Air Quality Degradation Research Articles

IoT Based Automatic Air Pollution Monitoring and Purification System

Abstract: Degradation of air quality, like climate change and global warming, has become an all-encompassing existential hazard to humanity and natural life. Exposure to severely polluted air on a regular basis causes pulmonary disorders and contributes to severe allergies and asthma. According to studies, more than 10 million people die each year as a result of irregularities produced directly or indirectly by air pollution. The work of Lelieveld et al. [1] sheds light on the gravity of the problem. It is estimated that by 2050, the worldwide premature mortality from air pollution will exceed 6.6 million fatalities per year (358000 from ozone, the rest from PM 2.5) [1]. As a result, we decided to focus our study on improving indoor air quality. Despite the fact that there are numerous indoor air purifiers on the market, their cost belies their effectiveness, and the effective ones are far too expensive for working-class people to afford [2]. In order to address this issue, we created an automated Internet of Things (IoT) based air filtration system that uses an automated air purifier which is triggered when air quality falls below WHO criteria. Our initiative intends to improve indoor air quality by utilizing the most cost-effective and efficient modules available. Keywords: Indoor Air Pollution, Air Purifier, IAQ, Sharp Dust Sensor GP2Y1010AU0F, IoT, Particulate Matter (PM), HEPA Filter

Particle release from refit operations in shipyards: Exposure, toxicity and environmental implications

European harbours are known to contribute to air quality degradation. While most of the literature focuses on emissions from stacks or logistics operations, ship refit and repair activities are also relevant aerosol sources in EU harbour areas. Main activities include abrasive removal of filler and spray painting with antifouling coatings/primers/topcoats. This work aimed to assess ultrafine particle (UFP) emissions from ship maintenance activities and their links with exposure, toxicity and health risks for humans and the aquatic environment. Aerosol emissions were monitored during mechanical abrasion of surface coatings under real-world operating conditions in two scenarios in the Mallorca harbour (Spain). Different types of UFPs were observed: (1) highly regular (triangular, hexagonal) engineered nanoparticles (Ti-, Zr-, Fe-based), embedded as nano-additives in the coatings, and (2) irregular, incidental particles emitted directly or formed during abrasion. Particle number concentrations monitored were in the range of industrial activities such as drilling or welding (up to 5 ∗ 105/cm3, mean diameters <30 nm). The chemical composition of PM4 aerosols was dominated by metallic tracers in the coatings (Ti, Al, Ba, Zn). In vitro toxicity of PM2 aerosols evidenced reduced cell viability and a moderate potential for cytotoxic effects. While best practices (exhaust ventilation, personal protective equipment, dust removal) were in place, it is unlikely that exposures and environmental release can be fully avoided at all times. Thus, it is advisable that health and safety protocols should be comprehensive to minimise exposures in all types of locations (near- and far-field) and periods (activity and non-activity). Potential release to coastal surface waters of metallic engineered and incidental nanomaterials, as well as fine and coarse particles (in the case of settled dust), should be assessed and avoided.

Relating air quality and other factors to comfort and health related symptoms reported by passengers and crew on commercial transport aircraft (ASHRAE RP-1262)

Passenger and flight crew concerns over the negative impact of the aircraft cabin environment on health and comfort have lingered for years. During flight, passengers and crew can experience reduced atmospheric pressure, low relative humidity, and potential air quality degradation, which could lead to adverse health complaints. The goal of this project was to investigate the potential link between perceived health symptoms and discomfort and aircraft cabin environmental conditions and human factors. Passengers and crew completed validated health and comfort surveys on 130 domestic and international flights across varied aircraft, durations, and seasons. Environmental conditions and airborne levels of contaminants were measured during 80 of these flights. Extremes in cabin temperature or degraded air quality parameters led to higher rates of passenger discomfort. Odds ratios were higher for several adverse health symptoms for certain aircraft types and durations, while ventilation rates were positively correlated with discomfort and adverse health symptoms. Median levels of CO, CO2, and ozone were below established exposure limits. Results from this study help further our knowledge of aircraft comfort and can help airlines and industry agencies determine the most critical impacts on health and comfort to better inform standards to improve passenger and crew experiences.

