Paddy rice, one of the most important food crops in Southeast Asia, is considered a main source of human exposure to heavy metal contamination because it efficiently accumulates heavy metals. In the present study, of Japonica rice grains, straw, roots, leaves, and husks and rhizosphere paddy soils (0–20 cm and 20–40 cm depth) were collected from Zunyi in northern Guizhou Province, China. The forms of heavy metals, including Cr, Cd, Pb, Cu, and Zn, in the two soil profiles were investigated using Tessier’s five-stage sequential extraction procedure. There was no heavy metal pollution in the study area based on the evaluation of the geo-accumulation index and the potential ecological risk index. Accumulation varied from one area to another, and the highest metal accumulation was found in the order of root > stems > leaves. The bioaccumulation factor (BCF) results revealed that during the grain-filling stage, the rice had high BCF values (> 1) for Cd and Zn. The target hazard quotient (THQ) of ingestion peaked for Cd and reached its minimum level for Zn in not only in adults but also in children. The THQ was ranked as Cd > Cu > Pb > Cr > Zn for both adults and children. The hazard index values for adults and children for the five heavy metals were 1.81 × 10⁻³ and 1.55 × 10⁻³, respectively, indicating that these metals have little effect on the human body. The lifetime carcinogenic risk values for local adults and children were 4.28 × 10⁻⁵ and 5.92 × 10⁻⁵, respectively, both of which were within the tolerable to acceptable risk range. In summary, obvious hazards for local adults and children were not observed in this study. Considering the total amount and chemical forms of Cd, it is necessary to notify the appropriate departments about the possible rice contamination caused by Cd in the soil.

Using king grass (Pennisetum purpureum Schumach. × Pennisetum glaucum (L.) R.Br.) for phytoextraction is a promising technology for producing large amounts of biomass fuel while remediating contaminated soil. To assess the practical phytoextraction capacity of king grass, we conducted a field experiment with three different soil types (loam, sandy loam, clay loam) and cadmium (Cd) concentrations (0, 0.25, 0.5, 1, 2, 4, 8, and 16 mg kg⁻¹, aged stably for 6 years). King grass were harvested at two different periods (elongation and maturity) to identify the optimal harvest time for extraction efficiency. The results showed that all treatments had bioconcentration factor (BCF) > 1 and translocation factor (TF) < 1; Cd is mainly stored in the roots. However, due to a high shoot biomass, the highest quantity of Cd extracted from shoots was 2.75 mg plant⁻¹, from the experimental group with 16 mg kg⁻¹ Cd added in sandy loam. A significant positive relationship (P < 0.05) was observed between the amount of Cd extracted from king grass stems, leaves, and roots from soil with the diethylene triamine pentacetate acid (DTPA) extractable Cd concentration. The Cd concentration in shoots at the maturity stage is lower than at the elongation stage, mainly due to the effect of biological dilution. Meanwhile, there is significantly more biomass (P < 0.05) at the maturity stage than at the elongation stage. At the latter, the extraction efficiency of the three soils was loam > sandy loam > clay loam, while at maturity it was sandy loam > clay loam > loam. This change in extraction efficiency can be attributed mainly to differences in soil DTPA-extractable Cd concentration and growth rate caused by differences in soil physical and chemical properties. According to calculations from multiple harvests using three types of soil, remediating contaminated soil with 0–16 mg kg⁻¹ Cd would take 13.9–224.5 and 19.5–250.6 years, extracting 7.21–265.23 and 4.96–330.52 g ha⁻¹ Cd while producing 33.62–66.50 and 73.8–110.5 t ha⁻¹ dry biomass at the elongation (90 days) and maturity (120 days) stages, respectively. In summary, king grass has major potential for remediating Cd-contaminated soil while producing large volumes of biofuel.

This paper explores the dynamic relationship between CO₂ emissions, urbanization, trade openness, and technology innovation based on the panel data of 13 Asian countries over the period of 1985–2019. The STIRPAT model is used as a framework for the analysis. For estimation purpose, panel cointegration and FMOLS techniques are utilized. The causality between the concerned variables is also examined by estimating a panel VECM model. The results of panel cointegration reveal the presence of long-run relationship among the variables. FMOLS estimations show that energy consumption increases CO₂ emissions while technology change, urbanization, and trade openness compact it. Panel causality analysis indicates bidirectional causality between urbanization and emissions, technology and emissions, trade and emissions, and trade and technology in the long run. Overall findings support the idea that urbanization, technology innovation, and trade openness can play important role to achieve environmental sustainability.

