Journal of the Air & Waste Management Association最新文献

{"title":"Absorption photometry of patterned deposits on IMPROVE PTFE filters.","authors":"Warren H White, Scott A Copeland, Jason Giacomo, Nicole P Hyslop, Lindsay M Kline, William Malm, Sean Raffuse, Bret A Schichtel, Nicholas J Spada, Christopher D Wallis, Xiaolu Zhang","doi":"10.1080/10962247.2024.2442634","DOIUrl":"https://doi.org/10.1080/10962247.2024.2442634","url":null,"abstract":"<p><p>The IMPROVE program (Interagency Monitoring of PROtected Visual Environments) tracks long-term trends in the composition and optics of regional haze aerosols in the United States. The absorptance of red (633-nm) light is monitored by filter photometry of 24 h-integrated samples of fine particulate matter (PM 2.5). These are collected every third day at about 150 rural and often remote locations. Systematic reanalyses of archived samples have established the reproducibility of these optical absorption measurements across decades and instrument systems, with a consistent calibration that is traceable back to 2003.IMPROVE samples for nondestructive analyses by photometry, gravimetry, and X-ray fluorescence are all collected on ring-mounted membranes of expanded PTFE (polytetrafluoroethylene). Although attractively inert, low in blank mass, and optically thin, these media yield visibly nonuniform deposits that do not admit direct interpretation according to a naïve \"Beer-Lambert\" formulation of optical absorption. Most IMPROVE PTFE deposits exhibit a fine-scale \"pixelation\" shaped by the perforated screen that supports the membrane during sample collection.This paper extends the traditional Beer-Lambert interpretive model to accommodate the patterned deposits generated by IMPROVE and similarly aggressive sampling protocols on PTFE filters. The extended model is then used to assess the bias and epistemic uncertainty in the aerosol absorption coefficient that IMPROVE has historically reported.ImplicationsAmbient fine aerosol particles are widely collected at high sample face velocities on PTFE (Teflon®) membrane filters backed by perforated support screens. The screens' localized blockage of airflow can channel the resulting PM2.5 sample deposits into a pattern of discrete heavily loaded \"pixels\", where the screen perforations allow flow through the membrane, separated by a lightly loaded background that reflects blockage by the screen. Such non-uniform deposits, collected throughout the United States on FRM filters to monitor NAAQS compliance and on IMPROVE filters to support the Regional Haze Rule, do not meet the requirements of the Beer-Lambert model for optical absorption measurements. This paper extends Beer-Lambert theory to accommodate patterned deposits, and assesses the bias and epistemic uncertainties introduced by historical (mis)reporting based on \"Beer's Law\". For samples of moderate (and lesser) absorptance, including the bulk of those collected at rural IMPROVE sites to track regional haze, usefully tight bounds are developed for this pixelation bias.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142856390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstruction of a Closed-Loop Ecological Cycle System Anchored by Large-Scale Load-balancing Biogas and its economic viability assessment.","authors":"Jianjun Li, Yiyun Liu, Yuanjie Zhang, Jing Zhu, Rongqi Wu, Shihua Zhang","doi":"10.1080/10962247.2024.2444362","DOIUrl":"https://doi.org/10.1080/10962247.2024.2444362","url":null,"abstract":"<p><p>Biogas can be used for complementary load-balancing with renewable intermittent power, thus maintaining overall energy output stability. However, biogas load balancing load balancing is typically used in small-scale distributed energy systems, constrained by factors such as technology and land requirements, making it challenging to scale up. Therefore, this study proposes a closed-loop ecological cycle system, where biogas provides load leveling support for large-scale intermittent power sources in desertified regions dominated by animal husbandry. The biogas slurry and residue produced are used for land restoration and subsequent cultivation of high-quality economic crops, with the resulting straw used for the next round of biogas production. This study conducts an economic assessment of the aforementioned system and analyzes a case study of a load-balancing biogas project in Northwest China. Accounting results indicating that the system's net present value is 0.108 million yuan/m³, internal rate of return is 0.60%, and payback period is 22 years. Additionally, sensitivity backward deduction analysis identified the reasonable value ranges for key system parameters. According to the results, we offer management recommendations to promote the proposed system, supporting innovative biomass energy utilization and enhancing renewable energy stability.