Coal-based Power Research Articles

Provincial inequalities in life cycle carbon dioxide emissions and air pollutants from electric vehicles in China

It is still unclear whether emissions reductions from electric vehicles can be achieved across different regions from a lifecycle perspective. Here we use the life cycle assessment model and Quasi Input-Output model to evaluate the carbon dioxide emissions and air pollutants of internal combustion engine vehicles, plug-in hybrid electric vehicles, and battery electric vehicles in different provinces of China, with the provincial electricity consumption data and the sales data of electric vehicles. We find that battery electric vehicles have achieved 11.8% and 1.1% reduction in carbon dioxide and nitrogen oxide emissions, respectively, compared to internal combustion engine vehicles. In contrast, the emissions of sulfur dioxide and particulate matter 2.5 increased by 10% and 20%, respectively. Due to the coal-based power generation structure and the cold weather, the emission intensity of battery electric vehicles in most northern provinces is higher than that in southern provinces. From 2020 to 2030, improving technological progress and optimizing electricity mix will greatly assist in achieving emissions reduction. The results can help policy-makers better understand the emission characteristics and reasonably plan future emission reduction strategies in transportation.

A Study on Development in Engineering Properties of Dense Grade Bituminous Mixes with Coal Ash by Using Natural Fiber

Coal-based thermal power plants in India produce significant waste, primarily fly ash and bottom ash, which poses environmental and health risks when disposed of in large quantities. This research explores the effective use of these waste products in bituminous paving mixes, substituting natural aggregates to conserve resources. Dense-graded bituminous macadam (DBM) specimens were prepared using natural coarse aggregates, bottom ash as fine aggregate, and fly ash as filler, with sisal fiber as a reinforcing additive. Varying percentages (0–1%) and lengths (5–20 mm) of SS1 emulsion- coated sisal fiber were tested to optimize the mix’s engineering properties. VG30 bitumen, chosen for its superior Marshall characteristics, resulted in an optimum binder content of 5.57%, fiber content of 0.5%, and fiber length of 10 mm, achieving a Marshall stability of 15 kN. Additional performance tests, including moisture susceptibility, indirect tensile strength (ITS), creep, and tensile strength ratio assessments, confirmed that the coal ash and sisal fiber mix significantly enhances pavement durability. This approach offers an eco-friendly and economical solution for bituminous pavement construction, addressing coal ash disposal challenges and conserving natural aggregates. Keywords: Bottom ash, Fly ash, Sisal fiber, Emulsion, Indirect tensile strength, Static creep test, Tensile strength ratio.

Potentially toxic elements in fly ash bricks and associated ecological health risk: An opinionated review

Abstract Exposure to potentially toxic elements (PTE) from various sources seriously threatens the ecosystem in the modern era. Fly ash produced from coal and solid waste combustion contains a high concentration of PTE. Fly ash is a major by-product of coal-based thermal power plants and municipal solid waste incineration units. Due to the high demand for fly ash reuse due to its unique properties, fly ash is now in demand for manufacturing of various building materials and geo-liner for landfills. Brick is the primary building material used in construction. Fly ash bricks are very popular nowadays due to their low cost and high durability. This study reveals the ecological risk index through the exposure of heavy metals in fly ash reported in various studies. Results indicate extremely high ecological risk mainly due to Cd content in fly ash followed by Hg, As, Cu, and Pb. Fly ash is one of the causative agents for several diseases affecting the nervous system, skin, circulatory system, digestive system, reproductive system, and immune responses in the human body.

Comparative LCA of thermal power plant with CCS and solar PV system: sustainability assessment in Indian context.

