The densely populated Greater Cairo (GC) region suffers from severe air quality issues caused by high levels of anthropogenic activities, such as motorized traffic, industries, and agricultural biomass burning events, along with natural sources of particulate matter, such as wind erosion of arid surfaces. Surface-measured concentrations of particulate matter (PM₁₀), sulfur dioxide (SO₂), and ozone (O₃) and its precursor’s gases (nitrogen dioxide, NO₂; carbon monoxide, CO) were obtained for the GC region. The PM₁₀ concentrations were found to exceed remarkably the Egyptian guidelines (150 μg/m³). These high levels of PM₁₀ were recorded throughout 68% of the period of measurement in some industrial areas (El-Kolaly). The measured data of pollutants were used for both the evaluation of environmental pollution levels and the validation of the online-integrated regional climate chemistry model “RegCM-CHEM4.” Calculation of the bias between the model results and the measured data was used to evaluate the model performance in order to assess its ability in reproducing the chemical species over the area. The model was found to reproduce the seasonal cycle of the pollutants successfully, but with a large underestimation of the PM₁₀ values. Validation of the RegCM-CHEM4 indicated that the emission inventories of mobile sources and anthropogenic activities need to be improved especially with respect to local and regional activities in order to enhance air quality simulations over the GC region.

In this work, it was analyzed the behavior of three commercial activated carbons with different textural and chemical properties to adsorb individually metronidazole and lead ions from aqueous solution. Afterwards, the activated carbons were modified with citric acid to remove both compounds simultaneously. Both sets of activated carbons were characterized chemically and texturally. XPS analysis was performed to corroborate the adsorption mechanism of lead on the surface of the carbons. Finally, the intraparticle diffusion of both adsorbates was elucidated by the application of diffusional model in three dimensions. The results evidenced that adsorption mechanism for MNZ and Pb(II) is independent, the adsorption for MNZ is governed by π–π dispersive interactions, whereas Pb(II) adsorption is mainly controlled by electrostatic interactions. The binary adsorption equilibrium shows that the adsorption of MNZ is independent from the concentration of Pb(II), whereas the adsorption of Pb(II) is affected by the presence of MNZ at low concentrations (0.1 mmol L⁻¹), but it remains almost constant at concentrations of MNZ between 0.1 and 1.5 mmol L⁻¹. Finally, the mass transport of MNZ was faster than Pb(II) from the solution to the external surface of activated carbon and the mass flux of MNZ inside the particle was superior to the mass flux of Pb(II). Lastly, there might be an obstruction phenomenon with MNZ impeding Pb(II) to reach the active sites placed into the carbon’s microporosity structure. Graphical abstract

This paper represents a new proposed trade model of “Intercountries Trade Force (ITF)” which is inspired by Intermolecular Interaction Forces in chemical sciences, and has potential to compensate for the deficiencies of the gravity trade model proposed by Jan Tinbergen in 1962. The main differences between our new model and the earlier gravity trade theory are (i) there is a time-variant variable called the gravity index (GI) which means that the earlier gravity theory was treated as only a variable in our new proposed model and (ii) our new proposed trade model has a higher chance of adoption in the real trade world rather than the earlier gravity trade model which always needs to be expanded by scholars. In order to empirically test our new proposed trade model, we applied it in an empirical econometric model to analyze the Russian gas export to the EU member states, not explored earlier. Results revealed that our new trade proposed model adjusts with the empirical energy trade pattern.