Air Pollution From Forest and Vegetation Fires in Southeast Asia Disproportionately Impacts the Poor.

Forest and vegetation fires, used as tools for agriculture and deforestation, are a major source of air pollutants and can cause serious air quality issues in many parts of Asia. Actions to reduce fire may offer considerable, yet largely unrecognized, options for rapid improvements in air quality. In this study, we used a combination of regional and global air quality models and observations to examine the impact of forest and vegetation fires on air quality degradation and public health in Southeast Asia (including Mainland Southeast Asia and south‐eastern China). We found that eliminating fire could substantially improve regional air quality across Southeast Asia by reducing the population exposure to fine particulate matter (PM2.5) concentrations by 7% and surface ozone concentrations by 5%. These reductions in PM2.5 exposures would yield a considerable public health benefit across the region; averting 59,000 (95% uncertainty interval (95UI): 55,200–62,900) premature deaths annually. Analysis of subnational infant mortality rate data and PM2.5 exposure suggested that PM2.5 from fires disproportionately impacts poorer populations across Southeast Asia. We identified two key regions in northern Laos and western Myanmar where particularly high levels of poverty coincide with exposure to relatively high levels of PM2.5 from fires. Our results show that reducing forest and vegetation fires should be a public health priority for the Southeast Asia region.

Evaluation of Antimicrobial Effect of Zinc Pyrithione against Airborne Fungi and Bacteria Growth Collected onto New and Loaded HVAC Fibrous Filters

Microbial growth onto HVAC filters was observed in real conditions with possible degradation of the indoor air quality. The filtration performance of marketed antimicrobial filters containing zinc pyrithione was tested under laboratory conditions and compared to that of similar filters with the same classification, F7 (EN779:2002). The filtration performance of the two tested filters during loading with PM10 particles was quantified in an experimental setup with filter pressure drop measurement and particle counting upstream and downstream of the filters. The microbial growth on the new and loaded filters, both contaminated with a microbial airborne consortium composed of two bacteria (Gram-positive and -negative) and fungi, was quantified by colony-forming units after conditioning the filters for a few days under controlled temperature (25 °C) and humidity (50% or 90% relative humidity). The results reveal that there was no degradation of the filtration performance of the filters treated with the antimicrobial agent. The efficiency of the antimicrobial treatment, i.e., the ability to inhibit the growth of microorganisms during the incubation period, was significant with the new filters regarding the fungal growth, but the results demonstrate that the antimicrobial treatment became inefficient with the loaded filters.

Quantifying the impact of cropland wind erosion on air quality: A high-resolution modeling case study of an Arizona dust storm

Dust storms fueled by wind erosion of desert and cropland soils in south-central Arizona have caused numerous highway accidents and health risks by creating hazardous air quality conditions. Despite much speculation that a major fraction of windblown dust during these storms originates at an active or abandoned cropland surface over the region, its quantification is largely missing in the literature. This study estimated the contribution of cropland wind erosion to the regional air quality degradation, in terms of concentration of particulate matter with diameter 10 μm and smaller (PM10), during a typical springtime dust storm, by conducting high-resolution (1 km horizontally) simulations utilizing the Weather Research and Forecasting-FENGSHA (a dust emission model)-Community Multiscale Air Quality (WRF-FENGSHA-CMAQ) modeling framework. The dust model for this study employed up-to-date and very high-resolution data on land use, soil texture, and vegetation index. The modeling system used in this study simulated reasonably well a regional dust storm (that raised concerns for air quality and highway safety) of 08–09 April 2013 compared against ground (station) observations of PM10 and satellite observations of dust optical depth and vertical structure of aerosol subtypes. The model evaluations also included the use of radar observations.Furthermore, the model results from this study revealed that the cropland wind erosion was responsible for 55% and 51% of total PM10 over Phoenix (33.35°N–33.85°N, 112.36°W–111.485°W) and western Pinal County (32.50°N–33.35°N, 112.2°W–111.2°W), respectively, during the simulated dust storm. The large contributions suggest that the inclusion and accurate representation of cropland dust sources are crucial in preparing emission inventories and in air quality modeling for the region. Such representation is particularly important in view of the projected future aridity over this region (that is already under a long-term drought), which may lead to fallowing of currently active farmlands, making them potential hotspots of dust emission. The modeling approach developed for this work can be used to carry out more comprehensive studies, over extended spatial and temporal extents, to identify the sources of windblown dust and quantify their climatological dust emission potentials for this region or elsewhere. Such studies are highly desirable to help decision-making processes to reduce windblown dust and the associated health and safety risks.