A critical problem derived from airport operations is the environmental impact of runoff water. Airport runoff includes a complex mixture of pollutants, e.g., from deicing agents, that may affect negatively natural water bodies. This study assesses the spatial and temporal aquatic ecotoxicity of runoff water and possible aeroplane drift in a German airport. Over winter 2012–2013, from November to May, water samples were collected within the airport and surrounding area. These samples were analyzed using traditional physicochemical analysis and biotests with two aquatic organisms from different trophic levels, Lemna gibba and Aliivibrio fischeri. Overall, the samples examined in this study were relatively non-toxic to the tested organisms. The physicochemical parameters were mainly influenced by the sampling period being higher in colder months. In contrast, the ecotoxicity was influenced by the sampling site. For sites within the airport, a high correlation between the physicochemical parameters (EC and TOC) and toxicity in L. gibba was found. These correlations were not evident in samples taken outside the airport or when A. fischeri was used as a bioindicator. However, a pronounced seasonality has been observed, linked to the coldest months with average inhibition values of 50% in L. gibba and 25% in A. fischeri, particularly in January. Both biotests yielded differing results; therefore, more biotests should be included. However, L. gibba showed a good response with this type of water samples to be included in future studies together with detailed chemical analysis. The present study provides data to assess the potential ecotoxicological effects of airport runoff affected by winter operations.

The Cipeles watershed is the largest subsystem of the Cimanuk watershed, which is located in an agricultural area. Some segments of the Cipeles River are appropriate for aquatic life habitat. To assess the pollutant risk from heavy metals, which tend to accumulate in the environment, this study determined the heavy metal concentrations as a basic database, calculate the heavy metal pollution index (HMPI), and assess the correlation between heavy metals from the surface and pore waters of Cipeles River. Samples from 11 sampling stations at the end of the wet season were collected, preserved, and characterized using inductively coupled plasma mass spectrometry. The heavy metal concentrations were then plotted on a map using a geographic information system. As a result, the heavy metal occurrence in pore water was found to be Mn > Fe > Ba > Co > Zn > Cu > Pb > Cr in the order of abundance, while the order was slightly different in surface water, i.e., Fe > Mn > Zn > Ba > Cu > Pb > Co > Cr. Both pore and surface waters showed similar dominance for iron and manganese, where they mostly originated from the run-off water from the laterite and alluvial soils at the sampling locations. The other micro-concentrations of heavy metals indicate the anthropogenic source of pollutants. The HMPI indicated a low level in the upstream area, medium to high levels in the city center, and high levels in the downstream area. Moreover, there is a significant correlation between the heavy metal concentration at pore and surface waters, especially for Mn and Co in the city area and also Zn and Ba in the downstream area.

Obesity and physical inactivity threaten human health, and both could be solved with exercise. However, a higher amount of pollutants is inhaled during exercise. Exposure to air pollution increases the incidence and progression of diseases. Therefore, the aim of the study was to investigate the rate of pollution inhalation of lean, overweight, and obese individuals in a low and high-intensity hypothetical exercise session. Healthy sedentary men (n = 135) classified as lean, overweight, or obese were enrolled in our study. All participants performed a cardiopulmonary exercise testing (CPX) to collect ventilation rate (VE) data, which was used to predict total ventilation and pollutant inhalation of a 5-km running session. Air pollutant concentration of São Paulo City, Brazil was evaluated and the toxicological risk was estimated based on the potential intake dose. The concentrations of PM₂.₅ were 29.57 μg/m³ and 51.71 μg/m³, PM₁₀ were 45.85 μg/m³ and 74 μg/m³, NO₂ were 63.71 μg/m³ and 66.65 μg/m³, and O₃ were 69 μg/m³ and 37 μg/m³, respectively in the summer and winter. In the hypothetical exercise session, total VE and time in both the first and second threshold were increased in the obese group (p < 0.001) (p < 0.001). The inhalation of PM₂.₅, PM₁₀, NO₂, and O₃, during the hypothetical session, was increased in obese individuals (p < 0.001). Obese individuals should be considered a susceptible population, once they are more exposed to air pollution during exercise.