<i>Implications Statement</i>: This research introduces a novel closed-loop ecological cycle system that integrates large-scale peak-shaving biogas with renewable energy sources, offering a sustainable solution for enhancing energy stability and environmental sustainability in desertified areas. The study's economic evaluation reveals the critical role of ecological restoration costs in the overall viability of such systems, indicating the necessity for policy support to make them economically attractive. Our findings suggest that targeted subsidies, based on the quantified ecological benefits, are essential for incentivizing the adoption of this model. By providing specific conditions under which the system is economically feasible, this work informs policymakers on how to design effective incentive structures, thereby promoting the wider application of biogas and contributing to the goals of sustainable development and climate resilience. The research underscores the importance of integrating economic and ecological considerations to achieve long-term sustainability, making it a valuable reference for future energy policies and practices.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142855483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extraction of agricultural plastic greenhouses based on a U-Net convolutional neural network coupled with edge expansion and loss function improvement.","authors":"Weidong Song, Huan He, Jiguang Dai, Guohui Jia","doi":"10.1080/10962247.2024.2412708","DOIUrl":"10.1080/10962247.2024.2412708","url":null,"abstract":"<p><p>Agricultural plastic greenhouses (APGs) are crucial for sustainable agricultural planting, and accurate spatial distribution information acquisition is crucial. Deep learning network models can extract target features from remote sensing images more effectively than traditional interpretation methods, which face challenges like high workloads and poor repeatability. In this study, we aim to enhance the inventorying of Agricultural Plastic Greenhouses (APGs) by improving the extraction accuracy of their locations and numbers through remote sensing techniques. Utilizing GF-7 satellite imagery, we propose an enhanced U-Net convolutional neural network (CNN) model that incorporates edge information expansion and a joint loss function to optimize performance. The primary objective is to provide a rapid and accurate method for mapping APGs, which is crucial for effective agricultural management and environmental monitoring. The U-Net network's accuracy was enhanced by 1.1% after expanding 3 × 3 sample edge information, and further by 1.9% by combining edge extension and loss function constraints. Our results demonstrate that the modified U-Net model significantly improves extraction accuracy compared to traditional methods, thereby facilitating better inventory management and planning for agricultural cash crops. This advancement not only supports farmers in optimizing resources but also contributes to sustainable agricultural practices by enabling precise monitoring of APG distribution.<i>Implications</i>: Compared to traditional interpretation methods, which suffer problems such as heavy workloads, small adaptation ranges and poor repeatability, deep learning network models can better extract target features from remote sensing images. In this study, we used GF-7 image data to improve the traditional U-Net convolutional neural network (CNN) model. The Canny operator and Gaussian kernel (GK) function were used for sample edge expansion, and the binary cross-entropy and GK functions were used to jointly constrain the loss. Finally, APGs were accurately extracted and compared to those obtained with the original model. The results indicated that the APG extraction accuracy of the U-Net network was improved through the expansion of sample edge information and adoption of joint loss function constraints.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":"1-12"},"PeriodicalIF":2.