Stone crushing processes release particulates and associated noxious substances in our surroundings that are continuously destructing environmental conditions and ecosystem health. Morpho-anatomical changes in some medicinally important native species (Aerva javanica, Calotropis procera, Digera muricata, Euphorbia prostrata, Euploca strigosa, and Peganum harmala) exposed to heavy dust pollution were evaluated. These species selected on the basis of their ubiquitous distribution in the area. Two sites were selected in the Kirana Hills, Sargodha, one near stone crushers within 500-m radius (polluted) and the other 4 km away from the crushers (control) varying significantly in amount of dust particles received. A decrease in plant height of all species from dust-polluted sites was observed. Reduction in height was more prominent in species like C. procera and D. muricata. Stem sclerification increased in C. procera and E. prostrata from the polluted site that is an indication of better tolerance to dust pollution. C. procera showed increased stem and leaf epidermis, stem sclerenchyma, and stem vascular bundles, which can increase resistance to dust pollution. E. strigosa was the most sensitive species in which all morpho-anatomical factors decreased. Survival of plant species depended on specific structural modifications in dermal, mechanical, parenchymatous, and vascular tissue. Overall, dust pollution severely affected plant morphological and micro-morphological traits, but the response of selected species to dust pollution was variable. It is concluded that stem and leaf anatomical traits like size of dermal and storage tissue thickness and stomatal density are good indicators for biomonitoring of dust pollution.

Several studies have previously reported that nanomaterial uptake and toxicity in plants are species dependent. However, the differences between photosynthetic pathways, C3 and C4, following nanomaterial exposure are poorly understood. In the current work, wheat and rice, two C3 pathway species are compared to amaranth and maize, which utilize the C4 photosynthetic mechanism. These plants were cultured in soils which were spiked with CuO, Ag, TiO₂, MWCNT, and FLG nanomaterials. Overall, the C4 plant exhibited higher resilience to NM stress than C3 plants. In particular, significant differences were observed in chlorophyll contents with rice returning a 40.9–54.2% decrease compared to 3.5–15.1% for maize. Fv/Fm levels were significantly reduced by up to 51% in rice whereas no significant reductions were observed in amaranth and maize. Furthermore, NM uptake in the C3 species was greater than that in C4 plants, a trend that was also seen in metal concentration. TEM results showed that CuO NPs altered the chloroplast thylakoid structure in rice leaves and a large number of CuO NPs were observed in the vascular sheath cells. In contrast, there were no significant changes in the chloroplasts in the vascular sheath and no significant CuO NPs were found in maize leaves. This study was the first to systematically characterize the effect of metal and carbon-based nanomaterials in soil on C3 and C4 plants, providing a new perspective for understanding the impact of nanomaterials on plants.

Coagulation and flocculation are two of the steps in the water treatment process in which chemical coagulants based on iron salts or aluminum are used. In order to replace the aluminum or to reduce the concentration of the metal, several natural alternatives to assist in the coagulation/flocculation process have been evaluated, including the use of Abelmoschus escuentus Moench (okra) as a flocculating agent. To determine the degradation time of the okra solution, spectral measurements were performed on the UV–Vis region. The coagulation/flocculation tests were carried out in a jar test equipment, using aluminum polychoride as a coagulant, 1-mgL⁻¹ okra solution as a flocculation aid, and the alkalinizing hydroxide of calcium. Through the spectral measurements and the test in the jar test, it was possible to verify that the solution of the okra remains stable only until the time of 24 h, and after this time, begins the degradation process of the constituents of the okra that promote the flocculation of it. In addition, satisfactory results were obtained in the treatment of water in 24 h, allowing the use of okra as flocculation aid and aluminum polychloride coagulant, as in effluent color removal, with an efficiency of 91 to 96%, and organic matter removal, with an efficiency of 92 to 93.5%.

More and more people make opinions on air quality on social media, as science develops and the seriousness of air quality issues. Studies on sentiment analysis keyed to this kind of public opinions will do help in the introduction and perfection of policy of air quality. The evaluation of opinions sentiment is still a hard point in at this stage. There are only a few researches about the factors of the value of opinions sentiment. This article uses opinions related to air quality from Sina Weibo (Chinese Twitter) users, by online questionnaire surveys, and studies the results of opinions sentiment value about air quality in different groups, aiming at doing a research on the evaluation influence factors of opinions sentiment value on air quality. Furthermore, we came up with a solution synthesizing the influential level to calculate opinions sentiment value. We found amounts of respondents had a negative attitude to the opinions. We can now say with some confidence that education is the most significant influence factor on the public to tell the degree of sentiment level of air quality opinions. The sentiment calculation method where we come up could reduce the one-sidedness of different individuals’ evaluations of the same opinion to some extent. The research could be reference for air quality management from the perspective of public opinion sentiment analysis.