The present study focused on the full valorization of the tomato by-product, also known as tomato pomace consisting mainly of tomato peels and tomato seeds, by recovering natural antioxidants and edible oil, and subsequently reutilizing the leftover solid residues for the production of low-cost biosorbent. The tomato peel extract recovered using ethanol as food-grade solvent contained high phenol and flavonoid contents (199.35 ± 0.35-mg gallic acid equivalents (GAE)/g and 102.10 ± 0.03-mg quercetin equivalent (QE)/g, respectively). Even its lower content of lycopene (3.67 ± 0.04 mg/100 g), tomato peel extract showed potent antioxidant activity and can be therefore used as natural antioxidants either for food or cosmetic applications. High nutritional quality edible oil (17.15%) was extracted from tomato seeds and showed richness in unsaturated fatty acids (74.62%), with linoleic acid being the most abundant polyunsaturated fatty acid (49.70%). After recovery of these valuable compounds, the extraction solid leftovers were used to produce low-cost biosorbent tested for dye removal. Results showed that the highest biosorption yields were increasingly attributed to the acidic, direct, anthraquinone, then reactive dyes. Overall, the obtained results strongly support the complete utilization of tomato pomace for the recovery of valuable compounds and the sequential production of low-cost biosorbent.

In this study, the effects of As-contaminated groundwater by various minerals in the soil were evaluated. The influence of As on microbial inhibition and activities influenced by soil minerals such as clay minerals (bentonite and kaolinite) and iron oxides (hematite, goethite, and magnetite) were investigated. The method used to evaluate the effects of soil minerals on As-contaminated groundwater was to indirectly measure microbial activity by two methods, measurement of optical density (OD) and fluorescein diacetate (FDA) hydrolysis. This study used Pseudomonas jinjuensis, a microorganism commonly found in soil and groundwater. The measurement of OD is a simple and quick method of identifying the growth of microorganisms, affecting turbidity up to dead cells after dead phase, making it difficult to identify actual living microorganisms; thus, it was inappropriate for toxicity assessment. However, the use of FDA is able to measure the bioavailability of microorganisms due to actual As contamination by the luminescence of the fluorescein caused by the enzymes of living microbes. The bentonite and hematite showed that promoting bacteria activity of 140.5% and 7.9%, respectively, and reducing the negative impact from As to bacteria, constantly, magnetite had a negative impact on bacteria activity. These results indicate that the clay minerals and iron oxides influenced the bioavailability of As in groundwater. Also, surface area and cation exchange capacity (CEC) of clay minerals and iron oxides were important parameters on the bioavailability of As.

In order to further explore the adsorption mechanism of chromium ion by biochar, organic components (OCs) and inorganic components (ICs) of biochar (RC) were prepared, and adsorption experiments of chromium ions by these types of carbon (RC, OC, IC) were performed. The three types of carbon were characterized before and after adsorption of chromium ions, using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Boehm titration, and zero charge (pHₚzc). Results showed that the adsorption efficiency of IC on trivalent chromium (Cr³⁺) was the strongest, ion exchange of Cr³⁺ with metal cations present on IC being the main adsorption mechanism, accounting for 61% of the total adsorption capacity. Among the metal ions, K⁺ accounted for about 51%. The REDOX between Cr³⁺ and carboxyl accounted for 20% of the total adsorption capacity. Other adsorption mechanisms, such as chelation between Cr³⁺ and carboxyl, and co-precipitation between Cr³⁺ and carbonate, occupied a small proportion. OC showed the largest adsorption capacity to hexavalent chromium (Cr⁶⁺). The adsorption mechanism of OC to Cr⁶⁺ was the result of combined actions, such as electrostatic attraction, and REDOX between Cr⁶⁺ with the aromatic π-conjugated system and reductive functional groups like hydroxyl. Among them, the REDOX accounted for 53% of the total adsorption of Cr⁶⁺ by OC.

This study examines the effect of financial development (FD) and foreign direct investment (FDI) on the environmental quality for the panel of 90 belt and road countries from 1990 to 2017. This study advances the knowledge of financial development by using the new comprehensive index, which is based on access, depth, and efficiency of financial markets and financial institutions and incorporated foreign direct investment as an important determinant of environmental quality. By applying the Driscoll-Kraay standard error pooled ordinary least square method, the empirical findings reveal that FD deteriorates the environmental quality by increasing the CO₂ emissions, while FDI improves environmental quality and the relationship between economic growth (EG) and CO₂ emissions is inverted U-shaped, i.e., presence of EKC hypothesis. The energy consumption and urbanization pollute the environment, while trade openness enhances the quality of the environment. Furthermore, the Dumitrescu-Hurlin (DH) panel causality test result confirms that the bidirectional causality exists among FD, trade openness, energy consumption, and urbanization with CO₂ emissions. The empirical results provide new insights for policymakers and also have several implications for the betterment of environmental quality.