The study's objective is to evaluate and compare the sustainability of power production techniques for India's transition to clean power generation. It specifically focuses on coal-based power generation with emission control technologies, flue gas desulfurization (FGD) with carbon capture and storage (CCS), and compares it with solar photovoltaic (PV) systems. The study conducted a life cycle assessment (LCA) to determine the environmental impact of electricity generation in each scenario. Inventory data has been collected for each case through plant visits, emission modelling, and literature searches. The study evaluated midpoint and endpoint impact indicators utilizing the ReCiPe (H) assessment methodology. The economic viability of all the cases was determined by calculating the levelized cost of electricity (LCOE). The results showed that retrofitting an existing power plant with flue gas desulfurization (FGD) and carbon capture and storage (CCS) reduced efficiency by 30%, required 1.2 times more auxiliary power, and increased heat rates. The LCA results showed that the global warming potential (GwP) for FGD and CCS together was 0.614 kg CO2 eq. per kWh of power generation. On the other hand, the GwP for the solar PV system was much lower, at 0.043 kg CO2 eq. per kWh. There were trade-offs in both cases, but solar PV plants are more environmentally friendly than thermal power plants equipped with CCS systems in almost all categories. Furthermore, the LCOE results showed Rs 3.87 per kWh for an on-grid solar PV plant and Rs 5.33 for thermal power, with CCS and FGD showing solar as an economically more feasible option. Retrofitting thermal power facilities with emission control technology is necessary to achieve net zero emissions, but transition torenewable energy sources isinevitable.

CO2-selective membrane reactor process for water-gas-shift reaction with CO2 capture in a coal-based IGCC power plant

Integrated gasification combined cycle (IGCC) power plants enable pre-combustion carbon capture to reduce CO2 emissions. Membrane water-gas-shift (WGS) reactors can intensify these processes by converting raw syngas to H2 with simultaneous CO2 capture in one unit. This paper reports process design and techno-economic analysis (TEA) for a membrane reactor (MR) process with a CO2 selective ceramic-carbonate dual-phase (CCDP) membrane for WGS reaction with CO2 capture for a IGCC power plant. The target performance includes CO conversion > 95 %, hydrogen purity > 90 %, CO2 purity > 95 %, and carbon capture > 90 %. Using a commercial catalyst and a CCDP membrane, the MR can achieve the performance target at 750 °C and space velocity of 250 h−1. The outcome of the process design and TEA shows that the CCDP MR has an operating cost of $24 M/year, significantly lower than that for the conventional processes (40 M$/year). However, the MR process has a higher capital cost ($1007 M) than the conventional process ($527 M) because of the higher cost of the CCDP MRs. Modeling analysis shows a MR with higher CO2 permeance can deliver the target at a higher space velocity and lower membrane surface area to catalyst volume ratio, leading to a significantly reduced MR capital costs.

Multi-faceted sustainability improvement in low voltage power distribution network employing DG and capacitor bank

Efficient distribution of active and reactive power in distribution networks is crucial for ensuring that consumer demand is met and that electrical power quality is maintained. This requires careful planning, particularly in terms of optimally placing and sizing distributed generator (DG) and capacitor bank (CB) units. These units play a key role in minimizing power losses and voltage fluctuations within the network. However, implementing DG and CB units in unbalanced distribution networks presents unique challenges due to inherent system unbalances. To address these challenges, this article proposes a method for allocating and sizing DG and CB units in unbalanced distribution networks. The approach accounts for the network's unbalance and targets multiple objectives, such as reducing power losses, improving multi-phase voltage stability, and minimizing phase-to-phase voltage unbalance. The fast and flexible radial power flow (FFRPF) technique is employed to model complex interactions and constraints within the network, leading to a multi-objective optimization problem. This optimization problem is solved using the weight aggregated particle swarm optimization (WA-PSO) method, a variant of particle swarm optimization tailored for multi-objective functions. WA-PSO simplifies the process by combining multiple objectives into a single function using weighted aggregation. The efficacy of this approach is validated on 19, 34, and 123-node unbalanced radial distribution networks (URDNs). The results show significant improvements in power delivery efficiency across all tested networks, especially when DG and CB units are operated simultaneously. Specifically, DG and CB integration led to a reduction in system losses by 89.90 %, 88.42 %, and 86.87 %, and a decrease in three-phase voltage unbalance indices by 88.75 %, 81.68 %, and 39.05 %, for the 19, 34, and 123-node systems, respectively, while maintaining voltage stability within acceptable limits. Additionally, CO2 emissions were reduced by 52 %, 62 %, and 53 % when microturbines were utilized instead of coal-based thermal power plants, further highlighting the environmental benefits of the proposed approach.

