealed downregulation of Bcl-2, cyclin E, CDK2, and mortalin gene expression and upregulation in the expression of p53 genes. The antioxidant and cytotoxic potential of Obea was attributed to the presence of catechin, kaempferol, onosmin A, and epicatechin, as revealed by HPLC analysis. This is the first report regarding the antiproliferative potential of O. bracteata against osteosarcoma.

The present study aims to analyze the influence of stock market and financial institution development on carbon emissions by incorporating the role of renewable energy consumption and foreign direct investment in the function of carbon emissions on G20 member countries from 1981–217. Further, the empirical analysis is carried out on the full sample and sub-samples of developed and developing economies by employing panel econometric techniques. The findings confirm that the stock market development index reduces carbon emissions in the full sample and developed countries while increases carbon emissions in developing countries. However, the index of financial institution development increases carbon emissions in the full sample and developed countries but effect is found insignificant in the case of developing economies. The renewable energy consumption reduces the level of environmental degradation across the panels. Similarly, foreign direct investment increases environmental quality in the full sample and emerging economies while impede environmental quality in the developed economies. On the basis of empirical results, this study recommends policy implications.