It is well known that road transport emits various trace elements into the environment, which are deposited in soils in the vicinity of roads, so-called roadside soils, and thus contributes to the deterioration of their chemical state. The aim of this work was to determine concentrations of some metals and metalloids (arsenic (As), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), vanadium (V), and zinc (Zn)) in soils from crossroads with traffic signals, which are characterized by deceleration of vehicles and increased emissions of elements related mainly to brake and tyre wear. The results confirmed a moderate enrichment of soils with Cu, Pb, and Zn (enrichment factor (EF) values > 2) and significant enrichment for Sb (EF > 5), while the other elements showed no or minimal enrichment. The age of crossroads proved to have a positive influence on the accumulation of some elements in soils with the largest differences for Cu, Fe, Pb, Sb, and Zn (p < 0.001). Traffic volumes expressed as the average daily traffic intensity (ADTI) also positively influenced soil concentrations of Cr, Cu, Pb, Sb, and Zn, while distance to the crossroad had a significant negative effect on the soil concentration of Cu, Sb, and Zn (p < 0.001). The stable isotopic ratios of Pb, ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb, ranging from 1.1414 to 1.2046 and from 2.0375 to 2.1246, respectively, pointed to the mixed natural-anthropic origin of Pb in the soils of crossroads with a visible contribution of traffic-related sources. Based on the above findings combined with covariance among the studied elements using statistical methods applied to compositionally transformed data, it was possible to show that Cu, Pb, Sb, and Zn clearly originated from road traffic.

To examine pesticide mixture toxicity to aqueous organisms, we assessed the single and combined toxicities of thiamethoxam and other four pesticides (chlorpyrifos, beta-cypermethrin, tetraconazole, and azoxystrobin) to the rare minnow (Gobiocypris rarus). Data from 96-h semi-static toxicity assays of various developmental phases (embryonic, larval, juvenile, and adult phases) showed that beta-cypermethrin, chlorpyrifos, and azoxystrobin had the highest toxicities to G. rarus, and their LC₅₀ values ranged from 0.0031 to 0.86 mg a.i. L⁻¹, from 0.016 to 6.38 mg a.i. L⁻¹, and from 0.39 to 1.08 mg a.i. L⁻¹, respectively. Tetraconazole displayed a comparatively high toxicity, and its LC₅₀ values ranged from 3.48 to 16.73 mg a.i. L⁻¹. By contrast, thiamethoxam exhibited the lowest toxic effect with LC₅₀ values ranging from 37.85 to 351.9 mg a.i. L⁻¹. Rare minnow larvae were more sensitive than embryos to all the pesticides tested. Our data showed that a pesticide mixture of thiamethoxam–tetraconazole elicited synergetic toxicity to G. rarus. Moreover, pesticide mixtures containing beta-cypermethrin in combination with chlorpyrifos or tetraconazole also had synergetic toxicities to fish. The majority of pesticides are presumed to have additive toxicity, while our data emphasized that the concurrent existence of some chemicals in the aqueous circumstance could cause synergetic toxic effect, leading to severe loss to the aqueous environments in comparison with their single toxicities. Thence, the synergetic impacts of chemical mixtures should be considered when assessing the ecological risk of chemicals.

Anaerobic reactors have been spreading in places with tropical climate and in developing countries. Their association with aerobic reactors provides great removal of carbonaceous matter with lower energy consumption and sludge production, although it does not allow the reduction in the concentration of total nitrogen. An alternative that could provide nitrogen removal without the construction of new reactors would be the nitrified effluent recirculation to the anaerobic reactor, in which denitrification would take place. Therefore, in this study, we sought to perform the nitrified effluent recirculation to the packed bed reactor (PBR) and UASB and concluded the following: (a) due to the presence of filling material, PBR tended to present a better performance in denitrification and removal of organic matter and suspended solids than the UASB reactor; (b) when performing the nitrified effluent recirculation to anaerobic reactors, the COD/NO₃⁻-N ratio must not be less than 6; (c) the concentration of N₂O in the biogas of both reactors remained below the detection limit, minimizing the production of greenhouse gases; and (d) the limitation of organic matter promoted partial denitrification, creating conditions for the emergence of anammox bacteria in the sludge.