ADABBOY: African Dust And Biomass Burning Over Yucatan

AbstractBiomass burning (BB) emissions and African dust (AD) are often associated with poor regional air quality, particularly in the tropics. The Yucatan Peninsula is a fairly pristine site due to predominant trade winds, but occasionally BB and AD plumes severely degrade its air quality. The African Dust And Biomass Burning Over Yucatan (ADABBOY) project (January 2017–August 2018) was conducted in the Yucatan Peninsula to characterize physical and biological properties of particulate pollution at remote seaside and urban sites. The 18-month-long project quantified the large interannual variability in frequency and spatial extent of BB and AD plumes. Remote and urban sites experienced air quality degradation under the influence of these plumes, with up to 200% and 300% increases in coarse particle mass under BB and AD influence, respectively. ADABBOY is the first project to systematically characterize elemental composition of airborne particles as a function of these sources and identify bioaerosol over Yucatan. Bacteria, actinobacteria (both continental and marine), and fungi propagules vary seasonally and interannually and revealed the presence of very different species and genera associated with different sources. A novel contribution of ADABBOY was the determination of the ice-nucleating abilities of particles emitted by different sources within an undersampled region of the world. BB particles were found to be inefficient ice-nucleating particles at temperatures warmer than −20°C, whereas both AD and background marine aerosol activated ice-nucleating particles below −10°C.

Global air quality and health impacts of domestic and international shipping

Shipping activities contribute to degraded air quality and premature mortalities worldwide, but previous assessments of their health impact have not yet differentiated contributions from domestic and international shipping at the global level. The impacts of domestic shipping can affect different populations, and domestic and international shipping emissions are governed under different regulatory systems. Thus, a consistent global analysis comparing the health impacts from domestic and international shipping could inform policy making in attempts to coordinate policies across multiple scales to address the health burden of shipping emissions. In this study, we create bottom-up global ship emission inventories based on ship activity records from the automatic identification system, and then apply the GEOS-Chem atmospheric model and global exposure mortality model to quanitfy shipping-related PM2.5-concentrations and associated mortalities. We also quantify the public health benefits under different control scenarios including the 2020 0.5% sulphur cap, a post-2020 0.1% sulphur cap, and a post-2020 Tier III NO x standard. We find that 94 200 (95% confidence interval: 84 800–103 000) premature deaths were associated with PM2.5 exposure due to maritime shipping in 2015, of which 83% were associated with international shipping activities and 17% with domestic shipping. Although the global health burdens of ship emissions are dominated by international shipping, the fraction varies by region: 44% of shipping-related premature deaths in China come from domestic shipping activities. We estimate about 30 200 (27 200–33 000) avoided premature deaths per year under a scenario consistent with a 2020 0.5% sulphur cap. We find that a post-2020 Tier III NO x standard would have greater benefits than a post-2020 0.1% sulphur cap, with the two policies reducing annual shipping-attributable PM2.5-related premature deaths by 33 300 (30 100–36 400) and 5070 (4560–5540), respectively.

How It Works: An electric fix for aviation's air pollution problem [design &amp; production - aircraft

Land vehicles&apos; contribution to degrading air quality and climate change is significant. However, a study led by a team at Massachusetts Institute of Technology (MIT) has found that aviation emissions are an increasingly important contributor to anthropogenic climate change. Upon reaching cruise altitude, aeroplanes spew out steady streams of oxides into the atmosphere. The suspended oxides, mostly nitrogen, linger long enough to spark new chemical reactions with atmospheric oxygen, producing ozone and fine particulate matter. Such highly reactive and toxic nitrogen oxides (NOx) are known to cause asthma, decreased lung function and cardiovascular disorders. Fortunately, there now seems to be a fix. With a new concept for aircraft propulsion, MIT engineers claim they can finally solve aviation&apos;s air pollution problem. The prototype aeroplane, which they say is capable of cutting aviation&apos;s hazardous nitrogen oxide emissions by 95 per cent, takes its inspiration from heavy-duty ground vehicles with post-combustion emission control systems.

