Benzo[a]pyrene (B[a]P) is one of the polycyclic aromatic hydrocarbons which is formed due to smoking of foods, incomplete combustion of woods, vehicle exhausts, and cigarettes smokes. B[a]P gets entry into human and animal bodies mainly through their diets. Metabolic activation of B[a]P is required to induce mutagenesis and carcinogenesis in animal and human studies. Carotenoids and retinoids are phytochemicals that if ingested have multiple physiological interferences in the human and animal bodies. In this study, we firstly investigated the protective effects of β-carotene, β-apo-8-carotenal, retinol, and retinoic acid against B[a]P-induced mutagenicity and oxidative stress in human HepG2 cells. Secondly, we tested the hypothesis of modulating xenobiotic metabolizing enzymes (XMEs) by carotenoids and retinoids as a possible mechanism of protection by these micronutrients against B[a]P adverse effects. The obtained results declared that β-carotene and retinol significantly reduced B[a]P-induced mutagenicity and oxidative stress. Tested carotenoids and retinoids reduced B[a]P-induced phase I XMEs and induced B[a]P reduced phase II and III XMEs. Thus, the protective effects of these micronutrients are probably due to their ability of induction of phase II and III enzymes and interference with the induction of phase I enzymes by the promutagen, B[a]P. It is highly recommended to consume foods rich in these micronutrients in the areas of high PAH pollution.

Palm fruit husk, a lignocellulosic material, is an agricultural solid waste. Since raw palm fruit husk does not adsorb V (V), it was subjected to surface modification with a cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The surface-modified palm fruit husk showed adsorption capability for V (V). The maximum adsorption of V (V) takes place at pH 4. Adsorption equilibrium data were fitted to Langmuir, Freundlich, and Dubinin Radushkevich (D-R) isotherm models. Kinetic studies showed that the adsorption data fit second-order kinetic model better than first order. Desorption of V (V) proved that it is feasible to recover V (V) from the spent adsorbent. Effect of coexisting anions like Molybdate, sulfate, nitrate, phosphate, and thiocyanate on the adsorption of V (V) was also studied and the foreign ions compete for the adsorption sites with V (V) anionic species. Quantitative removal of V (V) was achieved from synthetic wastewater.

The study presents the spatial distribution of different forms of phosphorus in the sediments in Lake Chaohu, a large eutrophic Chinese lake, and their correlation with phosphorus content in pore water. The sediment and pore water samples were taken from 19 sampling sites. A sequential extraction was used to determine the contents of different forms of phosphorus in the sediments. The compositions and spatial distribution of different forms of phosphorus in the sediments and their correlation with orthophosphate and total phosphorus content in the pore water were studied. The following results were obtained: (1) the mean content of total phosphorus was 474.7 ± 20.5 mg/kg, with 390.8 ± 82.4 mg/kg for the eastern lake (N = 5), 469.0 ± 53.9 mg/kg for the western lake (N = 5), and 524.5 ± 185.3 mg/kg for rivers (N = 9); (2) the order of the proportions of the different forms of phosphorus was occluded phosphorus (Oc-P, 52.4%) > debris phosphorus (De-P, 14.2%) > auto-calcium-bound phosphorus (ACa-P, 13.5%) > aluminum-bound phosphorus (Al-P, 9.8%) > organic phosphorus (Or-P, 6.8%) > exchangeable phosphorus (Ex-P, 2.1%) > iron-bound phosphorus (Fe-P, 1.3%); (3) Ex-P, Al-P, and Fe-P had significantly positive correlations with orthophosphate and total phosphorus content in pore water, which showed that these forms of phosphorus were released more easily and had an indirect impact on lake eutrophication.

Advanced oxidation processes using semiconducting photocatalysts for the degradation of organic pollutants are a promising approach for the remediation of pesticide-contaminated wastewater. High photodegradation efficiency and stability of the photocatalyst are of key importance for practical application of the semiconductor. In this study, mesoporous TiO₂/ZrO₂ nanopowders were synthesized via two techniques; evaporation-induced self-assembly (EISA) and sol-gel using triblock copolymers Pluronic P123 and F127. The photodegradation activities of the composites were determined by employing the herbicide chloridazon as a model compound. Due to well-developed mesoporosity, the TiO₂/ZrO₂ nanocomposite synthesized by EISA displays high surface area and small crystallite sizes leading to higher photocatalytic activity than pristine TiO₂ prepared under similar condition and commercial Degussa P25 nanopowder. The optimum amount of zirconium required for the highest activities was identified and found to be 0.14 and 0.05 mol% for the EISA and sol-gel-prepared samples, respectively. Systematic studies of the post-thermal treatment step for both samples show that Zr inhibits an anatase-to-rutile phase transition only up to 600 °C, at higher temperature phase separation occurs. Samples synthesized by EISA method showed enhanced degradation activity than sol-gel-synthesized samples.

Mesothelioma is a malignant tumor mainly correlated to occupational asbestos exposure. Rare reports describe its occurrence also in animals, mainly linked to asbestos in the environment. Asbestos exposure is demonstrated by the appearance of characteristic histological hallmarks: asbestos containing ferruginous bodies that are iron-based structures forming around fibers and also other dust particles. Here we present a clinical case of a suspect of mesothelioma in the peritoneum of a dog with parallel histological observation of ferruginous bodies. To possibly correlate the dog tumor to environmental exposure, we performed X-ray fluorescence (XRF) analyses at two different synchrotrons to resolve the ferruginous bodies’ composition. While the histological examination diagnoses a tubulo-papillary mesothelioma, the XRF analyses show that ferruginous bodies contain Si particles, resembling formations of exogenous origin; however, the morphology is unlikely that of asbestos fibers. We speculate that the peritoneal mesothelioma of this dog could be related to environmental exposure to non-asbestos material.

