Emission Factors Research Articles

Characterization and quantification of atmospheric emissions of dioxins, dl-PCBs and polycyclic aromatic hydrocarbons from municipal solid waste open burning in Southeast Asia.

Characterization and quantification of atmospheric emissions of dioxins, dl-PCBs and polycyclic aromatic hydrocarbons from municipal solid waste open burning in Southeast Asia.

Dynamically predicting nitrous oxide emissions in a full-scale industrial activated sludge reactor under multiple aeration patterns and COD/N ratios.

Dynamically predicting nitrous oxide emissions in a full-scale industrial activated sludge reactor under multiple aeration patterns and COD/N ratios.

High-resolution inventory of polycyclic aromatic hydrocarbon emissions from wildfires in China.

High-resolution inventory of polycyclic aromatic hydrocarbon emissions from wildfires in China.

Harmonizing soil carbon simulation models, emission factors and direct measurements used in LCA of agricultural systems

Harmonizing soil carbon simulation models, emission factors and direct measurements used in LCA of agricultural systems

Emission and risk of atmospheric hexachlorobutadiene might be underestimated globally.

Emission and risk of atmospheric hexachlorobutadiene might be underestimated globally.

Quantifying, predicting, and mitigating nitrous oxide emissions in a full-scale partial nitritation/anammox reactor treating reject water.

In this paper, a set of mathematical tools are developed and assembled to quantify, predict and virtually assess N2O emission mitigation strategies in partial nitritation (PN) / anammox (ANX) granular based reactors. The proposed approach is constructed upon a set of data pre-treatment methods, process simulation models, control tools (and algorithms) and key performance indicators to analyze, reproduce, and forecast the behavior of multiple operational variables within aerobic granular sludge systems. All these elements are tested on two full-scale data sets (#D1, #D2) collected over a period of four months (Sept-Dec 2023). Results show that data pretreatment is essential for noise reduction, filling data gaps, and ensuring smooth process simulations. The model accurately predicts (normalized RMSE< 1) multiple N oxidation states (NHx, NO2-, NO3-, N2O) and dissolved oxygen (DO), demonstrating its capability to describe bacterial behavior within the studied system. Special emphasis is placed on weak acid-base chemistry where pH is reliably reproduced, and it can be used for control purposes. Both biological and physico-chemical aspects are predicted at different time scales (months, days, minutes). While nitritation mainly occurred in the bulk, biofilm distribution showed inactive inner granule parts and increasing biomass (mostly ANX) towards the surface, with distinct organic concentrations. Gradients for multiple soluble compounds could also be reflected. Nitrifier denitrification (ND) is identified as the main N2O production pathway. The model revealed that the system was suffering from low ANX activity leading to NO2- accumulation. This in combination with low DO levels resulted in an unusually high emission factor (EF). The validation data set also yielded satisfactory results (normalized RMSE< 1). The scenario analysis revealed that modification of the operational parameters could improve the ANX activity and lead to N2O emission rates that are in line with what is normally expected from similar systems. The study includes a discussion on transitioning from process models to digital shadows/ twins for real-time process monitoring. Additionally, it emphasizes the necessity of evaluating reject water technologies from a plant-wide perspective.

Regional carbon emission efficiency analysis and factor decomposition: Cases from South Korea

Regional carbon emission efficiency analysis and factor decomposition: Cases from South Korea

Road Transport and Urban Mobility Greenhouse Gas Emissions Factor for Air Pollution Modeling in Burkina Faso

Road Transport and Urban Mobility Greenhouse Gas Emissions Factor for Air Pollution Modeling in Burkina Faso

Development of real-road CO2 emission factors for diesel light-duty vehicles across diverse driving conditions

Development of real-road CO2 emission factors for diesel light-duty vehicles across diverse driving conditions

Patient transit and radiotherapy: Cost-effectiveness approach to environmental health savings.