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142511396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The development and application of a new method for quantifying total atmospheric sulfur in the Alberta Oil Sands.","authors":"Cristian Mihele, Jeff Brook, Gang Lu, John Liggio, Ralf M Staebler","doi":"10.1080/10962247.2024.2440034","DOIUrl":"https://doi.org/10.1080/10962247.2024.2440034","url":null,"abstract":"<p><p>Continuous ambient sulfur measurements are routinely conducted around the globe at numerous monitoring sites impacted by industrial sources such as gas and oil processing facilities, pulp and paper mills, smelters, sewage treatment facilities, or concentrated animal feeding operations, as well as natural sources such as volcanoes. Various jurisdictions have or plan to establish Air Ambient Quality Objectives/Guidelines/Standards for Total Reduced Sulfur (TRS) based on odor perception and/or health effects. A conventional TRS monitoring technique is widely used, but few studies have looked at potential biases in the resulting TRS measurements. This paper presents a novel method to quantify Total Sulfur (TS) concentrations to investigate odor events caused by sulfur compounds, and to construct the sulfur budget for sulfur dioxide, particle sulfate, hydrogen sulfide (H₂S) and the sum of all remaining reduced sulfur compounds (non-H₂S RSCs). This methodology was tested and improved through multi-year monitoring (2013-2017) at the Oski-ôtin site in the indigenous community of Fort McKay, in the Alberta Oil Sands Region (AOSR). Comparisons with SO₂ and conventional TRS data from two long-term monitoring sites located within five kilometers of Oski-ôtin suggest that the conventional approach for TRS is biased low by 20% on average. Based on this new method, Sulfur dioxide (SO₂) was observed to be responsible for about 40% of the TS mass in Fort McKay, while TRS and particulate sulfate made up 50% and 10%, respectively. TRS dominated the distribution during winter months when SO₂ plumes emitted from stacks tended to remain elevated due to diminished vertical mixing. During periods with TS below 5 ppb, which was 84% of the time, TRS (with H₂S) accounted for 55% of the sulfur mass observed in Fort McKay.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142808233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of EPA air toxics monitoring data and tools for use in general population exposure assessments: Using acrylonitrile as a case study.","authors":"Amanda Kramer, Stephanie Vivanco, Jennifer Bare, Julie Panko","doi":"10.1080/10962247.2024.2438793","DOIUrl":"https://doi.org/10.1080/10962247.2024.2438793","url":null,"abstract":"<p><strong>Implication statement: </strong>Acrylonitrile was recently proposed to be designated as a high-priority substance for risk evaluation by the U.S. Environmental Protection Agency (EPA) under the Toxic Substances Control Act (TSCA). Past research has characterized the health effects of acrylonitrile and the worker population's exposure to it. However, there has been limited assessment of the general population's exposure to acrylonitrile. The objective of this study was to characterize general population exposure to acrylonitrile via the ambient air and to assess the suitability of EPA monitoring and modeled data for use in regulatory risk assessment. Overall, key findings from this study suggest that general population exposure to acrylonitrile from the ambient air is low and EPA's Air Quality System (AQS) data is well suited for general population exposure evaluations. These results benefit the general public in understanding their potential exposure to acrylonitrile, the EPA in informing their TSCA risk evaluation for acrylonitrile, and other researchers aiming to utilize AQS for general population exposure assessments.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142808229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reaction kinetics and isotherms of commercial activated carbon in variable pressure adsorption of high compound VOCs.","authors":"Chiu-Hsuan Lee, Je-Lueng Shie, Yun-Jie Lu, Min-Hao Yuan, Yi-Hung Chen, Manh Van Do, Ching-Yuan Chang","doi":"10.1080/10962247.2024.2425342","DOIUrl":"10.1080/10962247.2024.2425342","url":null,"abstract":"<p><p>This study investigated the feasibility of using/reusing commercial activated carbon (CAC) for the capture of high molecular weight and high-boiling point volatile organic compounds (HBPVOCs). The CAC was first characterized using proximate analysis, heat value analysis, iodine value analysis, element analysis, inductively coupled plasma spectrometry, and specific surface area analysis. We then assessed the adsorption/desorption performance of a CAC-based PSA system for the removal of Butyl Cellosolve (BCS), a HBPVOC commonly used in paints, coatings, cleaners, and industrial processes. This involved deriving the BCS adsorption capacity of CAC as a function of adsorbent quantity (2.5, 5, and 10 g), flow rate (4, 6, and 8 L/min), and pressure (1.3, 2.3, and 3.4 kg/cm²). The BCS adsorption capacity of the CAC varied with pressure