At the end of December 2019, the rapid spread of the COVID-19 (SARS-CoV-2) disease and, subsequently, deaths around the world, lead to the declaration of the pandemic situation in the world. At the ...beginning of the epidemic, much attention is paid to person-to-person transmission, disinfection of virus-contaminated surfaces, and social distancing. However, there is much debate about the routes of disease transmission, including airborne transmission, so it is important to elucidate the exact route of transmission of the COVID-19 disease. To this end, the first systematic review study was conducted to comprehensively search all databases to collect studies on airborne transmission of SARS-CoV-2 in indoor air environments. In total, 14 relevant and eligible studies were included. Based on the findings, there is a great possibility of airborne transmission of SARS-CoV-2 in indoor air environments. Therefore, some procedures are presented such as improving ventilation, especially in hospitals and crowded places, and observing the interpersonal distance of more than 2 m so that experts in indoor air quality consider them to improve the indoor air environments. Finally, in addition to the recommendations of the centers and official authorities such as hand washing and observing social distancing, the route of air transmission should also be considered to further protect health personnel, patients in hospitals, and the public in other Public Buildings.
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•The SR was conducted to compile studies on airborne transmission of virus in indoor air.•In total, 14 relevant and eligible studies were included.•There is a great possibility of airborne transmission of SARS-CoV-2 in indoor air.•Improving ventilation is essential, especially in hospitals and crowded places.
The advanced oxidation processes (AOPs), as an alternative technology to eliminate pesticides from aqueous environments, consist of several groups of technologies that have been used with high ...efficiency in the treatment of water and wastewater in recent decades. A systematic review of the scientific literature to evaluate the most common advanced oxidation processes (AOPs) for the removal of organophosphorus pesticides in aqueous matrices is addressed in this study. Meta-analysis is also performed to provide a precise and robust summary estimate after a systematic and rigorous integration of the available evidence. In the current study, 9 sub-groups of AOPs were reviewed, such as electrochemical, UV/H2O2 photolysis, photocatalysis, Fenton-type, plasma, gamma irradiation, sulfate-based catalyst, sonolysis and ozonation technology for organophosphorus pesticides degradation. The random effects model was used to estimate the pooled measurements and 95 % confidence intervals (95 % CI). In total, six studies were included in this review. All studies, except one, used the photocatalytic process as AOP. The average pooled percentage of AOP for pesticide degradation was 66.8 (95 % CI: 58.1–75.6). In addition, the most studied pesticides are chlorpyrifos and diazinon which, according to the results of the meta-analysis, the photocatalytic process has the highest efficiency of diazinon elimination with an average percentage of 79.2 (95 % CI: 76.8–81.5).
•73.77 and 74.75% of MNZ was adsorbed and degraded, respectively, from real wastewater.•The maximum adsorption capacity of Fe3O4@AC MNPs was 56.18 mg/g.•Fe3O4@AC MNPs are easily separated from ...wastewater by applying an external magnet.•Fe3O4@AC MNPs are found to be efficient and stable for four repeated cycles.•The toxicity of the treated effluent was reduced after treatment with both processes.
Metronidazole (MNZ), widely used to treat human bacterial infections, enters surface water and groundwater through sewage effluent that endangers the aqueous environment. In this study, MNZ is removed from real and synthetic wastewater through adsorption and heterogeneous Fenton processes. The Fe3O4 magnetic-activated carbon (AC) nanocomposite (Fe3O4@AC) was synthesized by coprecipitation and characterized by Fourier transform infrared spectroscopy, Field emission scanning electron microscope, Energy dispersive spectroscopy, Brunauer–Emmett–Teller, X-ray powder diffraction and Vibrating sample magnetometer analyzes. MNZ removal efficiency was studied under the influence of several parameters such as pH (3–11), Fe3O4@AC dose (0.1–1 g/L), H2O2 concentration (5–30 mmol/L), initial MNZ concentration (5–30 mg/L), contact time (5–60 min) and temperature (20–60 °C). Bioassay of treated effluents was evaluated by the germination index. Fe3O4@AC was synthesized with high magnetic strength (43.48 emu/g) and large surface area (210.95 m2/g) at nanoscale with a pseudo spherical structure. The maximum MNZ removal efficiency from real and synthetic wastewater by adsorption was 73.77% and 97.6% at pH 7, respectively; whereas, 74.75% and 98.03% at pH 5, respectively, was obtained by the heterogeneous Fenton process. MNZ adsorption is an exothermic process, it follows pseudo-second order kinetics, Langmuir and Freundlich isotherms. Whilst, MNZ oxidation follows pseudo-first order kinetics. Finally, the MNZ removal efficiency during the recovery and regeneration of Fe3O4@AC nanocomposite in the adsorption and heterogeneous Fenton processes was 86.88% and 78.34%, respectively. Bioassay results showed significant reductions in effluent toxicity after treatment with both processes. Clearly, the Fe3O4@AC nanocomposite produced a high efficiency in the treatment of wastewater containing antibiotics.