Microplastics (MP) as emerging persistent pollutants were found in raw and drinking water worldwide. Since different methods were used, there is an urgent need for harmonized protocols for sampling, sample preparation, and analysis. In this study, a holistic and validated analytical workflow for MP analysis in aqueous matrices down to 5 μm is presented. For sampling of several cubic meters of water, an easily portable filter cascade unit with different pore sizes (100–20–5 μm) was developed and successfully applied for the sampling of three processed drinking waters, two tap waters and one groundwater. The size distribution and polymer types of MP were determined using a two-step semi-automated Raman microspectroscopy analysis. For quality control, comprehensive process blanks were considered at all times and a recovery test yielded an overall recovery of 81%. The average concentration of identified MP was 66 ± 76 MP/m³ ranging from 1 MP/m³ to 197 MP/m³. All found concentrations were below the limit of quantitation (LOQ) of 1880 MP/m³. The majority consisted of PE (86% ± 111%) while comparatively low numbers of PET (10% ± 25%), PP (3% ± 6%), and PA (1% ± 4%) were found. 79% of all particles were smaller than 20 μm. In summary, this study presents the application of a workflow for sampling and analysis of MP down to 5 μm with first results of no significant contamination in drinking water and groundwater.

The amount of plastics from waste electric and electronic equipment (WEEE) has enormously increased nowadays, due to the rapid expansion and consumption of electronic devices and their short lifespan. This, in combination with their non-biodegradability, led to the need to explore environmentally friendly solutions for their safe disposal. One main obstacle when recycling plastics from WEEE is that they usually comprise harmful additives such as brominated flame retardants (BFRs) that need to be removed before or during their recycling. This paper reviews existing techniques for the recycling of plastics from WEEE and focuses specifically on the advantages, disadvantages, and challenges of pyrolysis as an environmentally friendly method for the production of value-added materials (monomers, hydrocarbons, phenols, etc.). Current technological trends available for the recycling of plastics containing brominated flame retardants are reviewed in an attempt to provide insights for future research on the sustainable management of plastics from WEEE. Emphasis is given on conventional pyrolysis, where a pretreatment step for the debromination of products is applied. This is required since brominated compounds treated at high temperatures may result in the production of harmful to health compounds such as dioxins. All current pretreatment methods (solvent extraction, supercritical fluid technology, etc.) are presented and compared in detail. Co-pyrolysis is also investigated, as it seems to be a very interesting approach, since no catalysts or solvents are used, and at the same time, more plastic wastes can be consumed as feedstock. Furthermore, catalytic pyrolysis along with key parameters, such as the type of the catalyst or pyrolysis temperature, are fully analyzed. Catalysts affect the products’ distribution and enhance the removal of bromine from pyrolysis oils. Finally, an emerging technique, that of microwave-assisted pyrolysis, is also highlighted, as it offers many advantages over conventional pyrolysis. Of course, there are some impediments, such as the operational costs or other difficulties as regards the industrial implementation of the mentioned techniques that need to be overcome through future works.

China is a large economy with unbalanced economic growth throughout different regions, posing a great challenge to allocating energy saving and carbon emissions reduction responsibilities. This paper applies the multi-regional input-output tables of China in 2007 and 2012 to evaluate the status of embodied energy consumption. The embodied energy transfer of eight regions in China is analyzed based on a demand-side perspective. Furthermore, the driving factors of embodied energy changes and the inequality at a regional level are explored via a structural decomposition analysis, which provides references for promoting regional energy development and adjusting the industrial layout. The results indicate that China’s total embodied energy consumption increased from 2.06 billion tons of standard coal equivalent (tce) in 2007 to 3.46 billion tce in 2012. Specifically, embodied energy consumption is concentrated in the Central regions, consuming 710 million tce in 2012. In addition, a large proportion of energy produced in all regions is consumed locally, while the amount of transferred embodied energy is widespread across different regions. The economic scale is the primary driving factor of embodied energy consumption changes, and technological development has a noticeable effect on restraining energy consumption. Regarding the structural effect, significant differences exist in different regions and end-use sectors. In conclusion, the regional development policies aiming to optimize the industrial structure and strengthen energy technology improvement in dual-circulation development patterns are proposed.