as follows: 1.3 kg/cm² (652.85 mg/g), 2.3 kg/cm² (817.20 mg/g) and 3.4 kg/cm² (1324.05 mg/g). The adsorption mode most closely resembled pseudo-first-order kinetics (i.e. single-layer physical adsorption). Desorption was performed using an adjustable tubular high-temperature furnace under a nitrogen atmosphere (0.93 kg/cm²). Following desorption with a set desorption duration of 1 hr, the BET values varied with temperature as follows: 350°C (75.58% of the original value) and 450°C (86.04% of the original). Desorbed CAC (DCAC) was also examined to detect changes in pore structure due to the effects of recycling. We obtained breakthrough curves and a dsorption capacity curves of CAC as functions of flow rate and pressure. We also investigated adsorption performance under pressure swing conditions from the perspective of reaction kinetics and density functional theory. Our results demonstrate the efficacy of CAC in the adsorption of BCS as well as the recyclability of this material.<i>Implications:</i> This study demonstrates the potential for reusing commercial activated carbon (CAC) to capture high molecular weight and high-boiling point volatile organic compounds (HBPVOCs). Through comprehensive characterization and performance evaluation, we found that CAC effectively adsorbs Butyl Cellosolve (BCS), a common industrial solvent, with adsorption capacity increasing with pressure. The adsorption process follows pseudo-first-order kinetics, indicating single-layer physical adsorption. Additionally, the study highlights the recyclability of CAC, as desorption and subsequent analysis revealed minimal changes in pore structure, maintaining a significant portion of its original BET value. These findings suggest that CAC is not only effective for BCS adsorption but also sustainable for repeated use, offering an efficient and eco-friendly solution for managing industrial HBPVOCs.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142631230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating methane emissions from the waste sector in southern ontario using atmospheric measurements.","authors":"Lawson David Gillespie, Sébastien Ars, Samantha Alkadri, Siyar Urya, Timothy Khoo, Susan Fraser, Felix Vogel, Debra Wunch","doi":"10.1080/10962247.2024.2435340","DOIUrl":"https://doi.org/10.1080/10962247.2024.2435340","url":null,"abstract":"<p><p>We estimate methane emissions rates for urban waste treatment facilities from mobile in situ atmospheric concentration measurements using an inverse Gaussian plume methodology at facilities in Southern Ontario, Canada. We use these estimated emissions rates to investigate, update, and improve the existing high resolution methane inventories at the facility level for waste sources throughout the Greater Toronto Area and Southwestern Ontario. Our measurements encompass tens of thousands of kilometers worth of mobile survey data collected over 7 years, encompassing more than 650 downwind transects where we surveyed 14 active landfills, 11 closed landfills, 2 organic waste processing facilities, 3 open air windrow compost facilities, and 11 water resource recovery facilities across our study region. These sources account for 77% of the active landfills within Southern Ontario, which is estimated in inventories to be the largest source of methane emissions in the region. Within the Greater Toronto Area (GTA) megacity, the measured facilities represent about 52% of the total inventoried non-wetland methane emissions. We find that emissions from closed landfills are lower than inventory estimates, with significant implications for the methane budget in the GTA. We update the Facility Level and Area Methane Emissions for the GTA inventory with our measured emissions rates, which results in a 54% decline in the solid waste emissions, effecting a 35% lower estimate for the total anthropogenic methane emissions in the region. We attribute the bulk of this difference to a single facility: the Keele Valley landfill. Our atmospheric measurements also serve as a novel metric for evaluating the discrepancies between four facility level, and two high resolution gridded methane emissions inventories. Based on linear regressions of our measured emissions versus inventoried values, we find that the facility level first order decay model maintained by Environment and Climate Change Canada (ECCC) to be the most consistent with our measured emissions rates at landfills and the self-reported emissions to the Greenhouse Gas Reporting Program of ECCC to be the least consistent with our measurements.