Chitosan (CS), synthesized from chitin chemically extracted from shrimp shells, was used for the synthesis of magnetic chitosan nanoparticles (Fe
3
O
4
-CSN), which makes the adsorbent easier to ...separate. Fe
3
O
4
-CSN was used for the removal of toxic metals such as vanadium (V(V)) and palladium (Pd(II)) ions from aqueous solutions. Influencing factors on the adsorption process such as pH, contact time, adsorbent dosage, and agitation speed were investigated. A competitive adsorption of V(V) and Pd(II) ions for the active sites was also studied. The monolayer maximum adsorption capacities (
Q
m
) of 186.6 and 192.3 mg/g were obtained for V(V) and Pd(II) ions, respectively. The pseudo-second-order equation gave the best fit for the kinetic data, implying that chemisorption was the determining step. Freundlich model yielded a much better fit than the other adsorption models assessed (Langmuir, Temkin and Dubinin-Radushkevich). Thus, the adsorption of V(V) and Pd(II) ions onto Fe
3
O
4
-CSN is a combination of physical and chemical adsorption, as based on the kinetics and equilibrium study. Generally, physical adsorption is the mechanism that governs the system, while chemical adsorption is the slowest adsorption step that takes place. Thermodynamic studies displayed that the adsorption process was exothermic and spontaneous. Removal efficiencies of 99.9% for V(V) and 92.3% for Pd(II) ions were achieved, implying that Fe
3
O
4
-CSN adsorbent had an excellent ability for the removal of the metal ions from real industrial wastewaters without remarkable matrix effect.
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This study represents the first application of Fe-citrate-based photo-Fenton chemistry for the degradation of chlorpyrifos (CPF) spiked into agricultural runoff, and its phytotoxicity assessment. The ...effects of the initial CPF concentration, time and ratio of Fe-citrate/H
O
on CPF removal during the photo-Fenton reaction were investigated and modeled with analysis of variance using R software by the response-surface methodology package. According to the stationary point in original units, the optimal condition for 70.00% CPF removal was as follows: CPF = 2.5 mg L
(0.0), time = 48.0 min (0.585) and Fe-citrate/H
O
= 0.075 (0.539). Beside running the system at near-neutral pH, another strength of this study is related to the treatment of agricultural runoff contaminated with CPF with a raceway pond reactor, which has the advantages of simplicity of the facilities and procedures, as well as the possibility of using sunlight more efficiently in the field of applications. Finally, untreated and treated agriculture runoffs were used as irrigation to determine their phytotoxic effects on seed germination of cress (Lepidium sativum). Solar photo-Fenton treatment greatly reduced phytotoxicity of agriculture runoff and showed the highest germination percentage (70%) compared to both raw agricultural runoff (60%) and untreated CPF-spiked runoff (35%).
Hazardous organic compounds such as benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene (known as BTEX) found at work and at home can cause adverse health effects of human beings ...throughout their lives. Biological monitoring, an exposure assessment method, considers all exposed organic and non-organic compounds. Our goal was to perform a systematic review and a statistical analysis (meta-analysis) of peer-reviewed publications to assess urinary concentrations of BTEX biomarkers in both occupationally-exposed population and the general population. Several major electronic databases, including Scopus, Embase, Medline, Web of Science, and Google scholar (grey literature), were searched for biomonitoring studies of BTEX. Overall, 33 studies met the eligible criteria for the systematic review and six met the full inclusion criteria for meta-analysis. For meta-analysis, we included studies in which unmetabolized BTEX compounds were measured in urine samples. Due to insufficient data, studies that measured BTEX metabolites in urine samples and unmetabolized BTEX compounds in blood samples were excluded from the meta-analysis but were analyzed in the qualitative synthesis. Most studies showed increased urinary concentrations of BTEX in exposed individuals (mainly workers) compared to unexposed individuals. The results showed that the highest total BTEX concentrations were recorded in painters and policemen. This study showed that the undoubted associations between lifestyle and environmental factors and urinary levels of BTEX or its metabolites have not yet been confirmed in current biomonitoring studies. This is attributed to the few studies reported in this research area, the lack of homogeneous information, and the disagreement in the published results of the studies.
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•Diclofenac (DCF) is widely used to control pain and inflammatory disorders.•The first systematic review on the impacts of DCF side effects was conducted.•A literature search led to ...the identification of 14,862 results, 68 of which met our criteria.•There is a strong relationship between OS and DCF-induced DNA damage.•There is limited evidence of association between DCF and potential for estrogenicity.
