Global Research in Environment and Sustainability

Subsidy Policies or Market Size? Exploring the Root Causes of China's EVs International Competitiveness

Chen, Ziqiu, Xiang, Hongjin — Sat, 03 Jan 2026 00:00:00 +0000

In recent years, the production and sales volume of EVs (EVs) in China have increased rapidly, but the origin of their international competitiveness is not clear, and there is a great debate. Firstly, this paper constructs a theoretical model of oligopoly competition in an open economy, and reveals the internal mechanism of market scale, subsidy policy, technological innovation and other factors affecting the international competitiveness of export products. Then, based on the reality of subsidies, sales and exports of EVs in China from 2018 to 2024, a data model was constructed to empirically test the theoretical analysis conclusions. The empirical results show that although government subsidies have promoted the development of China's electric vehicle industry in the initial stage, the domestic market size is the root cause of China's international competitiveness of EVs. Further mechanism analysis shows that economies of scale and technological innovation are two important ways for domestic market size to enhance the international competitiveness of China's EVs. Therefore, relying on the huge domestic market scale, promoting the reduction of the average cost and technological innovation of China's electric vehicle enterprises is the fundamental way to enhance the international competitiveness of China's EVs. This paper provides theoretical and empirical basis for how to enhance the international competitiveness of China's EVs.

Human Health Risk Assessment of Heavy Metals in Groundwater of Nasarawa West Senatorial Zone, Nasarawa State, Nigeria: Seasonal Dynamics, Exposure for Adults and Children, and Risk Mitigation Strategies

Chris-Onoh, C. O., Madu, P. C., Opaluwa, O. D., Aziagba, E. C. — Sun, 11 Jan 2026 00:00:00 +0000

This study evaluates human health risks posed by heavy metals in groundwater sources of Nasarawa West Senatorial District, Nigeria, focusing on eight priority metals: cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). Groundwater samples from 25 boreholes and 25 hand-dug wells across five LGAs (Karu, Keffi, Kokona, Nasarawa, Toto) were analyzed for metal concentrations in both dry and wet seasons. The results show widespread heavy metal contamination: for example, dry season lead levels averaged 0.36–0.56 mg/L in boreholes and 0.38–0.60 mg/L in wells (WHO limit 0.01 mg/L), and cadmium exceeded the 0.003 mg/L guideline in all samples (up to 0.055 mg/L in some wells). Seasonal trends indicate significantly lower metal concentrations in the wet season for boreholes (due to dilution and increased aquifer recharge), whereas shallow wells showed little to no improvement, hence heavy metal levels remained comparably high year-round. Health risk assessment was performed using USEPA methods for both carcinogenic and non-carcinogenic effects via ingestion. Hazard Quotients (HQ) and Hazard Index (HI) for non-cancer risk were calculated for adults and children; Cancer Risk (CR) was estimated for lifetime exposure to Cd, Cr(VI), Ni, and Pb. The findings reveal extremely elevated risk levels: adult HIs in dry season wells ranged up to ~43 (Nasarawa), and child HIs exceeded 200 in the worst-case scenario (Nasarawa dry wells), far above the safe limit of 1. Dominant contributors to HI were Ni and Cr, followed by Pb, while Cd, though present above guidelines, contributed comparatively less to HI. Carcinogenic risks were similarly high, for example, Cr(VI) in Keffi’s dry-season well water led to an estimated CR of ~2×10^-2 for children (20 times the 1×10^-4acceptable risk level). All sampled water sources showed cumulative cancer risks well above safe thresholds for both adults and children. This paper discusses the health implications of these findings, noting potential outcomes like neurological damage from chronic lead exposure and cancer risks from Cr and Ni. It also proposes mitigation strategies including source remediation (e.g., sealing off contaminated wells, treating mining effluents), household water treatment (advanced filtration for metals), and public health interventions to reduce exposure among vulnerable groups (especially children). The severity of heavy metal pollution in Nasarawa West’s groundwater calls for urgent action to protect community health and highlights the need for integrating water quality management into local mining and agricultural practices.