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142773994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Municipal solid waste management in Ethiopia - Physical and chemical compositions and generation rate: Systematic review.","authors":"Tsegay Kahsay Gebrekidan, Gebremariam Gebrezgabher Gebremedhin, Abraha Kahsay Weldemariam, Meaza Kidane Teferi","doi":"10.1080/10962247.2024.2416588","DOIUrl":"10.1080/10962247.2024.2416588","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Municipal solid waste management (MSWM) in Ethiopia is a complex issue with institutional, social, political, environmental, and economic dimensions, impacting sustainable development. Effective MSWM planning necessitates understanding the generation rate and composition of waste. This systematic review synthesizes qualitative and quantitative data from various sources to aggregate current knowledge, identify gaps, and provide a comprehensive understanding of municipal solid waste management in Ethiopia. The findings reveal that the generation rate of municipal solid waste in Ethiopia is 0.38 kg/ca/day, with the waste composition being predominantly food waste, followed by ash, dust, and sand, and yard waste. Over 85% of this MSW is either reusable or recyclable, with a significant portion being organic matter (73.13% biodegradable) and 11.78% recyclable materials. Physicochemical analyses reveal that Ethiopian MSW is suitable for composting and biogas production, offering opportunities to reduce environmental pollution, and GHGs, support urban agriculture, and create job opportunities. However; challenges persist, including a lack of political will, weak municipal planning, limited community awareness, and inadequate waste management infrastructure, and only 31.8% of MSW is collected legally, leading to inefficient and harmful disposal practices. To improve MSWM, Ethiopia should focus on public awareness; increased funding, infrastructure investment, private sector partnerships, and implementing the 4 R principles (reduce, reuse, and recycle). An integrated approach involving government, industry, and civil society is essential. Further research on the physicochemical properties and strategic uses of MSW is needed to enhance management practices.&lt;i&gt;Implications:&lt;/i&gt; The comprehensive study of municipal solid waste management (MSWM) in Ethiopia reveals the intricate interplay of institutional, social, political, environmental, and economic factors that influence the nation's sustainable development. The findings underscore the urgent need for tailored, integrated waste management strategies that are informed by a thorough understanding of MSW generation rates, composition, and current management practices. Ethiopia's lower per capita MSW generation compared to developed countries and the predominantly organic composition of its waste present significant opportunities for sustainable waste management practices such as composting and recycling. These practices can not only minimize the environmental impact but also support urban greening, agriculture, and renewable energy production. The high organic content, suitable physicochemical properties of MSW for composting, and potential for biogas and briquette production highlight pathways for creating employment, reducing waste, and enhancing soil fertility. Despite these opportunities, Ethiopia faces substantial challenges due to inadequate political will, weak municipal planning, limited commun","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":"861-883"},"PeriodicalIF":2.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142511398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation on exhaled aerosol transmission based on realistic oral-nasal structures and temperature distribution.","authors":"Chong Zhu, Hao Xie, Xiaole Chen, Xinye Wang, Junguang Meng, Jiayu Wei, Zhonghui Zhao","doi":"10.1080/10962247.2024.2416927","DOIUrl":"10.1080/10962247.2024.2416927","url":null,"abstract":"<p><p>Respiratory infections are currently understood to be caused by pathogens released through the nose or mouth of an infected individual, and subsequently transmitted to susceptible hosts. These pathogens are enclosed in liquid particles that are aerosolized from the respiratory tract during activities such as breathing, speaking, sneezing, and coughing. These particles vary widely in size, ranging from submicron to several microns. While past research has largely overlooked the human respiratory system, recent analysis has revealed that the actual structure of the nasal cavity significantly influences the prediction of aerosol transmission during exhalation. In this study, computational fluid dynamics (CFD) simulations were conducted to analyze the