Symposium Review: Exploring the role of geosciences in carbon storage

Carbon capture and storage (CCS) is crucial for clean energy transitions, yet its adoption in Southeast Asia has been slow. In India, the drive for sustainable energy and CCS research intensified after the prime minister set a net-zero target of 2070. Major industries (e.g., steel, cement, and coal-based power plants)have been encouraged to adopt sustainable practices. India is developing domestic CCS capabilities and is open to importing proven technologies.

Environmental Implications of Fly Ash Management and Utilization: A Review of Laws, Policies, and Practices.

In the environmental realm, ‘fly-ash’ refers to the byproduct of burning pulverized coal in thermal power stations. One of India's most resource-intensive and polluting industries, coal-fired power generation, contributes considerably to atmospheric pollution. Public power stations that use coal or lignite to generate energy account for 77% of the nation's total electricity production. This sector is responsible for over 65% of India's total coal use. This study employs a multifaceted approach combining theological, exploratory, analytical, and descriptive methods. It relies on secondary sources from diverse web resources to analyze fly ash's ecological and health impacts, explore utilization methods, and discuss potential legislation to prevent careless disposal. The coal-based power industry has added 32 GW, or over 64% of the new massive capacity, to its operations in the last decade, leading to a rise in coal consumption. There was a greater than 71% increase in annual coal usage, from 367 million tonnes in 2009–10 to almost 629 million tonnes in 2018–19. The increasing usage of coal in India has led to fly ash being one of the country's most significant industrial solid wastes. Fly ash is a residue or byproduct made when coal is burned; it is harmful to both humans and the environment. The problem is particularly acute in India because of the poor calorific value, high ash content, and low grade of the coal used there.

Valorization of food waste into hydrogen energy through supercritical water gasification: Generation potential and techno-econo-environmental feasibility assessment

Food waste (FW) is a significant portion of the solid waste produced by cities, and it has become a global problem due to the poor management of food distribution and consumption. The improper disposal of FW in landfills precipitates pervasive global environmental predicamentsHowever, effective management strategies have the potential to convert this large amount of garbage into a very effective renewable energy source, particularly through the generation of environmentally friendly hydrogen. This study examines the capacity for energy generation and the practicality of hydrogen production in Bangladesh using supercritical water gasification technology. The findings indicate that approximately 489 MW of electricity can be extracted from approximately 23 million tons (Mt) of FW in 2023, with a projected escalation to around 2042 MW by 2042, coinciding with an anticipated surge in FW generation to approximately 110 Mt. Moreover, the study delves into the economic feasibility of these gasification endeavors, employing diverse metrics encompassing total life cycle cost, net present value, investment payback duration, levelized cost of energy, and internal rate of return. Technoeconomic analyses divulge an investment with a net present value of 11,669.4 M$M$, an 11-year payback period, and an internal rate of return of 14 %. In addition, the research assesses the technological, economic, and environmental viability inherent in the establishment of gasification-based electricity-generating facilities in Bangladesh's preeminent eight cities by 2023. This examination postulates that a transition from coal-based power plants to those powered by food waste would precipitate an annual reduction of 3.59 Mt in carbon dioxide emissions.

Environmental, technological, and economic analysis of supercritical coal-fired power system.