Scientific interest is focusing on different approaches for characterising organic carbon (OC), elemental carbon (EC) and equivalent black carbon (eBC), although EUSAAR2 protocol has been established and frequently used in EU for regulatory purposes. Discrepancies are observed due to thermal protocols used for OC/EC determinations and the effect of the chemical-physical properties of aerosol using optical measurements for eBC. In this work, a long-term inter-comparison of carbon measurements with two widely used protocols (EUSAAR2 and NIOSH870) was performed on PM₂.₅ and PM₁₀ samples. The influence of the protocol on the evaluation of secondary organic aerosol (SOC) and on the correlation between EC and eBC was investigated. An extensive check of repeatability gave typical uncertainties of ~ 5% for TC and OC, and ~ 10% for EC for both thermal protocols. Results show that OC is statistically comparable between the two protocols but EC is significantly higher with EUSAAR2, especially during the warm season. The ratio OC/EC is lower with EUSAAR2, also showing a seasonality (lower values in the warm season) not observed with NIOSH870. Despite the differences in OC/EC ratios, the contribution of SOC to OC (~ 50%), evaluated using the EC-tracer method, did not differ significantly between the two protocols and for both size fractions. Further, SOC/OC ratios were comparable in cold and warm periods. eBC/EC ratios larger than one for both protocols were obtained, 1.62 (EUSAAR2) and 1.92 (NIOSH870), and also correlated with the ratio OC/EC for both protocols, especially in the cold season.

This paper explores the impact of shale gas and oil fracking wells on infants’ health at birth across Oklahoma counties. The empirical analysis makes use of the Dumitrescu-Hurlin causality test, as well as the (long-run) Pooled Mean Group method. The results clearly document that there is a unidirectional relationship between fracking activities and three alternative indexes of infants’ health at birth, as well as a significant impact of fracking on infants’ health indicators. In addition, the results illustrate the substantial role of fracking through the drinking water quality channel.

Indiscriminate disposal and open burning of sawmill and municipal solid wastes constitute hazards to the quality of the immediate environment and human health. This study assessed the levels of pollutants emitted by burning sawmill and municipal wastes, and their potential hazards. Nine selected sawmills and 6 municipal solid-waste dumps in Abeokuta metropolis were investigated. During waste burning, the concentrations of NO₂, SO₂, CO, H₂S, NH₃ and VOC were monitored in replicates at the dumpsites, 10 m, 20 m and the nearest houses using portable samplers (Aeroqual and Multi-RAE). Mean, ANOVA, correlation and regression statistical tools were used to analyse air quality data; air quality index (AQI) was employed to classify the hazard rating of the gaseous pollutants. Nearest neighbour analysis in ArcGIS 10.0 was used to investigate dumpsites location pattern within the city. The concentrations (mg/m³) of sampled parameters from source to nearest house (NH) at the dumpsites ranged as follows: < 0.002–0.175 (NO₂), < 0.002–0.235 (SO₂), 0.065–0.425 (H₂S), 13.98–47.40 (CO), 6.74–170.41 (NH₃) and 31.13–820.03 (VOC) in wet and dry seasons. The mean concentrations of NO₂, SO₂ and VOC were below permissible limits at most locations while CO values were higher at all dumpsite. Significant variations (p < 0.05) were observed in the concentrations of the monitored parameters except NO₂ values (SMW) in dry season. AQI rated NO₂ and SO₂ concentrations as “good” at all sites while CO emission ranged from unhealthy to hazardous across the dumpsites. In conclusion, the present locations of SMW and MSW dumps in the city degrade environmental quality and are unsafe for human health.

Urban forests are exposed to metals, such as manganese, copper, and zinc in the atmosphere that originate from anthropogenic activities, that include vehicle-related traffic, industries, construction sites, fossil fuel burning for heating and cooking purposes, and resuspension processes related to urban surfaces. Not only is the rich biodiversity of plant and animal species in forests under threat, but so are the biodiversity of soil, sustaining ecosystem functions, as well as human health. The objective of this study was therefore to determine the concentrations of manganese, copper, and zinc arising from urban, industrial, and traffic-related pollution in the remote and/or untouched urban indigenous forests using soil, leaf litter, and key forest organisms (mosses, lichens, and millipedes) in three forests (Platbos, Orange Kloof, and Newlands) in the Western Cape, South Africa. Elevated concentrations of these metals were found in the forests closest to the city, as well as at sites in close proximity of vehicle traffic.