The remediation of Pb, Cd, and Zn contaminated soil by ex situ EDTA washing was investigated in two pot experiments. We tested the influence of (i) 0, 0.5, 1.0, and 1.5%wt zero-valent iron (ZVI) and (ii) a combination of 5%wt vermicompost, 2%wt biochar, and 1%wt ZVI on the metal availability in EDTA-washed soil using different soil extracts (Aqua regia, NH₄NO₃) and plant concentrations. We found that EDTA soil washing significantly reduced the total concentration of Pb, Cd, and Zn and significantly reduced the Cd and Zn plant uptake. Residual EDTA was detected in water extracts causing the formation of highly available Pb-EDTA complexes. While organic amendments had no significant effect on Pb behavior in washed soils, an amendment of ≥ 1%wt ZVI successfully reduced EDTA concentrations, Pb bioavailability, and plant uptake. Our results suggest that Pb-EDTA complexes adsorb to a Fe oxyhydroxide layer, quickly developing on the ZVI surface. The increase in ZVI application strongly decreases Zn concentrations in plant tissue, whereas the uptake of Cd was not reduced, but even slightly increased. Soil washing did not affect plant productivity and organic amendments improved biomass production.

Evaluating the bioaccumulation and health risk of heavy metals in soil-crop systems is essential in Liujiang karst regions. In the current study, the single and comprehensive uptake effects of heavy metals (i.e., Cu, Cr, Cd, As, and Zn) between rice and sugarcane and their rhizosphere soils were investigated. The estimated daily ingestion (EDI), target hazard quotient (THQ), and hazard index (HI) were estimated for health risk assessments. The results showed that the mean contents of Cu, Cr, Cd, As, and Zn in rice soils were 25.8, 168, 1.91, 20.0, and 160 mg/kg, respectively, and those in sugarcane soils were 28.8, 186, 0.44, 31.0, and 108 mg/kg. Rice soils were mainly contaminated by Cd, and Cd and Cr were the main pollutants in sugarcane soils. The average concentrations of Cu, Cr, Cd, As, and Zn in rice grains were 1.79, 0.15, 0.16, 0.11, and 12.7 mg/kg, respectively, and in sugarcanes were 0.10, 0.036, 0.022, 0.006, and 0.38 mg/kg. Both crops tended to take up Cd more effectively, and rice grains exhibited higher accumulation capacities of heavy metals in edible part than sugarcanes. Prediction models of Cd and comprehensive accumulation factors were established for rice and sugarcane, and different soil factors affect metal accumulation in crops cultivated in different types. Due to the exposure to As and Cd through rice consumption, non-carcinogenic risks are likely to occur in Liujiang residents.

The hazards of particulate matter (PM2.5) on human respiratory health have been previously reported. However, the molecular mechanisms underlying PM2.5-induced lung carcinogenesis have rarely been studied. In the present study, we explored the effects of PM2.5 on the epithelial-mesenchymal transition (EMT) and acquisition of cancer stem cell (CSC)-like properties in lung bronchial epithelial cells. We found that exposure of PM2.5 enhanced lung bronchial epithelial cell proliferation and EMT. In addition, the expression level of CSC-like biomarkers, CD133 and CD44, was significantly elevated by PM2.5 in vitro. Nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to participate in lung cancer. Loss of NEAT1 represses the malignant transformation of BEAS-2B and HBE cells induced by PM2.5. NEAT1 interacts with microRNA (miR)-582-5p, and miR-582-5p reverses the pro-tumor effects of NEAT1 overexpression. Hypoxia-inducible factor (HIF)-1α is an important transcription factor in the pathological responses to hypoxia. HIF-1α was a predicted target for miR-582-5p, and a direct correlation between them was identified. Inhibitors of miR-582-5p rescued HIF-1α expression, which was attenuated by a lack of NEAT1. In conclusion, PM2.5 increased NEAT1 expression, which, by binding with miR-582-5p, released HIF-1α and promoted EMT and the acquisition of CSC-like characteristics.

