Organophosphate esters (OPEs), as a class of emerging flame retardant and plasticizers, have attracted particular attention due to their ubiquitous existence in the environment and potential effects on human health. Here, we investigated the levels of OPEs in human serum and examined the role of demographic variables on the body burden of such compounds. Of 11 OPEs screened, 8 were detected in human serum samples collected from a population (n = 89) in Bohai Bay, North China. The ∑OPE concentrations ranged from 4.7 to 948 ng/g lipid weight (lw), with a median concentration of 243 ng/g lw. Tris(2-chloroethyl)phosphate (TCEP) was identified as the most abundant OPEs with a median concentration of 214 ng/g lw. The concentrations of the triphenyl phosphate (TPhP) in older adults were higher than those in young adults (p < 0.05), and lower concentrations of tri-iso-butyl phosphate (TIBP) were observed in female samples compared to males. Furthermore, significant differences were observed in tri-n-propyl phosphate (TPrP) concentrations between urban and rural residence groups (p < 0.05). This study provides important information on the accumulation potential of OPEs in human bodies and suggests the need for further investigation to understand the potential human health risk.

Understanding the hydrodynamic behavior of side jets in compound open channels with vegetated floodplain is crucial to jet dilution, sediment transport, and bank stability. Large eddy simulation was used to study horizontal side jets in compound open channels with vegetated floodplain. Predicted mean velocity, turbulent kinetic energy, and secondary currents were compared with experimental data, with a good agreement between measured and calculated data. Analyses of bed shear stress showed that vegetation in the floodplain increases the total drag and decreases bed shear stress, thus governing sediment transport and protecting the bank. The transport mechanism was quantitatively investigated by the quadrant analysis, concentration, and Reynolds flux. The ejection and sweep events were major contributors to the momentum and scalar flux transport. Analyses of concentration and Reynolds flux showed that the secondary flow influenced the spreading of the jet and the location of the concentration peaks, and the distribution of concentration and Reynolds flux did not strictly follow Fickian law in the whole region due to the effect of secondary flow on the concentration distributions. Additionally, the typical vortexes and spatiotemporal evolution of vortex structures in compound open channels, especially those near the junction between the main channel and floodplain, were successfully demonstrated.

Zinc is one of the important essential trace minerals to human health due to its antioxidant properties. The present study was conducted to elucidate its potential protective role against maneb-induced nephrotoxicity. For this purpose, animals were randomly divided into four groups of six each. Mice of group I (negative controls) have received daily 0.5 ml of distilled water, a solvent of maneb. Mice of group II (MB) have received 30 mg/kg bw of maneb daily by intraperitoneal way. Mice of group III (MB + Zn) have received the same dose of maneb as group II, along with ZnSO₄ (30 mg/kg bw) daily. Mice of group IV (Zn), considered as positive controls, have received the same dose of ZnSO₄ as group III daily. Our results revealed that ZnSO₄ co-administration to maneb-treated mice decreased kidney levels of malondialdehyde, hydrogen peroxide, protein carbonyls, and advanced oxidation protein products; the levels of non-enzymatic antioxidants like vitamin C, glutathione, and metallothionein. It recovered the alteration of antioxidant enzyme activities (catalase, superoxide dismutase, and glutathione peroxidase) and attenuated DNA fragmentation. Furthermore, this essential trace element was also able to alleviate kidney biomarkers’ alterations by lowering plasma levels of creatinine, urea, uric acid, and lactate dehydrogenase. In addition, the histopathological changes induced by maneb were improved following zinc administration. Our results indicated that zinc might be beneficial against maneb-induced renal oxidative damage in mice.