Investigating Carbonaceous Aerosol and Its Absorption Properties From Fires in the Western United States (WE‐CAN) and Southern Africa (ORACLES and CLARIFY)

AbstractBiomass burning (BB) produces large quantities of carbonaceous aerosol (black carbon and organic aerosol, BC and OA, respectively), which significantly degrade air quality and impact climate. BC absorbs radiation, warming the atmosphere, while OA typically scatters radiation, leading to cooling. However, some OA, termed brown carbon (BrC), also absorbs visible and near UV radiation; although, its properties are not well constrained. We explore three aircraft campaigns from important BB regions with different dominant fuel and fire types (Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen [WE‐CAN] in the western United States and ObseRvations of Aerosols above CLouds and their intEractionS and Cloud‐Aerosol‐Radiation Interactions and Forcing for Year downwind of southern Africa) and compare them with simulations from the global chemical transport model, GEOS‐Chem using GFED4s. The model generally captures the observed vertical profiles of carbonaceous BB aerosol concentrations; however, we find that BB BC emissions are underestimated in southern Africa. Our comparisons suggest that BC and/or BrC absorption is substantially higher downwind of Africa than in the western United States and, while the Saleh et al. (2014, https://doi.org/10.1038/ngeo2220) and FIREX parameterizations based on the BC:OA ratio improve model‐observation agreement in some regions, they do not sufficiently differentiate absorption characteristics at short wavelengths. We find that photochemical whitening substantially decreases the burden and direct radiative effect of BrC (annual mean of +0.29 W m−2 without whitening and +0.08 W m−2 with). Our comparisons suggest that whitening is required to explain WE‐CAN observations; however, the importance of whitening for African fires cannot be confirmed. Qualitative comparisons with the OMI UV aerosol index suggest our standard BrC whitening scheme may be too fast over Africa.

High-frequency assessment of air and water quality at a concentration animal feeding operation during wastewater application to spray fields

Air and water quality at a concentrated animal feeding operation (CAFO) in Eastern North Carolina that uses a covered lagoon and anaerobic digester was evaluated for 2 weeks in August 2020. Real-time PM2.5 mass concentrations were determined using a reference ADR-1500 nephelometer and high-frequency measurements of dissolved inorganic nitrogen (DIN) were evaluated using autonomously logging sensors. Air and water quality parameters were assessed before, during and after wastewater from the lagoon was irrigated onto adjacent spray fields. Reference measurements were conducted alongside a HOBO weather station to collect real-time wind speed and direction, temperature, and humidity measurements. PM2.5 concentrations varied between 0 and 159 μg/m3 with an average concentration of 11 μg/m3, below EPA standard for secondary aerosols of 15 μg/m3. Higher PM2.5 concentrations were observed when wind originated from swine barns but not from covered lagoons. Water quality data showed that DIN concentrations downgradient from the CAFO were elevated relative to upstream concentrations. A groundwater seep that drains a spray field contained the highest average DIN concentration (31.0 ± 12.8 mg L−1), which was 25 times greater than upstream DIN concentrations (1.2 ± 0.8 mg L−1). Average DIN concentration at the downstream station was lower than the seep concentration (8.6 ± 16.2 mg L−1), but approximately 8 times greater than upstream. Air quality data show that the lagoon cover was effective at mitigating air quality degradation, whereas DIN concentrations in water were similar to previous studies on CAFOs using open lagoons. In addition, air and water quality parameters were significantly (p < 0.001) higher after irrigation, indicating possible influence due to ammonia and nitrate elevation. Additional research is needed to compare high-frequency data collected from swine CAFOs using capped and uncapped lagoon systems to better understand spatiotemporal air and water quality trends of this practice.

SAT-CEP-monitor: An air quality monitoring software architecture combining complex event processing with satellite remote sensing

Air pollution is a major problem today that causes serious damage to human health. Urban areas are the most affected by the degradation of air quality caused by anthropogenic gas emissions. Although there are multiple proposals for air quality monitoring, in most cases, two limitations are imposed: the impossibility of processing data in Near Real-Time (NRT) for remote sensing approaches and the impossibility of reaching areas of limited accessibility or low network coverage for ground data approaches. We propose a software architecture that efficiently combines complex event processing with remote sensing data from various satellite sensors to monitor air quality in NRT, giving support to decision-makers. We illustrate the proposed solution by calculating the air quality levels for several areas of Morocco and Spain, extracting and processing satellite information in NRT. This study also validates the air quality measured by ground stations and satellite sensor data.