Developing countries primarily rely on fossil-based energy sources to meet their energy demands. The use of fossil fuels has several adverse environmental repercussions that damage the biosphere both directly and indirectly. Among fossil fuels, coal brings about the heaviest environmental externalities, yet its abundance makes its use widespread, particular in countries having significant power generation deficits, such as Pakistan. This study presents an environmental, technological, and economic analysis of a supercritical coal-based power unit located in Pakistan and used for electricity generation. For environmental assessment, the CML-1A baseline method in OpenLCA software was used, and eight midpoint impact indicators were selected. The functional unit chosen was 1 MWh of generated electricity. The results indicated that the category of ozone layer depletion has the least impact, whereas global warming potential has the highest impact score. Except for photochemical oxidation and human toxicity, the plant operational stage dominated most of the selected impact categories. The current paper also reveals that the removal efficiency of CO2 and other pollutants is higher in supercritical compared to subcritical plants. Moreover, the economic feasibility of supercritical plant is compared with chemical looping combustion (CLC)-based supercritical coal-fired power plant, and results shows that CLC-based coal-fired power plant is a more competitive and environmentally friendly option. The utilization of a scientific cleaner energy-management system in real-time, as exemplified in this study, may facilitate the development of a optimalpolicy framework that encouragesfor the adoption of cleaner coal power generation in developing countries, ultimately resulting in improved energy sustainability. Furthermore, this paper also presents some policy implications which could be helpful for policymakers, researchers, and industrialists to improve the sustainability of energy in emerging economies.

Understanding physiological, elemental distribution and bioaccumulation responses of crustose and foliose lichens in the vicinity of coal-based thermal power plant, Raebareli, Uttar Pradesh, India

Environmental pollution, especially from coal-based thermal power plants, poses significant risks to human respiratory health and the environment. This study evaluates the diversity of lichens in the areas. Physiological and bioaccumulation responses of two crustose lichens (Bacidia incongruens and Rindoina sophodes) and one foliose lichen (Pyxine cocoes) in the vicinity of the Feroz Gandhi Unchahar National Thermal Power Corporation, Raebareli, Uttar Pradesh, India were also assessed. These lichens, exposed to emissions including fly ash, greenhouse gases, metals, and particulate matter were analyzed for metal accumulation and physiological responses. Changes in physiological parameters and metal profiles concerning distance from the coal-based thermal power plant to the outskirts were analyzed for B. incongruens, R. sophodes and P. cocoes by utilizing Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The study identified 18 lichen species from 12 genera and 10 families in the area, with Pyxine sorediata newly recorded in Uttar Pradesh. The dominant species, B. incongruens, P. cocoes, and R. sophodes, preferred substrates like Mangifera indica, Acacia nilotica, and Azadirachta indica bark. Physiological analyses revealed variations in pigment concentrations, with significant differences in chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and chlorophyll degradation, while protein content remained stable. Metal accumulation studies showed nine metals with distinct patterns, B. incongruens had higher concentrations in the west (52730.61 µg g-1) and P. cocoes in the east (23628.32 µg g-1). Correlation analyses indicated significant relationships between paired elements, suggesting specific sources of environmental contamination. This research highlights the significance of integrating physiological and environmental factors to understand lichen responses to coal based thermal power plant.

Investigation of co-combustion characteristics and kinetics of low-ranked coal and hydrochar derived from cow manure

CO2 emission should be reduced by the effective utilization of low-ranked coal in a coal-based power plant based on co-combustion of coal and biomass. This study investigated the co-combustion behavior of lignite and cow manure using three different kinds of samples: raw lignite coal blended with cow manure (CM-L), raw lignite coal blended with hydrochar derived from cow manure (HCM-L), and co-hydrothermal carbonization (Co-HTC) of lignite coal and cow manure (Co-HCML) using thermogravimetric analysis and a hydrothermal carbonization (HTC) temperature of 200 °C for 60 min. The kinetic parameters were calculated and analyzed using the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods. The combustion characteristics were studied of the various kinds of hydrochar mixed with lignite coal. The results showed that the low-ranked coal improved the fuel properties by increasing carbon content and decreasing sulfur through the HTC processes. The activation energy of Co-HCML was the lowest, which is preferable, and therefore it was recommended as the promising process.