Fipronil (FIP) is a highly effective, broad-use insecticide that belongs to the phenylpyrazole chemical group. It is extensively used in the agriculture and veterinary medicine for controlling a wide variety of pests. Though FIP showed lower toxicity in vertebrates than in insects, it was recognized to have a variety of toxic effects in mammals. The present study was undertaken to evaluate FIP-induced alterations in the blood biochemical markers and oxidative stress parameters in male albino mice via oral sub-acute toxicity exposure. The possible ameliorative effect of the pretreatment with selenium plus α-tocopherol (vitamin E) against the harmful effects of FIP was also investigated. Mice in FIP-test groups were exposed to different sublethal doses, i.e., 1.43, 2.87, and 4.78 mg active ingredient (AI)/kg body weight (b.w.), equal to 1/100, 1/50, and 1/30 LD₅₀ of FIP, respectively, for 28 days. Mice in the amelioration groups were orally administered with selenium + vitamin E (0.3 mg + 22.5 mg/kg b.w., respectively) 14 days prior to exposure to the higher dose (4.78 mg/kg) of FIP for another 14 days. Fipronil exposure at medium and high doses showed lowered values of red blood cell count (RBC), hematocrit (HCT), hemoglobin (HGB), white blood cell (WBC), and platelet (PLT) counts after 28-day exposure, compared to the control. All three doses caused significant increases in levels of liver-function biomarkers, i.e., aspartate amino transaminase (AST), alanine amino transaminase (ALT), alkaline phosphatase (ALP), cholesterol, and bilirubin levels compared to the control. Levels of biomarkers related to kidney functions, i.e., urea, uric acid, and creatinine, increased significantly than these of the control. Likewise, the oxidative stress indices, i.e., hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), significantly increased at the higher and medium doses, while antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD), decreased significantly. On the other hand, prior administration of selenium + vitamin E in the FIP-exposed mice led to restore values of most hematological parameters nearly to these of the control. Also, the levels of AST, total protein, and creatinine seemed to be restored to the control values. Interestingly, pretreatment with selenium + vitamin E restored the levels of antioxidant enzymes, CAT and SOD, to the control values, whereas, oxidative stress indices, H₂O₂ and MDA, remained significantly high. It is our thought that the sublethal dose less than 1.43 mg/kg b.w. of commercial formulation of FIP (COACH® 200 SC) could be considered as no-observed-adverse-effect-level(NOAEL) under our present experimental conditions at short-term toxicity study. On the other hand, the higher sublethal doses, 4.78 and 2.87 mg/kg b.w., induced significant adverse effects in biomarkers and may be deleterious to human health following long-term exposure.

This study investigates the effects of energy consumption, democracy and globalization on environmental degradation in the context of the environmental Kuznets curve (EKC) for South Africa between 1971 and 2014. To this end, the study applies the combined Bayer-Hanck cointegration test and the fully modified ordinary least squares (FM-OLS) estimation approach. The empirical results confirm the presence of cointegration among the variables, and thus validate the EKC hypothesis for South Africa. In addition, while energy consumption increases environmental degradation, the effect of democracy is positively insignificant. The finding also suggests that globalization condenses environmental degradation. The results of the long-run causal relationship divulge that economic growth, energy consumption, democracy and globalization Granger-cause environmental degradation. The results also find causality running from CO₂ emissions, economic growth, democracy and globalization to energy consumption. In the short run, a causality is found running from globalization to CO₂ emissions, energy consumption to CO₂ emissions and globalization to energy consumption. In addition, economic growth is said to Granger-cause democracy while democracy Granger-causes CO₂ emissions. These results are validated by the innovation accounting tests.

This study explores the interaction among coal consumption, pollutant emissions, and real income for South Africa in a multivariate setting. To achieve this objective, annual frequency data spanning from 1965 to 2017 is used for analysis. A series of econometrics tests were conducted ranging from stationarity and non-stationarity tests for unit root properties of the variables under consideration. Empirical evidence finds support for the inverted U-shaped pattern between energy consumption and environmental degradation in South Africa. The Toda-Yamamoto Granger causality test shows a feedback causality between economic growth and carbon dioxide emissions, as well as between GDP and coal consumption. All these highlighted findings have inherent environmental implications. Based on these outcomes, policy directions such as diversification of the South Africa energy mix to renewables and cleaner energy sources and also the adoption of carbon capturing and storage techniques were suggested to engender a cleaner and friendlier environment.

Heavy metals like Cd and Hg removal using novel graphene oxide/ferrous sulfate (GO/FeSO₄) was taken for experimental studies and analysis. In this work, GO/ FeSO₄ was synthesized by both modified Hummer’s and chemical precipitation method. The synthesized composite was characterized by field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy for their properties. Brunauer Emmett-Teller (BET) analysis was characterized for the surface analysis of the prepared nanocomposites. FESEM images exhibit flake-like structures in surface morphological studies. FTIR peaks confirmed the presence of carboxyl groups in GO. Raman spectroscopy intensity peak [ID/IG ratio1.18] confirmed the synthesized sample was GO. The experimental parameters such as initial concentration, pH, and adsorbent dosage were optimized to achieve maximum heavy metal removal efficiency. The influence of initial heavy metal concentration (0.2–1 mg/L), pH of solution (pH 3–7), and adsorbent dosage (1–5 g/L) was studied and reported. Adsorption kinetic studies were performed and the process was found to fit well with pseudo-second-order kinetics.