The present study investigated a wet mechanical pretreatment to improve methane production by anaerobic digestion from biowaste material by separating a biodegradable aqueous slurry fraction (ASF) from a more recalcitrant particulate fraction (PF). Four source-sorted municipal biowastes were studied, namely household (HBW), supermarket (SBW), restaurant (RBW), and green biowaste (GBW). The treatment consisted in soaking the waste in water and then pressing the slurry through a grid with 3-mm openings to separate the two fractions. Methane production of ASF and PF obtained from the four biowastes were measured using the BMP protocol and compared to the potential of the respective untreated biowaste. Results were very different for GBW as compared to the other three BWs. With GBW, which was the most lignocellulosic of the BW studied, only 17% of the initial methane potential was recovered in the ASF. The extraction was much better on the other biowastes and increased in the following order: HBW (58%) ≃ RBW (57%) < SBW (67%). The ASF from these biowastes exhibited low total solid contents and high BMPs (416, 408, and 423 NLCH₄.g⁻¹ᵥₛ for HBW, RBW, and SBW respectively). The experimental results obtained in this study therefore showed that wet pressing separation was an efficient pretreatment to improve and facilitate methane production by anaerobic digestion of biowaste such as HBW, RBW, and SBW.

The purpose of this research examination is to ascertain the effect of climate change, measured rainfall, temperature, and CO₂, on crop production by using data spanning from 1985 to 2016 in Somalia. ARDL bounds testing approach and Granger causality were employed to model the long-run and short-run cointegrations and the causality directions respectively of the scrutinized variables. The empirical results of the study found a long cointegration between the variables. It revealed that rainfall improves crop production in the long-run but hampers in the short-run, whereas temperature has adverse effect on crop production both in the long and short runs. But carbon dioxide emissions do not have any significant effect on crop production. Among other determinants, agriculture labour and land under cereal cultivation have a negative and positive impact on crop productivity in the long-run, respectively. In contrast, unidirectional causality is observed from agriculture and land under cereal cultivation to temperature, while another unidirectional causality is established from carbon dioxide emission to land under cereal cultivation. Hence, the policymakers should formulate coherent adaptation measures and mitigation policies to tackle the already felt effect of the changing climate on the agriculture sector to rebuild resilient and sustainable agriculture production in Somalia.

Corporate green innovation has played a crucial role in balancing profitability and environmental protection. The existing research on determinant factors of green innovation has its main defects in emphasizing excessively enterprise’s formal institutional environment and neglecting the informal institutional environment, causing an incomplete understanding of the relationship between institutional environments and corporate green innovation. To bridge this gap, using a sample of Shanghai and Shenzhen A-share listed firms in manufacturing industry during the period of 2010–2016, we investigate how social trust, an important informal institutions, affects corporate green innovation. Our results show that social trust is positively associated with green innovation, remaining valid after applying endogenous and robustness tests. In addition, the positive relationship between social trust and green innovation is more prominent when the enterprise is non-state-owned or locates in a looser command-and-control (CAC) environmental regulations region. Further analysis shows that social trust boosts corporate green innovation via promoting knowledge sharing, decreasing financing constraints, and fulfilling more corporate social responsibility (CSR). This paper enriches the literature concerning social trust and green innovation and draws back more public attention on the role of informal institutions play in promoting green innovation.

Industrial production creates material conditions for mankind, but also seriously pollutes the environment. In order to avoid pollution damage to the atmosphere, water, sound, and other environments, environmental impact assessments must be carried out before the project starts, and possible environmental pollution factors must be analyzed and predicted in advance. Company A, a manufacturer of mechanical parts, plans to build a new surface treatment production line, including two production links: anodizing and painting. The product coefficient method and the material balance method were used to evaluate and analyze the environmental pollution factors such as waste gas, wastewater, noise, solid waste, and discarded bath solution discharged during the operation period of the production line. The evaluation results show that after chromium mist recovery, spraying, filtration, and activated carbon adsorption and other measures are concentrated treatment, the concentration of various exhaust gas discharged in an organized manner is lower than the standard limit; various wastewater can be recycled after being filtered by ion exchange resin and activated carbon use, a very small amount of concentrated liquid needs to be handled by an external professional unit, and a cofferdam is installed under the production line and the ground is strengthened to prevent leakage, which will not pollute the groundwater environment; the noise level on the four plant boundaries during the operation of the production line meets the noise standard. No noise pollution will be generated; solid waste and discarded bath solutions are centrally stored by the enterprise and entrusted to an external professional unit for processing, and no other pollution will be generated.