Internal Erosion Induced Instability of Coal Ash Ponds: Forensic Analysis using Smoothed Particle Hydrodynamics (SPH)

Coal-based power generation will continue to be the backbone of energy supply until renewable energy sources become mainstream. Hence, management of large quantities of coal ash generated as a by-product is a global concern. Coal ash is commonly disposed in ash ponds and is prone to internal erosion because of low specific gravity. The consequent breach of an ash pond may result in severe socioeconomic impacts. Thus, design and analysis techniques incorporating internal erosion are essential for constructing resilient ash ponds. This study investigates the effect of internal erosion on the stability of ash ponds using a five-phase SPH model. The approach is utilised for analysing an operational ash pond from India, where instability due to internal erosion was observed. The results indicate that the amount of erodible fly ash significantly influences the initiation of instability and the subsequent mass flow, with close to 100 % reduction in mass flow as the fly ash content is reduced from 80 % to 20 % by weight. The study also highlights the significance of appropriate coal ash slurry disposal practices and field monitoring for averting such failures. Further, replacing the erodible coal ash with a non-erodible material is validated as a feasible failure mitigation measure.

Comparative Analysis of Single Stage and Dual Stage PV Based Generation System for Pollution Reduction in Asian Nations

The growing need for sustainable and clean energy solutions has elevated photovoltaic (PV) systems to the forefront of competitive options. In order to evaluate the performance and viability of single-stage and dual-stage single-phase PV voltage source inverter systems within the context of renewable energy, this study undertakes a thorough comparative analysis. MATLAB Simulink has been used to run the simulations, and the results produced show that the selected configurations are robust and closely match theoretical expectations. The study explores the subtle distinctions, benefits, and drawbacks that come with single- and dual-stage systems. By extensively evaluating the consequences on system stability, grid synchronisation, and power quality, useful insights emerge. The simplicity and efficiency of the single-stage system are demonstrated by the direct connectivity between the PV MPPT output and the inverter. In contrast, the dual-stage system addresses the issue of low PV output voltage by incorporating a boost converter with an MPPT algorithm, albeit at the expense of more parts and complexity. The research described here adds a great deal to the current discussion on PV system optimization. The study notably clarifies methods for improving dependability and efficiency in applications involving renewable energy. With the increasing worldwide trend towards sustainable energy, it is critical to comprehend the subtle dynamics of various PV setups. In addition to offering a comprehensive grasp of the complexities involved in single- and dual-stage single-phase PV voltage source inverter systems, this research paves the way for future developments in the planning and execution of effective renewable energy solutions especially for Asian nations that still rely on coal-based power plants. Increased contribution of solar based electricity generation will lead to a significant drop in pollution contributed by the ash and gases released by thermal power plants that employ fossil fuels. The ultimate goal of this study is to provide information to stakeholders in the renewable energy industry so that they may make more informed decisions and create PV systems that are both sustainable for the environment and efficient for the utility.

Thermoeconomic analysis of organic Rankine cycle with different working fluids for waste heat recovery from a coal-based thermal power plant

Thermoeconomic analysis of organic Rankine cycle with different working fluids for waste heat recovery from a coal-based thermal power plant

Design Of Tangentially Fired Pulverized Coal Burner Nozzle For Enhanced Erosion Resistance

Erosion-induced failure of pulverized coal burner nozzles (PCBN) presents a significant challenge in pulverized coal-based thermal power plants. Investigations have identified multiple causative factors leading to the accelerated degradation and consequent reduced lifespan of PCBN. These factors include the erosive impact of solid fuel particles carried at high velocities and angles, as well as the high-temperature conditions within the combustion zone. To mitigate erosion, strategies often revolve around enhancing material resistance or optimizing aerodynamic profiles to minimize drag forces. This study employs Computational Fluid Dynamics (CFD) via the CFX code to model and analyze the erosion dynamics within PCBN. By adjusting the geometry of the inner plates within the PCBN, simulations indicated a notable improvement in erosion resistance. The optimized design achieved this by expanding the flow area between the innermost bifurcated plates without altering their angle, leading to a more uniform flow distribution and favorable velocity and pressure gradients. These modifications have the potential not only to prolong nozzle life but also to contribute to more efficient combustion in tangentially fired furnaces.