aerosol transmission generated during exhalation from the nasal and oral cavities. Realistic nasal and oral cavity structures were taken into account, and authentic temperature distributions were applied to the surfaces. Additionally, inhalation conditions for susceptible individuals were established to evaluate the risk of inhalation-generated exposure. Through various simulation scenarios, we separately discussed the impact of environmental wind speed, separation distance, and exhalation flow rate. The simulation results indicate that environmental wind amplifies the complexity of the flow field and the transmission and deposition of particles between two individuals. Under ambient wind velocities of 0.5 m/s and 1 m/s, it was observed that over 80% of the particles with a diameter of 1 µm inhaled through the nasal cavity accounted for the total deposition on the infected individual. Furthermore, high exhalation flow rates exhibited higher deposition ratios at close distances, in line with our expectations. Therefore, it is advisable to minimize close contact as much as possible during periods of frequent respiratory infections, and to wear masks in order to reduce the risk of inhalation exposure.<i>Implications</i>: During the activities such as breathing, speaking, sneezing, and coughing, liquid particles containing pathogens are aerosolized from the respiratory tract and are released from nose or mouth through the nebulization. In this study, we investigated the transmission of aerosols from human exhalation in the outdoor environment, innovatively taking the real oral-nasal structure and the active inhalation of vulnerable people into consideration, and explored the human-to-human transmission of respiratory viruses. The results are beneficial for public health assessment and policy development.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":"905-919"},"PeriodicalIF":2.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142478753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevated airborne radioactivity downwind of a Colorado oil refinery.","authors":"Detlev Helmig, Justin Nobel, Dani Caputi, David Brown, Ryan W Daly, Lisa S Darby, Phillip T Doe, Olga Gonzalez, Gabriel Greenberg, Jacques Hueber, Kat Potter, Gunnar W Schade, Susan Simoncic, Michel Stahli, Wilma Subra","doi":"10.1080/10962247.2024.2393194","DOIUrl":"10.1080/10962247.2024.2393194","url":null,"abstract":"<p><p>Airborne radioactivity from fossil fuel production systems is poorly characterized, but a recent study showed elevated ambient levels with proximity to oil and gas production wells. Here, we report year-long, high temporal resolution monitoring results of airborne alpha radioactivity from both radon gas and radon progeny attached to particulates immediately northeast of an oil refinery in Commerce City, Colorado, USA, in an environmental justice community of concern. Gas and particle-associated radioactivity contributed nearly evenly to the total alpha radioactivity. Total radioactivity levels of 30-40 Bq m^-3 were 2-3 times higher than background levels (~10-15 Bq m^-3) when winds were light and southwesterly, suggesting the refinery as the geographic origin. Furthermore, elevated airborne radioactivity tracked most closely with the light hydrocarbon and natural gas tracer ethane. Thus, the data imply natural gas as the radon emission carrier. Our findings are unique and suggest a need for further investigations of radon emissions from oil and gas infrastructure such as natural gas processing plants, compressor stations, petrochemical plants, and oil refineries that process oil and natural gas from unconventional production.<i>Implications</i>: Regulatory agencies currently do not mandate or conduct monitoring of radioactivity releases and public exposure from petroleum industry air emissions. This study reports elevated radioactivity from radon gas and nonvolatile radon decay products attached to particulate matter, at about 2-3 times above background levels in proximity to Colorado's largest oil refinery. Observations were within an environmental justice community of concern that experiences well above-average exposure to many other harmful atmospheric pollutants, suggesting potential adverse health effects from this cumulative exposure. Our findings offer actionable insights for policymakers, industry stakeholders, and affected communities alike.</p>","PeriodicalId":49171,"journal":{"name":"Journal of the Air & Waste Management Association","volume":" ","pages":"920-931"},"PeriodicalIF":2.1,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142074342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}