A Record-Breaking Trans-Atlantic African Dust Plume Associated with Atmospheric Circulation Extremes in June 2020

AbstractHigh concentrations of dust can affect climate and human health, yet our understanding of extreme dust events is still limited. A record-breaking trans-Atlantic African dust plume occurred during 14–28 June 2020, greatly degrading air quality over large areas of the Caribbean Basin and the United States. Daily PM2.5 concentrations exceeded 50 µg m−3 in several Gulf States, while the air quality index reached unhealthy levels for sensitive groups in more than 11 states. The magnitude and duration of aerosol optical depth over the tropical North Atlantic Ocean were the greatest ever observed during summer over the past 18 years based on satellite retrievals. This extreme trans-Atlantic dust event is associated with both enhanced dust emissions over western North Africa and atmospheric circulation extremes that favor long-range dust transport. An exceptionally strong African easterly jet and associated wave activities export African dust across the Atlantic toward the Caribbean in the middle to lower troposphere, while a westward extension of the North Atlantic subtropical high and a greatly intensified Caribbean low-level jet further transport the descended, shallower dust plume from the Caribbean Basin into the United States. Over western North Africa, increased dust emissions are associated with strongly enhanced surface winds over dust source regions and reduced vegetation coverage in the western Sahel. While there are large uncertainties associated with assessing future trends in African dust emissions, model-projected atmospheric circulation changes in a warmer future generally favor increased long-range transport of African dust to the Caribbean Basin and the United States.

Developing an ANN-based early warning model for airborne particulate matters in river banks areas

The adverse effects of dust storms such as air quality degradation, reduced visibility and property damage are particularly prominent in estuarian regions. To reduce significant property and health risks posed by such river dust storms, an early-warning system is a useful tool that is urgently needed. In this case study of an area near an estuary, an artificial neural network with various sampling strategies is proposed for building an early-warning model. Records of past river episodes involving high concentrations of airborne particulate matter were collected and used for modeling. Among the three models developed, Model III which considers the characteristics of both environmental media and pollution sources was most accurate among other Models in predicting the severity of an estuarian dust events. The results revealed that the proposed forecasting model can efficiently predict high-pollution events and thus provide useful information enabling administrators and the public to implement preemptive disaster mitigative measures to avoid the negative health consequences of dust storms within estuarian regions.

The removal of PM2.5 by trees in tropical Andean metropolitan areas: an assessment of environmental change scenarios.

Metropolitan areas in Andean industrialized valleys with a strong geomorphological structure and a pronounced climate experience an increasing degradation of air quality, which motivates environmental policies that include the expansion of tree coverage in urban areas among the mitigation measures. Using the metropolitan area of the Aburrá Valley, Colombia, as a study case, we evaluate the removal of PM2.5 by urban trees with the Urban Forest Effects (UFORE) methodology, considering the potential effect of changing tree covers in the valley for several projected meteorological conditions under climate change and different urban management practices. The estimated removals are sensitive to the number and distribution of available ground stations, with a tendency to overestimate with fewer stations. We found that the marginal gains in removal by additional tree plantings are low in the urbanized settings. In the environmental scenarios, the main limiting factor in the removal is precipitation, compared to changes in tree cover and levels of pollution. Spatially, the increase in total removal depends on the increase in tree cover, with more benefits obtained when trees are in areas with high concentrations of PM2.5. Trees with low values of leaf area index (LAI) seem to optimize the effectiveness of the removal. Seasonally, the greatest removal occurs in rainy months when pollution levels are the highest. Based on our results, the scenarios that meet the plans and programs aimed at improving air quality would achieve removal effectiveness of around 2.5% of the total emissions of PM2.5 with urban trees. Air quality would achieve removal effectiveness of around 2.5% of the total emissions of PM2.5 with urban trees.