e23146 Background: Environmental pollution and climate change exacerbate risks for cancer patients, potentiating carcinogenesis, respiratory illness, and cardiovascular disease. Hospital-sponsored patient transit presents an area to reduce healthcare’s emissions. Our recent study with Uber Health transitioning to electric [EV] or hybrid vehicles for patient radiotherapy (RT) transport achieved greenhouse gas (GHG) reductions without significantly increasing costs. 1 Clinically equivalent hypofractionated (HP) RT schedules (fewer, higher-dose sessions) may also reduce harmful emissions by 42–77%. 2 We use a cost-effectiveness framework to evaluate the combined impact of EV transit and HP RT on GHG-related health outcomes (disability-adjusted life-years [DALYs]) and transit costs. Methods: We analyzed 2024 Uber Health data from 5,063 rides (237 patients) to calculate transit costs for EVs and gas cars and roundtrip distances to RT (avg: 10.1 mi). 1 Using EPA/DOE emission factors for private vehicles (EV: 0.40, gas: 0.076 kgCO₂e/mi), we estimated GHG emissions per RT course. DALY losses from GHG emissions were calculated with validated conversion factors. 2 Scenarios were modeled for conventional (25 fractions (fx)), HP (15 fx), and ultra-HP (5 fx) RT schedules for breast cancer; incremental cost-effectiveness ratios (ICERs) represented ∆cost/∆DALY. Results: Interventions incorporating HP or ultra-HP for breast cancer were all cost-saving (Table 1). Switching to HP reduced transit-related costs by ~$400 per patient, and adding EV transit doubled DALY savings versus gas. Ultra-HP courses saved ~$800 per course, with EV transit increasing DALY savings by 20%. For conventional courses, EV (vs. gas) yielded an ICER of $5,384, demonstrating cost effectiveness under willingness-to-pay thresholds valuing a DALY at least $5,000. Conclusions: Integrating EV-based patient transit with HP RT may allow cancer care centers to minimize GHG-associated health risks while maximizing cost savings. This potentially scalable model aligns quality care and patient access with environmental stewardship and resource optimization. Future analyses should include patient/staff experiences and oncologic outcomes.

Towards objective evaluation of the accuracy of marginal emissions factors

Towards objective evaluation of the accuracy of marginal emissions factors

Application of LED-based degradation technology for harmful substances during the growing to finishing stages in an enclosed water-curtain-type SPF pig farm

Effective cleaning and disinfection practices are essential in pig farming to prevent the spread of infectious agents. However, conventional detergents and disinfectants may leave residues that harbor microorganisms, pose toxicity risks to pigs, and negatively impact the environment. To address these concerns, this study investigated the use of a novel, non-chemical degradation technology based on light-emitting diode (LED) systems in the farrowing area of an enclosed, water-curtain-type specific pathogen-free (SPF) pig farm. New-generation hazardous-substance-reducing LED lights were installed in the facility, resulting in significant reductions in airborne bacterial counts and concentrations of harmful gases, including ammonia (NH₃) and ethylene (C₂H₄), as well as fine particulate matter (PM2.5 and PM10). Laboratory-based assays further confirmed that these LED systems effectively inhibited the replication of porcine reproductive and respiratory syndrome virus (PRRSV), highlighting their potential for disease prevention in swine production. Energy consumption analysis revealed that each 4-foot LED unit consumed only 15.8 W of electricity, in contrast to the 40 W consumed by the previously used fluorescent lights. With 54 LED units operating 9 hours daily, the annual energy saving was calculated to be 4,292.8 kWh. According to the latest national emission factor (0.494 kg CO₂e/kWh), this corresponds to an annual reduction of approximately 2.12 metric tons of carbon emissions. These findings demonstrate that hazardous-substance-reducing LED technology not only improves the hygienic and environmental conditions in pig farms but also contributes to energy conservation and carbon reduction goals. This innovation holds substantial potential for sustainable and net-zero carbon livestock farming.

Light Absorption and Chromophore Characteristics of Brown Carbon in PM Emitted From Agricultural Machinery in China