Driving factors analysis and scenario prediction of CO2 emissions in power industries of key provinces along the Yellow River based on LMDI and BP neural network

IntroductionPower industry is one of the largest sources of CO2 emissions in China. The Yellow River Basin plays a supportive role in guaranteeing the effective supply of electricity nationwide, with numerous power generation bases. Understanding the drivers and peak of CO2 emissions of power industry in the Yellow River Basin is vital for China to fulfill its commitment to reach carbon emissions peak by 2030.MethodsThe Logarithmic Mean Divisia Index (LMDI) model was employed to explore the drivers to the change of CO2 emissions in power industries of three study areas, including Inner Mongolia Autonomous Regions, Shanxi Province, and Shandong Province in the Yellow River Basin. And Back Propagation (BP) neural network was combined with scenario analysis to empirically predict the trend of the amount of CO2 emitted by power industry (CEPI) from provincial perspective.ResultsCEPI in Inner Mongolia under the scenarios of a low degree of CO2 emissions promotion with a medium degree of CO2 emissions inhibition (LM) and a low degree of CO2 emissions promotion with a high degree of CO2 emissions inhibition (LH) scenario can reach a peak as early as 2030, with the peak value of 628.32 and 638.12 million tonnes, respectively. Moreover, in Shanxi, only CEPI under a low degree of CO2 emissions promotion scenarios (LL, LM, LH) can achieve the peak in 2025 ahead of schedule, with amounts of 319.32, 308.07, and 292.45 million tonnes. Regarding Shandong, CEPI under scenarios of a low degree of CO2 emissions promotion with a high degree of CO2 emissions inhibition (LH) and a medium degree of CO2 emissions promotion with a high degree of CO2 emissions inhibition (MH) could achieve the earliest peak time in 2025, with a peak of 434.6 and 439.36 million tonnes, respectively.DiscussionThe earliest peak time of CEPI in Shandong Province and Shanxi Province is 2025, but the peak of CEPI in Shanxi is smaller than that of Shandong. The peak time of CEPI in Inner Mongolia is relatively late, in 2030, and the peak is larger than that of the other two provinces. The per capita GDP is the most positive driving factor that contributes to the CEPI. Shandong has a strong economy, and its per capita GDP is much higher than Shanxi’s. Therefore, even under the same peak time, the CEPI in Shandong is much higher than that of Shanxi. Inner Mongolia is extensive and sparsely populated, which makes its per capita GDP rank among the top in China. In addition, Inner Mongolia’s coal-based power generation structure and high power generation also contribute to its late CO2 peak time and large CO2 peak.

Lost Futures

Embedded within large-scale resource extraction projects is a tension between the immobility of the resource and the mobility of the people who inhabit the surface over which the resource is found. The limited ability to negotiate the place of extraction, and the destruction of prior ecologies, can generate significant hardship to local populations and pose particular ethical dilemmas, as in the small village of Wollar located at the New South Wales coal frontier. Here, the supposed ethical imperatives of coal-based power and energy have dismantled and sacrificed communities as the coal mining industry has advanced and intensified its operations. Looking at both social and environmental ecologies, the paper analyses how imagined coal-centred futures, and progress, is phrased (or not phrased) as an ethical and political issue, and the consequences of that coal-based future, psychologically, emotionally, imaginally and cosmologically on those who live near the mines. What once carried a felt ambience of being home has, through technological and political deployment, become a non-place of transience, anonymity, and change. In this unbalanced political conflict, a natural environment and lived ecology are subject to developmentalist and technological ecologies in ethical-political dispute with a diminishing sense of home, and produce suffering because of unequal power relations which derive from the success of the destructive technologies. Searching for a language to capture the sense of sacrifice and suffering that happens in the shadow of large-scale mining, I propose a new concept: ‘eritalgia’. Eritalgia expands the existing duad of nostalgia and solastalgia, capturing the sense of lost future self in place, emphasising the role of power and discursive hegemony in shaping experiences of and well-being in place.