The present study empirically investigates the impact of hydropower energy consumption on economic growth and CO₂ emissions in China, spanning the period 1965–2016. Using the ARDL bounds testing approach to cointegration, this study confirms the existence of a long-run relationship among the variables. Moreover, hydropower energy consumption has a positive impact on economic growth, while CO₂ emissions have a long-run negative impact on economic growth. However, economic growth and CO₂ emissions have a positive impact on hydropower energy consumption. Further, the study failed to provide a support of the environmental Kuznets curve (EKC) hypothesis for China. The Granger causality test reveals that there is a unidirectional causality running from hydropower energy consumption to economic growth. Furthermore, there is a bidirectional causality among the hydropower energy consumption, economic growth, and CO₂ emissions in the long run. Given these findings, we argue that hydropower energy consumption is considered as the driving force to enhance the economic growth in China.

As an important cause of global warming, CO₂ concentrations and their changes have aroused worldwide concern. Establishing explicit understanding of the spatial and temporal distributions of CO₂ concentrations at regional scale is a crucial technical problem for climate change research. High accuracy surface modeling (HASM) is employed in this paper using the output of the CO₂ concentrations from weather research and forecasting-chemistry (WRF-CHEM) as the driving fields, and the greenhouse gases observing satellite (GOSAT) retrieval XCO₂ data as the accuracy control conditions to obtain high accuracy XCO₂ fields. WRF-CHEM is an atmospheric chemical transport model designed for regional studies of CO₂ concentrations. Verified by ground- and space-based observations, WRF-CHEM has a limited ability to simulate the conditions of CO₂ concentrations. After conducting HASM, we obtain a higher accuracy distribution of the CO₂ in North China than those calculated using the classical Kriging and inverse distance weighted (IDW) interpolation methods, which were often used in past studies. The cross-validation also shows that the averaging mean absolute error (MAE) of the results from HASM is 1.12 ppmv, and the averaging root mean square error (RMSE) is 1.41 ppmv, both of which are lower than those of the Kriging and IDW methods. This study also analyses the space-time distributions and variations of the XCO₂ from the HASM results. This analysis shows that in February and March, there was the high value zone in the southern region of study area relating to heating in the winter and the dense population. The XCO₂ concentration decreased by the end of the heating period and during the growing period of April and May, and only some relatively high value zones continued to exist.

Ascorbic acid (AA), one of the best-known reactive oxygen species (ROS) scavengers, exhibits numerous functions such as antioxidant, anti-cancer, and anti-inflammatory effects. Increasing evidence demonstrates that oxidative stress plays an important role in testicular toxicity. In the present study, we investigated the protective effect of AA against cadmium (Cd)-induced blood-testis barrier (BTB) disruption. Sprague-Dawley (SD) rats were divided into four groups: the Cd-treated group received a single dose (s.c.) of 2 mg/kg BW cadmium chloride; the AA antagonism group received an injection of AA at a dose of 400 mg/kg BW (200 mg 24 h prior to Cd treatment and 200 mg 24 h following Cd treatment); and the control groups received an equal volume of saline or an equal dose of AA. As expected, ROS expression was upregulated in the Cd-treated rats, accompanied by an increase in malondialdehyde (MDA). Interestingly, AA suppressed Cd-induced oxidative stress by decreasing the levels of ROS and MDA and increasing the activity of superoxide dismutase (SOD) and catalase (CAT). In addition, AA also reduced BTB disruption by inhibiting TGF-β3 activation and p38 MAPK phosphorylation. Significant decreases in occludin and claudin-11 expression were observed in the Cd-treated rats, whereas AA administration attenuated this effect. Moreover, testicular histopathology and transmission electron microscopy further demonstrated the protective effects of AA against Cd-induced BTB damage. In conclusion, the results of the present study suggest that AA protects BTB destruction via the inhibition of oxidative stress and the TGF-β3/p38 MAPK signalling pathway in the testis of Cd-exposed rats.

As economic integration in the world continues to advance, energy consumption and carbon emissions in various regions have also become increasingly interdependent. In order to better understand the regional interaction of carbon emissions, this paper employs a three-region input-output approach to explore the linkage of CO₂ emissions among China, EU, and USA. Based on the world input-output table and environment account of World Input-Output Database (WIOD) in 2009, we calculate the carbon emission multiplier effect, spillover effect, and feedback effect and carry out the analysis from the regional and sectoral levels. The results show that, first of all, the carbon emission multiplier effect of each region is larger than the spillover and feedback effects. Second, EU and USA have higher carbon emission spillover effect on China than China’s carbon emission spillover effect on them. Finally, the carbon multiplier effects in different sectors have different characteristics.

MCM-41 mesopore was prepared by hydrothermal method and used for synthesis of polyaniline/MCM-41 nanocomposite via in situ polymerization. The nanocomposite was blended with polysulfone to prepare mixed matrix membrane in different content of nanocomposite by phase inversion method. Structural and surface properties of the samples were characterized by SEM, XRD, FTIR, AFM, TGA, BET, and zeta potential measurements. Effect of the nanocomposite content on the hydrophilicity, porosity, and permeability of the membrane was determined. Membrane performance was evaluated for removal of lead ions in dynamic filtration and static adsorption. The membranes were found as effective adsorptive filters for removal of lead ions via interactions between active sites of nanocomposite in membrane structure and lead ions during filtration. Results of batch experiments proved adsorptive mechanism of membranes for removal of lead ions with the maximum adsorption capacity of 19.6 mg/g.