Sustaining Rice Production through Biofertilization with N2-Fixing Cyanobacteria

Current agricultural productivity depends on an exogenous nutrient supply to crops. This is of special relevance in cereal production, a fundamental part of the trophic chain that plays a vital role in the human diet. However, our agricultural practices entail highly detrimental side-effects from an environmental point of view. Long-term nitrogen fertilization in croplands results in degradation of soil, water, and air quality, producing eutrophication and subsequently contributing to global warming. In accordance with this, there is a biotechnological interest in using nitrogen-fixing microorganisms to enhance crop growth without adding chemically synthesized nitrogen fertilizers. This is particularly beneficial in paddy fields, where about 60% of the synthetic fertilizer that has been applied is dissolved in the water and washed away. In these agricultural systems, N2-fixing cyanobacteria show a promising biotechnological potential as biofertilizers, improving soil fertility while reducing the environmental impact of the agricultural practice. In the current study, Andalusian paddy fields have been explored to isolate N2-fixing cyanobacteria. These endogenous microorganisms have been subsequently re-introduced in a field trial in order to enhance rice production. Our results provide valuable insights regarding the use of an alternative natural source of nitrogen for rice production.

Local synergies and antagonisms between meteorological factors and air pollution: A 15-year comprehensive study in the Sydney region

Associated with rapid urbanization and escalation of bushfire events, Sydney has experienced significant air quality degradation in the XXI century. In this study, we present a 15-year retrospective analysis on the influence of individual meteorological factors on major air pollutants (NO2, O3, PM10 and PM2.5) at 14 different sites in Greater Sydney and Illawarra. By applying a newly developed “zooming in” approach to long-term ground-based data, we disclose general, seasonal, daily and hourly patterns while increasing the level of spatial associativity. We provide evidence on the pivotal role played by urbanization, sprawling dynamics, global warming and bushfires on local meteorology and air pollution. We strike associations between temperature and O3, both as average trends and extremes, on account of increasing heat island effects. The role of wind in a coastal-basin environment, influenced by a vast desert biome inland, is investigated. A steady trend towards stagnation is outlined, boosted by enhanced urban roughness and intensified heat island circulation. Relative humidity is also crucial in the modulation between NO2 and O3. With a sharp tendency towards drier and hotter microclimates, NO2 levels dropped by approximately 50% over the years at all locations, while O3's median levels almost doubled in the last 10 years. Further, O3 and PMs shifted towards more frequent extreme events, strongly associated with the exacerbation of bushfire events. Such results suggest an urgent need to prioritize emission control, building air tightness improvement and urban heat mitigation, towards a future-proof governance in Sydney and similar regions in the world.

Source apportionment of SPM by positive matrix factorization and PM2.5 analysis in an urban industrial area

PurposeThe purpose of this study is to monitor suspended particulate matter (SPM), PM2.5 and source apportionment study for the identification of possible sources during the year 2018–2019 at Raipur, India.Design/methodology/approachSource apportionment study was performed using a multivariate receptor model, positive matrix factorization (PMFv5.0) with a view to identify the various possible sources of particulate matter in the area. Back-trajectory analysis was also performed using NOAA-HYSPLIT model to understand the origin and trans-boundary movement of air mass over the sampling location.FindingsDaily average SPM and PM2.5 aerosols mass concentration was found to be 377.19 ± 157.24 µg/m³ and 126.39 ± 37.77 µg/m³ respectively. SPM and PM2.5 mass concentrations showed distinct seasonal cycle; SPM – (Winter ; 377.19 ±157.25 µg/m?) > (Summer; 283.57 ±93.18 µg/m?) > (Monsoon; 33.20 ±16.32 µg/m?) and PM2.5 – (Winter; 126.39±37.77 µg/m³) > (Summer; 75.92±12.28 µg/m³). Source apportionment model (PMF) have been applied and identified five major sources contributing the pollution; steel production and industry (68%), vehicular and re-suspended road dust (10.1%), heavy oil combustion (10.1%), tire wear and brake wear/abrasion (8%) and crustal/Earth crust (3.7%). Industrial activities have been identified as major contributing factor for air quality degradation in the region.Practical implicationsChemical characterization of aerosols and identification of possible sources will be helpful in abatement of pollution and framing mitigating strategies. It will also help in standardization of global climate model.Originality/valueThe findings provide valuable results to be considered for controlling air pollution in the region.