Stability of Porridge Produced from Stored Acha-Unripe Plantain Flour Blends Supplemented with Malted Soybean Flour

Thu, 29 Jan 2026 00:00:00 +0000

This study aimed to evaluate the quality attributes of flour blends and porridge produced from acha, unripe plantain, and malted soybean. The unripen plantain flour was substituted (0.5.10.15.20.25.30%) into the acha flour at the preliminary stage to determine the most preferred flour blends which formed the base of the research work. The most preferred flour blend of acha and unripen plantain (90:10) was supplemented with malted soybean flour (0,5,10,15,20,25,30%) to produce acha-unrippen-malted flour blends to produce light porridge. The porridge produce from 100% acha and the most preferred acha-unrippen plantain-malted flour blend porridge (60:25:15) were packaged and stored under atmospheric tempature for 6 weeks. The pH, acidity, peroxide values, free fatty acidity and sensory quality of the stored porridge were determinend weekly. The pH of acha flour and acha-unripe plantain and malted soybean flour blend increased from 7.15 to 7.55 and 6.60 to 7.65, respectively, TTA decreased from 0.89 to 0.80% and 1.13 to 0.85%, respectively, FFA increase from 0.43 to 0.64% and 0.54 to 1.17%, respectively, and PV increased from 2.40 to 4.90 and 3.30 to 8.30 meq/kg, respectively. The sensory properties of composite flour blend (60:25:15), such as appearance, aroma, taste and overall acceptability decreased from 7.55 to 5.45, 7.50 to 5.45, 7.25 to 5.15 and 7.40 to 6.30, respectively, with an increase in storage duration (0 – 6 weeks). The relative decrease in the assessed sensory quality and increase in the peroxide values with increase in storage duration showed the possibility in decrease in the quality of the stored porridge. However, the average means score for the general acceptability proved the acceptability of the same up to six weeks. It is recommended that this blend be adopted as a nutrient-dense food, with optimized packaging to improve shelf stability.

The Adsorption Potentials of Corn Cob for Oil Spill Clean Up

Alozie, A. C, P. C. Madu, S. S. Audu, O. Anifowose, C.O.Chris-Onoh, — Sun, 25 Jan 2026 00:00:00 +0000

Crude oil has great economic value, but not much have been said or done about oil spill impact to the environment. Its exploration has resulted in serious environmental pollution, ranging from air, water and soil. Oil spill throughpollution has introduced harmful or poisonous substance into the environment, causing adverse effects on living organisms and ecosystem. It is on record that global oil spill is about 400,000 (metric tonnes) taking place per year through various avenues. This problem of immediate need for effective oil spill remediation necessitated this study whereby corn cob, an agro-waste, biodegradable, can be deployed as sorbents for oil spill remediation and as substitutes for synthetic sorbents. The reason isthat inadequate method of immediate remediation for an oil spill has not been explored and most developed sorbents are not meeting up with the required efficacy of oil spill removal. The important contribution of this research to existing knowledge is that agro-waste possess greatadsorbing capabilities and pose no environmental hazard to the environment and can be converted or modified as adsorbent for oil spill clean-up, converting waste to wealth. Similarly, it substantiated the fact that corn cob has well documented capacity for oil sorption and the lack of dimensional stability due to associated hydroxyl functionality was corrected by modification. The adsorbent was subjected to sample preparation by washing, sun dried and crushed to a specific size. It was then oven dried at 350 ^o C and allowed to cool and subjected to FTIR analysis. It was subjected to modification by a reaction with acetic anhydride with sulpuric acid as catalyst. The modified adsorbent was subjected to crude oil recovery efficiency test. Sample characterization results showed moisture content of 1.600%, ash content of 3.860% and hausner ratio of 1.236. IR result indicated absence of spectra bands at 1740 -1745 cm^-1and 1020 -1040 cm^-1. The result of the oil removal efficiency was subjected to kinetic models.The high value of R²(0.985 for the pseudo second order, PSO and 0.9703 for the intra particle diffusion, IPD) obtained in the adsorption kinetics justifies the potency of corn cob as a sorbent in oil spill remediation. This work is also an indispensable reference and an essential reading for everyone concerned with oil spill cleanup in mangroves and wetlands, providing strategies for the conversion of agricultural wastes to effective oil spill sorbents.