Soil-exchangeable aluminum (Al) has toxic effects on living organisms in acidic soils. Earthworm presence and activity can alter soil pH, which has a significant influence on Al toxicity. However, the effects of earthworms on soil Al toxicity and fractions are still largely unknown. This laboratory study focused on the effects of three earthworm species (endogeics Pontoscolex corethrurus and Amynthas robustus, anecis Amynthas aspergillum) on soil acidification, Al fraction distribution, and base cation release. Three native earthworm species and a soil (latosolic red soil) collected from a botanical garden in South China were incubated under laboratory conditions. After 40 days of incubation, six Al fractions in soil, namely exchangeable (AlEₓ), weakly organically bound (AlOᵣw), organically bound (AlOᵣ), amorphous (AlAₘₒ), Al occluded in crystalline iron oxides (AlOₓᵢ), and amorphous aluminosilicate and gibbsite (AlAₐg) fractions, were extracted using a sequential procedure. Soil pH; organic carbon; total nitrogen; total Al (AlTₒₜₐₗ); exchangeable K, Na, Ca, Mg contents; and CEC were determined as well. Compared to control soil, pH values increased by 0.79, 0.41, and 0.57 units in casts in the presence of P. corethrurus, A. robustus, and A. aspergillum, and 0.70, 0.32, and 0.50 units in non-ingested soil, respectively. Compared to control soil, the 61.7%, 30.7%, and 36.1% of AlEₓ contents in casts and 68.5%, 25.9%, and 39.0% of AlEₓ in non-ingested soil significantly decreased with the addition of P. corethrurus, A. robustus, and A. aspergillum, respectively. Moreover, compared to control soil, the 78.7%, 37.7%, and 40.1% of exchangeable Ca²⁺ and 12.3%, 24.7%, and 26.8% of exchangeable Mg²⁺ contents in casts significantly increased with the presence of P. corethrurus, A. robustus, and A. aspergillum, respectively. Soil treated with P. corethrurus had higher soil pH values, exchangeable Ca²⁺ contents, and lower AlEₓ than those with A. robustus and A. aspergillum. Results of principal component analyses showed that P. corethrurus, A. robustus, and A. aspergillum casts and non-ingested soil differ for soil pH, Al fractions, and exchangeable base cations release. These results indicate that earthworms, especially P. corethrurus, can reduce soil Al toxicity, increase soil pH, and affect the release of exchangeable base cations.

Applying a global DEA model based on non-radial directional distance function, this paper constructs a comprehensive efficiency index to estimate green development level and further identifies the influencing mechanism of technology R&D on green development in China’s industrial sector. The results demonstrate that the level of green development in China’s industrial sector declined year by year and the average was 0.27, and it also shows significant regional characteristics within the sample period. Besides, the environment pollution transferred from the east to the central and the west. In addition, the results also indicate that there is a threshold effect for the impact of technology R&D on China’s industrial green development. Based on the volume of the trade openness, this effect presents a “N”-type characteristic that tilts to the right. According to the research results, the corresponding policy recommendations are put forward, which may be of great importance to improve the green development level in China’s industrial sector.

Cave dwelling is an ancient and unique type of residence in the Loess Plateau of Northern China, where the economics are less-developed. The majority of the local dwellers rely on traditional solid fuels for cooking and heating, which can emit large amounts of particles into both indoor and outdoor environments. In this study, we measured the real-time household concentrations of PM₂.₅ and explored the association between personal daily PM₂.₅ exposure and blood pressure (BP). Cooking and heating activities with different energies made a great variation in the household PM₂.₅ air pollution, and residents using biomass had the highest personal PM₂.₅ exposure. Temperature and relative humidity are both significantly linear correlated with household PM₂.₅ air pollution. Besides, systolic blood pressure (SBP) was demonstrated to be positively associated with personal PM₂.₅ exposure: with each 10-μg/m³ incremental PM₂.₅ concentration when controlling all the other factors, SBP will increase by 0.36 mmHg (95% confident interval (CI) 0.05–0.0.77 mmHg). If solid fuels could be replaced with clean energies, personal PM₂.₅ exposure and SBP would reduce by more than 21% and 3.7%, respectively, calling for efficient intervention programs to mitigate household air pollution of cave dwellings and protect health of those residents.