Tracking Smoke from a Prescribed Fire and Its Impacts on Local Air Quality Using Temporally Resolved GOES-16 ABI Aerosol Optical Depth (AOD)

AbstractAerosol optical depth (AOD) retrieved from the GOES-16 Advanced Baseline Imager (ABI) was used to track a smoke plume from a prescribed fire in northeastern Virginia on 8 March 2020. Weather and atmospheric conditions created a favorable environment to transport the plume through the Washington, D.C., and Baltimore, Maryland, metro areas in the afternoon and concentrate smoke near the surface, degrading air quality for several hours. ABI AOD with 5-min temporal resolution and 2-km spatial resolution definitively identified the timing and geographic extent of the plume during daylight hours. Comparison to AERONET AOD indicates that ABI AOD captured the relative change in AOD due to passage of the smoke, with a mean absolute error of 0.047. Ground-based measurements of fine particulate matter (PM2.5) confirm deteriorations in air quality coincident with the progression of the smoke. Ceilometer aerosol backscatter profiles verify plume transport timing and indicate that smoke aerosols were well mixed in a shallow boundary layer. This event illustrates the advantages of using multiple datasets to analyze the impacts of aerosols on ambient air quality. Given the quickly evolving nature of the event over several hours, ABI AOD provided information for the public and decision-makers that was not available from any other source, including polar-orbiting satellite sensors. This study suggests that PM2.5 concentrations estimated from ABI AOD can be used to fill in the gaps in nationwide regulatory PM2.5 monitor networks and may be a valuable addition to EPA’s PM2.5 NowCast of current air quality conditions.

Measurement report: Firework impacts on air quality in Metro Manila, Philippines, during the 2019 New Year revelry

Abstract. Fireworks degrade air quality, reduce visibility, alter atmospheric chemistry, and cause short-term adverse health effects. However, there have not been any comprehensive physicochemical and optical measurements of fireworks and their associated impacts in a Southeast Asia megacity, where fireworks are a regular part of the culture. Size-resolved particulate matter (PM) measurements were made before, during, and after New Year 2019 at the Manila Observatory in Quezon City, Philippines, as part of the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex). A high-spectral-resolution lidar (HSRL) recorded a substantial increase in backscattered signal associated with high aerosol loading ∼440 m above the surface during the peak of firework activities around 00:00 (local time). This was accompanied by PM2.5 concentrations peaking at 383.9 µg m−3. During the firework event, water-soluble ions and elements, which affect particle formation, growth, and fate, were mostly in the submicrometer diameter range. Total (&gt;0.056 µm) water-soluble bulk particle mass concentrations were enriched by 5.7 times during the fireworks relative to the background (i.e., average of before and after the firework). The water-soluble mass fraction of PM2.5 increased by 18.5 % above that of background values. This corresponded to increased volume fractions of inorganics which increased bulk particle hygroscopicity, kappa (κ), from 0.11 (background) to 0.18 (fireworks). Potassium and non-sea-salt (nss) SO42- contributed the most (70.9 %) to the water-soluble mass, with their mass size distributions shifting from a smaller to a larger submicrometer mode during the firework event. On the other hand, mass size distributions for NO3-, Cl−, and Mg2+ (21.1 % mass contribution) shifted from a supermicrometer mode to a submicrometer mode. Being both uninfluenced by secondary aerosol formation and constituents of firework materials, a subset of species were identified as the best firework tracer species (Cu, Ba, Sr, K+, Al, and Pb). Although these species (excluding K+) only contributed 2.1 % of the total mass concentration of water-soluble ions and elements, they exhibited the highest enrichments (6.1 to 65.2) during the fireworks. Surface microscopy analysis confirmed the presence of potassium/chloride-rich cubic particles along with capsule-shaped particles in firework samples. The results of this study highlight how firework emissions change the physicochemical and optical properties of water-soluble particles (e.g., mass size distribution, composition, hygroscopicity, and aerosol backscatter), which subsequently alters the background aerosol's respirability, influence on surroundings, ability to uptake gases, and viability as cloud condensation nuclei (CCN).