Diclofenac (DCF) is a common non-steroidal anti-inflammatory drug (NSAID) that is widely used to control pain and inflammation. There has been much debate about detrimental effects of micro-pollutant such as DCF in non-target organisms. Therefore, the present systematic review (SR) evaluates the possible oxidative stress (OS) and DNA damage induced in DCF-exposed non-target organisms in aquatic environment. A systematic search was conducted in five international literature databases from 1970 to 2021. A comprehensive literature search led to the identification of 14,862 hits, 68 of which met our inclusion criteria. These studies encompassed a wide range of biological endpoints, including OS, DNA damage, cyto-genotoxicity, apoptosis, and estrogenicity potential in non-target organisms. The time, route and types of exposure to DCF was evaluated. There is a strong relationship between DCF exposure and OS, cyto-genotoxicity and DNA damage. Furthermore, there is limited evidence for estrogenic potential of DCF. According to the results of the studies considered in this work, it can be concluded that there is definitive evidence of DCF-induced OS, cyto-genotoxicity and DNA damage on the various types of non-target organisms due to the chronic exposure to DCF. The biomarkers were used to assess adverse consequences and could be used as an early warning signal for environmental monitoring of the presence of pharmaceuticals in aquatic environments. Due to the definitive evidence provided for adverse effects of DCF and multimodel mechanisms of action, it is essential to take a degree of caution to use the DCF and develop the advanced treatment technologies to prevent the release of this type of contaminant to aquatic environments.
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•Activated carbons (ACs) were synthesized from DVDs and CDs wastes as precursor.•CNTs coated on the surface of the as-prepared ACs from CDs and DVDs.•The CNTs/CDsAC and CNTs/DVDsAC ...adsorbents were tested for the adsorption of AO7.•Influential parameters, kinetics, equilibrium and reusability were studied.
The purpose of the present work was to prepare activated carbon (AC) from low-cost wastes, such as digital versatile discs (DVDs) and compact discs (CDs), coated with carbon nanotubes (CNTs) for adsorption of Acid Orange 7 (AO7) from dye-containing solutions. The surface morphology of the activated carbons from DVDs (DVDsAC), CDs (CDsAC), CNTs, CNTs/DVDsAC and CNTs/CDsAC was determined by XRD and SEM techniques. SEM micrographs of adsorbents clearly show a heterogeneous porous surface with irregular pores in the structure of the activated carbons. Results showed that CNTs/DVDsAC (30.3mg/g) and CNTs/CDsAC (32.8mg/g), in comparison with DVDsAC (15.1mg/g) and CDsAC (9.9mg/g), were more efficient adsorbents for the adsorption of AO7. The dye adsorption amount (qe) increases with a reduction in the solution pH, adsorbent dosage and an increase in the initial concentration of AO7 for these two more efficient adsorbents. Pseudo-second order model and Langmuir isotherm fitted with the experimental data. The spontaneous and endothermic processes were analyzed by the thermodynamic studies for the adsorption of AO7. The negative values of ΔG, and the positive values of ΔH and ΔS parameters indicate that the adsorption of AO7 onto CNTs/CDsAC and CNTs/DVDsAC was spontaneous and endothermic, respectively.
The removal of low concentration of chlorbromuron herbicide in aqueous systems was carried out by electro-Fenton process comprised of three-electrode divided and undivided cell with a reticulated ...vitreous carbon cathode and platinum anode. The electro-Fenton was also carried out in a two-electrode undivided cell in which ferrous ion forms from a sacrificial iron anode. It was observed that the total organic carbon (TOC) removal efficiency was influenced by the cell voltage, the pH of the solution and initial herbicide concentration during the electro-Fenton treatment with a stainless steel anode. The Fe
2+/Fe
3+ activity in the Fenton chemistry (regardless if it is hydroxyl radical or ferryl ion) was improved by the electrochemical catalysis leading to a TOC analysis below the detection limit (0.2
mg
l
−1) corresponding to a TOC removal over 98%. It was found that TOC removal during chlorbromuron degradation followed apparent first order kinetics. The rate constant was increased by decreasing the initial concentration of chlorbromuron.
Whereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development, the relationship ...between thyroid hormone levels and human cancer is a controversial issue. It has been reported that hypothyroidism might be a possible risk factor for liver and breast cancer in humans, but a lower incidence of breast carcinoma has been also reported in hypothyroid patients
In this work we have analyzed the influence of hypothyroidism on tumor progression and metastasis development using xenografts of parental and TRbeta1-expressing human hepatocarcinoma (SK-hep1) and breast cancer cells (MDA-MB-468). In agreement with our previous observations tumor invasiveness and metastasis formation was strongly repressed when TRbeta-expressing cells were injected into euthyroid nude mice. Whereas tumor growth was retarded when cells were inoculated into hypothyroid hosts, tumors had a more mesenchymal phenotype, were more invasive and metastatic growth was enhanced. Increased aggressiveness and tumor growth retardation was also observed with parental cells that do not express TRs.
These results show that changes in the stromal cells secondary to host hypothyroidism can modulate tumor progression and metastatic growth independently of the presence of TRs on the tumor cells. On the other hand, the finding that hypothyroidism can affect differentially tumor growth and invasiveness can contribute to the explanation of the confounding reports on the influence of thyroidal status in human cancer.
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