AbstractThe extensive utilization of agricultural machinery in China has made it a prominent contributor to particulate matter (PM). However, there still exist significant knowledge gaps in understanding optical characteristics and molecular composition of chromophores of brown carbon (BrC) in PM emitted from agricultural machinery. Therefore, BrC in PM from six typical agricultural machines in China were measured to investigate the light absorption, chromophore characteristics, and influencing factors. Results showed that the average emission factors of methanol‐soluble organic carbon (MSOC) and water‐soluble organic carbon (WSOC) were 0.96 and 0.21 g (kg fuel)−1, respectively, exhibiting clear decreasing trends with increasing engine power and improving emission standards. Despite the light absorption coefficient of methanol‐extracted BrC (Abs365,M) being approximately 2.2 times higher than that of water (Abs365,W), mass absorption efficiency of water‐extracted BrC (MAE365,W) exhibited significantly greater values than MAE365,M. Among the detected chromophores, nitro‐aromatic compounds (NACs) exhibited the highest contribution to light absorption that was about 14.5 times more than to total light absorption compared to their mass contributions to MSOC (0.04%), followed by polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs). Besides, the average integrated simple forcing efficiency values were estimated to be 1.5 W g−1 for MSOC and 3.7 W g−1 for WSOC, indicating significant radiative forcing absorption of agricultural machinery. The findings in this study not only provide fundamental data for climate impact estimation of but also propose effective strategies to mitigate BrC emissions, such as enhancing emission standards and promoting the adoption of high‐power agricultural machinery.

Greenhouse gas emissions and economic performance of Canadian cow-calf farms

The study aimed to quantify financial performance, greenhouse gas (GHG) emissions, and identify relationships between the two in Canadian cow-calf operations. Benchmark farms (n=62) were established from 225 cow-calf operations grouped by similar management systems (calving date, weaning date, herd size, winter feedstuff, and winter feeding days). Emissions were estimated using a whole farm emissions model (Holos), and emission factors for canola meal, protein supplements and minerals, expressed in kg CO2e per liveweight (LW) sold (emission intensity, EI). For economic analysis, the Agri-benchmark model was used to evaluate financial performance. Based on EI, the top and bottom 25% quartiles were designated as the high EI (HEI) and low EI (LEI) farms, respectively. The mean EI was 38.4 kg CO2e/kg LW in HEI and 23.1 kg CO2e/kg LW in LEI. The LEI farms had a higher (P&lt;0.01) revenue, related to LW output. Cluster analysis indicated the LEI farms were associated with greater medium term profit, revenue, cull cow percentages, calf weaning weight and average daily gain. Some HEI farms were associated with direct and indirect N2O emissions, while others with enteric and manure CH4, and energy CO2. Improving productivity and lowering depreciation cost simultaneously improves GHG and economic efficiency of farms.

Effect of operating conditions and technology on residential wood stove emissions of criteria, greenhouse gas, and hazardous air pollutants

ABSTRACT Residential wood heating (RWH) is a known source of particulate matter (PM), hazardous air pollutants (HAPs), and greenhouse gases (GHGs). However, the influence of operating conditions on emissions from certified cordwood stoves in the United States (U.S.) remains poorly understood. This study analyzes emissions data from different operational phases, including start-up, high heat, and low heat, to improve indicators of real-world stove performance. We tested five commercially available U.S. stoves through the four distinct operational conditions or phases of the novel Integrated Duty Cycle (IDC) testing protocol, which simulates typical residential wood-burning patterns by incorporating start-up, high heat, medium (or “maintain”) heat, and low heat (“overnight” burn) phases. We determined emissions factors (EFs) by IDC phase for criteria, GHG, and HAP compounds, including volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). We also developed a multiple linear regression model to assess the effect of dry burn rate (DBR) and IDC phase on each pollutant EF by stove technology type. IDC phase significantly influenced (p < 0.01) pollutant EFs from uncertified stoves and most emissions from catalytic/hybrid stoves, while DBR played a more substantial role in emissions from non-catalytic stoves. Current stove certification methods rely on a single nominal load under steady-state combustion, which does not reflect typical residential use. Additionally, we found DBR to be an inconsistent predictor of emissions in cordwood stoves. These findings underscore the importance of stove technology and operating conditions in determining RWH emissions, with implications for air quality science and regulatory policy. Implications: We report cordwood stove emissions factors by operating condition using the novel Integrated Duty Cycle (IDC) protocol on various U.S. technologies meeting 2020 New Source Performance Standards (NSPS) and one pre-NSPS, circa 1980 stove. We determined significant effects from IDC operating phase on uncertified and catalytic/hybrid stove emissions, but not noncatalytic stoves. This has important implications for use of emissions factors in air quality science, policy, and stove design, as different U.S. climate zones will influence the number of stove start-ups, fuel loading patterns, and frequencies of other “real world” operating conditions such as “high heat” and “overnight burn.”