Evaluating the effect of fly ash on soil properties and germination of rice (Oryza sativa): A study on the utilization of thermal power plant residue

India has a power capacity of 4,02,817 MW, with over half coming from coal-based thermal power plants like the Kolaghat Thermal Power Plant (KTPP), West Bengal, India. These plants produce harmful fly ash, requiring safe disposal. KTPP alone generated 0.5921 million tons of fly ash in 2020-21, managed using ash ponds. Concerns have arisen regarding contamination of nearby agricultural fields, impacting rice cultivation. The objective of the study was to understand how fly ash affects soil and seed germination and emphasizes the importance of making careful decisions when using industrial residues in agriculture to ensure sustainable and responsible practices that prioritize environmental health and plant well-being.Samples were collected from areas near KTPP, and plant growth substrates were prepared by mixing control soil with varying fly ash concentrations. The study was conducted between 15 February and 19 May 2023 in PnaskuraBanamali College (Autonomous), Purba Medinipur, West Bengal, India. The physical and chemical properties of these substrates were analyzed, and rice seed germination studies were carried out over 30 days. The subsequent transplantation and growth assessments included measuring shoots and roots, analyzing leaf chlorophyll and carotenoids, and conducting statistical evaluations. The experiments were triplicated, and statistical analyses using SPSS 16 indicated statistical significance at p less than 0.05.The study helps to understand how fly ash affects soil and seed germination, revealing both positive and negative effects on soil properties and plant growth. It emphasizes the need for careful decision-making when using industrial residues in agriculture to ensure sustainable and responsible practices that prioritize both environmental health and plant well-being.

Long-term PM2.5 exposure is associated with asthma prevalence and exhaled nitric oxide levels in children.

Exhaled nitric oxide concentration (FENO) is a marker of airway inflammation. This study aimed to evaluate the association of air pollution exposure with FENO levels and asthma prevalence with respiratory symptoms in school children. We analyzed 4736 school children who reside in six townships near industrial areas in central Taiwan. We evaluated asthmatic symptoms, FENO, and conducted the environmental questionnaire. The personal exposure of PM2.5, NO, and SO2 was estimated using land-use regression models data on children's school and home addresses. Annual exposure to PM2.5 was associated with increased odds of physician-diagnosed asthma (OR = 1.595), exercise-induced wheezing (OR = 1.726), itchy eyes (OR = 1.417), and current nasal problems (OR = 1.334) (P < 0.05). FENO levels in the absence of infection were positively correlated with age, previous wheezing, allergic rhinitis, atopic eczema, near the road, and for children with high exposure to PM2.5 (P < 0.05). An increase of 1 μg/m3 PM2.5 exposure was significantly associated with a 1.0% increase in FENO levels for children after adjusting for potential confounding variables, including exposures to NO and SO2. Long-term exposures to PM2.5 posed a significant risk of asthma prevalence and airway inflammation in a community-based population of children. Annual exposure to PM2.5 was associated with increased odds of physician-diagnosed asthma and nasal problems and itchy eyes. Long-term exposures to PM2.5 were significantly associated with FENO levels after adjusting for potential confounding variables. This is first study to assess the association between FENO levels and long-term air pollution exposures in children near coal-based power plants. An increase of 1 μg/m3 annual PM2.5 exposure was significantly associated with a 1.0% increase in FENO levels. Long-term exposures to PM2.5 posed a significant risk of asthma prevalence and airway inflammation in a community-based population of children.