The widespread epidemic of the COVID-19 in developed countries such as Europe and the USA has sparked many speculations. What factors caused the rapid early pandemic of the COVID-19 in developed countries is the main goal of this study. We collected the main disease indicators and various environmental and economic factors in 61 countries around the world. Our results show that the number of cases is positively correlated with the country’s GDP. We further analyzed the factors related to the spread of the disease. They indicate a strong positive correlation between the total patient numbers and the number of airline passengers, with an r value of 0.80. There is also a positive correlation between the number of car ownership and the total patient, with an r value of 0.35. Both the flight passengers and car ownership contribute 66% to the number of total patients. The total death numbers and the number of airline passengers are positively correlated, with an r value of 0.71. A positive correlation between the number of car ownership and the total deaths is with an r value of 0.42. The total contribution of both the flight passengers and car ownership to the number of total deaths is 57%. Our conclusion is that the main cause of the coronavirus pandemic in developed countries is related to the transportation. In other words, the number of travelers determined the early coronavirus pandemic. Therefore, it is necessary to strengthen restrictions and screening of passengers at airports, especially international airports.

In this research work, the productivity, energy, exergy, and economic and enviro-economic performance in crushed gravel sand heat storage and biomass evaporator-assisted solar still (CGS-BSS) have been investigated and compared the results with conventional solar still (CSS) under the similar climatic conditions of Coimbatore City during the year 2019. The heat accumulated in crushed gravel sand and biomass evaporator have been used to preheat the inlet saline water and air vapor before entering into the solar still. This results in enhanced air vapor mixture temperature and evaporative heat transfer rate of CGS-BSS significantly. The productivity, energy, and exergy efficiencies in CGS-BSS were improved by 34.6%, 34.4%, and 35%, respectively when compared to CSS. In economic analysis, the payback period (PBP) in both CGS-BSS and CSS was estimated to be about 4.7 months and 3.9 months, respectively. Furthermore, in enviro-economic analysis, the CO₂ emission estimated in CGS-BSS and CSS was about 16.63 tons and 8.18 tons, respectively during its lifetime of 10 years.

Some studies have shown that maternal exposure to perfluoroalkyl substances (PFASs) may be associated with early attention deficit hyperactivity disorder (ADHD) in children. The purpose of this systematic review and meta-analysis is to verify this association by reviewing existing studies and to provide a strong basis for preventing ADHD. The researchers searched electronic databases such as PubMed, Science Direct, Scopus, Google Scholar, Web of Science, and Embase for all studies published before October 2020. Finally, we included nine articles for analysis. Our meta-analysis showed that maternal exposure to PFASs was not significantly associated with the prevalence rate of early childhood ADHD (perfluorooctanoic acid (PFOA), odds ratio (OR) = 1.00, 95% confidence interval (95% CI) = 0.75–1.25; perfluorooctane sulfonate (PFOS), OR = 1.01, 95% CI = 0.88–1.14; perfluorohexane sulfonate (PFHxS), OR = 1.08, 95% CI = 0.80–1.09; perfluorononanoic acid (PFNA), OR = 1.13, 95% CI = 0.99–1.28; perfluorodecanoic acid (PFDA), OR = 1.23, 95% CI = 0.15–2.32). Due to significant heterogeneity, we subsequently performed subgroup analysis and sensitivity analysis. Through subgroup analysis, we found that PFOS concentration of children’s blood and the prevalence rate of early childhood ADHD were statistically positively correlated, and there was also a positive correlation between PFOS exposure and the prevalence rate of early childhood ADHD in the America. Moreover, there was also a statistically positive correlation between PFNA concentration in maternal blood and the prevalence rate of early childhood ADHD. Sensitivity analysis showed that the final results did not change much, the sensitivity was low, and the results were relatively stable. In conclusion, a causal relationship between maternal PFASs exposure and ADHD in children was unlikely. Among them, PFOS, PFNA, and ADHD might have positive associations worthy of further investigation.