Life Cycle Cost and Environmental Performance of Electric and Gasoline Vehicles in Cold Climate and Coal-Dependent Regions: A Case Study of Heilongjiang Province, China

This study conducts a comparative life cycle assessment (LCA) and life cycle cost (LCC) analysis of battery electric vehicles (BEVs) and gasoline vehicles (GVs) in Heilongjiang Province, China, under cold climate conditions and a coal dominated electricity grid. Environmental impacts were assessed using SimaPro with the ReCiPe 2016 Midpoint (H) method, while cost performance was evaluated over 5-, 10-, and 15-year ownership periods. Results show that BEVs offer lower total ownership costs than GVs, even without subsidies, primarily due to reduced energy and maintenance expenses. In terms of global warming potential, BEVs show a 4.52% reduction compared to GVs. However, BEVs demonstrate higher impacts in several non-climate categories—including ionizing radiation, particulate matter formation, eutrophication, toxicity, and water use—largely due to emissions from coal-based electricity. The derived grid emission factor of 1.498 kg CO2/kWh underscores the critical role of regional energy structure. These findings suggest that while BEVs provide economic and climate benefits, their overall environmental performance is highly dependent on local grid carbon intensity and seasonal energy demand. Policy recommendations include accelerating grid decarbonization, improving cold weather efficiency, and incorporating multidimensional environmental indicators into transport planning.

A Study on the Application of an Estimated Ammonia Emission Factor Reflecting the Operating Characteristics of Open Laying Hen Houses in Korea

In Korea, winch curtains are used when operating open-type barns. The winch curtain method is a method of opening the curtain by taking into account the temperature, which has the characteristics of an open-type barn when used but can have the discharge characteristics of a closed-type barn when operated in an enclosed manner. In this study, the related methodologies were reviewed and measured to examine and reflect the characteristics of curtain opening in open sheds. The results of NH3 concentration measurements showed that the average daily concentration was 5.60 ppm when operating in an enclosed state, 0.20 ppm when operating in an open state, and 0.70 ppm when operating intermittently. It was found that the operating concentration in a closed state is relatively higher than that in an open and intermittent state. Therefore, it was examined whether the characteristics of open barns differ depending on the type of operation and whether this should be taken into account when developing emission factors. The NH3 emission factor developed in consideration of these characteristics was 0.33 kg NH3/year/animal housing area (AP), which was similar to the emission factor developed overseas.

Reduction of Carbon Footprint in Mechanical Engineering Production Using a Universal Simulation Model

The paper presents the design and development of a universal simulation model named SustainSIM, intended for optimizing the carbon footprint in mechanical engineering production. The objective of this model is to enable enterprises to accurately quantify, monitor, and simulate CO2 emissions generated during various manufacturing processes, thereby identifying and evaluating effective reduction strategies. The paper thoroughly examines methodologies for data collection and processing, determination of emission factors, and categorization of emissions (Scope 1 and Scope 2), utilizing standards such as the GHG Protocol and associated databases. Through a digital simulation environment created in Unity Engine, the model interactively visualizes the impacts of implementing green technologies—such as solar panels, electric vehicles, and heat pumps—on reducing the overall carbon footprint. The practical applicability of the model was validated using a mechanical engineering company as a case study, where simulations confirmed the model’s potential in supporting sustainable decision-making and production process optimization. The findings suggest that the implementation of such a tool can significantly contribute to environmentally responsible management and the reduction of industrial emissions. In comparison to existing methods such as SimaPro/OpenLCA (detailed LCA) and the Corporate Calculator (GHG Protocol), SustainSIM achieves the same accuracy in calculating Scopes 1/2, while reducing the analysis time to less than 15% and decreasing the requirements for expertise. Unlike simulation packages like Energy Plus, users can modify parameters without scripting, and they can see the immediate impact in CO2e.