This study evaluated the reutilization of waste materials (scrap tires, sewage sludge, and wood chips) to remove volatile organic compounds (VOCs) benzene/toluene/ethylbenzene/xylenes/trichloroethylene/cis-1,2-dichloroethylene (BTEX/TCE/cis-DCE), plasticizer di(2-ethylhexyl) phthalate (DEHP), and pharmaceutically active compound carbamazepine from artificially contaminated water. Different hybrid removal processes were developed: (1) 300 mg/L BTEX + 20 mg/L TCE + 10 mg/L cis-DCE + tires + Pseudomonas sp.; (2) 250 mg/L toluene + sewage sludge biochar + Pseudomonas sp.; (3) 100 mg/L DEHP + tires + Acinetobacter sp.; and (4) 20 mg/L carbamazepine + wood chips + Phanerochaete chrysosporium. For the hybrid process (1), the removal of xylenes, TCE, and cis-DCE was enhanced, resulted from the contribution of both physical adsorption and biological immobilization removal. The hybrid process (2) was also superior for the removal of DEHP and required a shorter time (2 days) for the bioremoval. For the process (3), the biochar promoted the microbial immobilization on its surface and substantially enhanced/speed up the bioremoval of toluene. The fungal immobilization on wood chips in the hybrid process (4) also improved the carbamazepine removal considerably (removal efficiencies of 61.3 ± 0.6%) compared to the suspended system without wood chips (removal efficiencies of 34.4 ± 1.8%). These hybrid processes would not only be promising for the bioremediation of environmentally concerned contaminants but also reutilize waste materials as sorbents without any further treatment.

This study aims to examine the convergence hypothesis of per capita carbon dioxide emission and its component such as coal, oil, and gas in the case of 53 countries covering the period of 1980 to 2016. In particular, we study whether countries are moving toward a common steady-state equilibrium condition in the per capita carbon emission or converging into different groups. To do so, this study used Phillips and Sul (Econometrica 75(6): 1771–1855, 2007, J Appl Econ 24(7): 1153–1185, 2009) technique. Our results show no evidence of convergence for full sample. However, our results support the evidence of two club convergence of total emission, emission from gas and petroleum consumption, while three clubs are noticed in case of per capita carbon dioxide emission from coal use. This invalidates the equality rule of participation of each country in climate change policy. Further, similar results emerge in case of total emission and petroleum where club 1 consists of mostly developed countries while club 2 has a large number of developing countries. Interestingly, we do not find any divergence behavior across all countries in the sample. We find that natural gas is the major component to drive the total carbon emission convergence in case of our sample countries.

Few studies have examined the effects of environmental concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) on the hematologic system of residents near a petrochemical complex. This study evaluated the potential effects of blood BTEX concentrations on the hematologic parameters of residents in a community near a petrochemical complex (contaminated group) and another community free of known petrochemical pollution (control group). Volunteer residents were randomly recruited. Each participant completed a questionnaire and donated blood samples to evaluate blood BTEX concentrations and hematologic parameters. We found the mean concentrations of blood BTEX of the contaminated group were 1.2 to 6.7 times higher than the control group. Multiple hematologic parameters of participants were significantly different between the two study groups. Inverse associations were found for ln-transformed blood benzene concentrations with mean corpuscular hemoglobin concentration (MCHC) (β = − 2.75) and platelet counts (β = −8.18). Several weaker associations were also observed between other compounds and multiple hematologic parameters. Our results suggest that the residents living near petrochemical complexes have higher blood BTEX concentrations. Furthermore, the increased blood BTEX levels in residents are associated with the reduction in RBC counts, hemoglobin concentration, hematocrit, MCHC, and platelet counts. This study provided particularly important information for the health risk assessment of residents living near petrochemical complexes.