Evaluating Gas Fuels A DEMATEL-Based Analysis of Emission, Energy, and Economic Factors

The evaluation of gas fuels is a critical process that involves assessing the properties, performance, and environmental impact of different gas fuel sources. Petrol fuels like liquefied petroleum gas and natural gas (LPG), are widely used for various applications, including heating, cooking, and power generation. The evaluation process typically includes analyzing the composition and calorific value of the gas fuels to determine their energy content and efficiency. Additionally, factors such as combustion characteristics, emissions profiles, and safety considerations are taken into account. Evaluating gas fuels also involves assessing their availability, accessibility, and cost-effectiveness. This includes considering factors like production methods, infrastructure requirements, and transportation logistics. Moreover, the environmental impact of gas fuels is a significant aspect of the evaluation process. Evaluators examine the greenhouse gas emissions, air pollutants, and overall sustainability of gas fuels, comparing them to alternative energy sources. This analysis helps inform decision-making regarding the adoption and optimization of gas fuels for a cleaner and more sustainable energy future. The evaluation of gas fuels holds significant research significance due to several key reasons. Firstly, as the world seeks to transition to cleaner and more sustainable energy sources, understanding the properties and environmental impact of gas fuels becomes crucial. This research can inform policymakers, industry professionals, and energy consumers in making informed decisions about energy choices. Secondly, evaluating gas fuels enables the optimization of energy production and consumption processes. By understanding the efficiency and combustion characteristics of different gas fuels, researchers can develop technologies and strategies to enhance energy conversion and reduce emissions. Furthermore, the evaluation of gas fuels plays a vital role in energy security and resource management. Assessing the availability, accessibility, and cost-effectiveness of gas fuels helps identify potential energy reserves, infrastructure requirements, and diversification strategies. Overall, research in evaluating gas fuels contributes to sustainable energy development, climate change mitigation, and the switch to an energy system that is more effective and environmentally benign. “One method employed is the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method to analyze complex systems and relationships among various factors”. It involves constructing a cause-and-effect network, quantifying the relationships between factors, and assessing their impact on decision-making. DEMATEL helps identify influential factors and prioritize actions for effective decision-making. Evaluation Parameters taken as “Low emission (LE), high energy content (HEC), high quality gas (HQG), easy procurement (EP), affordable unit price (AUP Low emission (LE) has got the first rank followed by high energy content (HEC) at the second rank whereas high quality gas (HQG) had got the last rank preceded by easy procurement (EP) at fourth rank. Affordable unit price (AUP) had got third rank. In conclusion, the evaluation of gas fuels plays a crucial role in shaping energy policies, promoting sustainable development, and mitigating environmental impact. By conducting thorough assessments of gas fuel properties, performance, and environmental implications, researchers and decision-makers can make informed choices regarding energy sources. The significance of gas fuel evaluation extends beyond immediate environmental concerns. It also impacts economic factors, such as infrastructure planning, transportation logistics, and energy pricing. By considering the overall sustainability and long-term viability of gas fuels, stakeholders can establish a balanced and resilient energy framework.

A Sustainability-Oriented Framework for Life Cycle Environmental Cost Accounting and Carbon Financial Optimization in Prefabricated Steel Structures

The building sector significantly contributes to global resource depletion and greenhouse gas emissions, necessitating integrated approaches to evaluate both environmental and economic performance. This study developed a sustainability-oriented assessment framework—applied in a Chinese context—that integrates life cycle assessment (LCA), life cycle costing (LCC), and carbon financial optimization to evaluate the life cycle performance of prefabricated steel buildings. Using publicly available databases (CEADs, Ecoinvent, and the Chinese Life Cycle Database), the framework quantified cradle-to-grave environmental impacts across raw material extraction, prefabrication, transport, on-site assembly, operation, and end-of-life stages. Emissions were monetized using standardized emission factors and official cost coefficients, enabling environmental costs to be expressed in financial terms. A dynamic financial simulation module was incorporated to assess the effects of carbon price fluctuations and quota allocation schemes. Sensitivity analyses were performed to examine the influence of key variables such as retrofit investment costs, emission reduction efficiency, and carbon policy scenarios on financial returns. The results show that material production and operational energy use dominate life cycle carbon emissions, jointly contributing more than 90% of the total impacts. Moderate decarbonization investments—such as HVAC upgrades and improved insulation—can achieve positive net economic returns under baseline carbon pricing. This integrated, data-driven framework serves as a practical decision-support tool for policymakers and industry stakeholders. It is adaptable across different regions and material systems, supporting the global transition toward low-carbon and financially viable construction practices.