1,721,199 research outputs found
Chemical speciation of PM2.5 collected in Belluno, Italy, during the 2020-2021 winter
No full textChemical speciation data of PM2.5 collected during the October 1, 2020–February 14, 2021 period in Belluno, Italy. Data used for the study: Masiol, M., Formenton, G., Visin, F., Bonetto, A., Rovea, M., Ficotto, S., Danesin, E., Toffanin, T., Maggiulli, A., Battistel, M. and Mazzi, G., 2024. Sources of wintertime PM2. 5 at a major city in an Alpine Valley: The role of atmospheric dispersion and inversion dynamics. Atmospheric Environment, 330, p.120556. https://doi.org/10.1016/j.atmosenv.2024.12055
Land-use regression modeling of wood smoke in Rochester, NY
No full textDuring the last decade, a substantial rise in the use of wood for space and water heating followed the increased cost of fossil fuels in Northern America. The use of this renewable source of energy has many
advantages related to the carbon cycling, greenhouse gas emissions and climate. However, emissions from wood combustion sources may seriously impact air quality. The relationships between wood
smoke exposure and health effects have been studied: epidemiology suggests that the toxicity of wood combustion particles is similar to urban particulate matter. During the 2015/16 heating season, ambient particulate matter (PM) concentrations were measured at 23 sites across the Monroe County using low-cost monitors. Data were corrected based on the results of previous calibration studies. The corrected data were assessed to have good reproducibility, 10% precision and 10 μg/m3 limit of detection. Most of the sites showed clear diurnal patterns with higher concentration in the late afternoon and evening hours. Weekly pattern were more variable, but a general decrease of concentrations was found during the weekends. The hourly and weekly patterns of PM were spatially interpolated. The results show that ambient PM concentrations are generally higher over the more densely urbanized areas of the county. Data were then used as input for a land use regression model. Raster surfaces (spatial resolution 10 x 10 m) were developed for a series of predictors which are potentially related to the concentration of PM, including number of bedroom, fireplaces, kitchens, property value, property year built, road type and road traffic densities, elevation and density of various land cover data features. Circular buffers were calculated around the 23 sampling sites with radius ranging from 50 m to 5000 m (50 m steps) and buffer statistics were computed. Pearson correlation coefficients were calculated between hourly and weekday averages of PM concentrations and the statistics of predictors for all the buffers. In general, the relationships between PM concentrations and the predictors are moderate and comparable with the results of previous studies. A Deletion/Substitution/Addition (D/S/A) algorithm was then used to maximize the prediction accuracy for locations without measurements
Caratterizzazione chimica del particolato atmosferico in Veneto: Dieci anni di studi
No full textLo studio della composizione del particolato atmosferico (PM) nel Veneto, accoppiato all'acquisizione dei dati meteorologici, ha offerto molte opportunità per comprendere gli andamenti stagionali e le sorgenti del particolato atmosferico. Un risultato ormai consolidato offerto da queste analisi mostra che durante il periodo invernale, così come gran parte della pianura padana, vi è una forte associazione tra le concentrazioni di PM con le sostanze strettamente legate alla combustione della biomassa legnosa. Inoltre risulta non trascurabile il contributo dell'aerosol secondario che è legato alle emissioni di precursori gassosi da traffico, combustioni per il riscaldamento residenziale. Al contrario durante il periodo estivo risulta molto più importante il contributo dovuto alla risospensione di materiale crostale e del "road dust". Gli interventi per la riduzione dell'inquinamento atmosferico nel corso degli anni si sono dimostrati spesso inefficaci perché non hanno inciso in modo drastico sulla riduzione delle sorgenti e non hanno modificato i comportamenti sociali su larga scala
Source apportionment in Veneto
No full textLo studio indaga le principali componenti di natura chimica, l'acidità e le principali sorgenti di PM2.5 in 6 città del Veneto. La speciazione chimica (carbonio organico ed elementare, 9 ioni, 18 elementi e 8 IPA) è stata analizzata in campioni di PM2.5 raccolti contemporaneamente in 6 siti urbani (Aprile 2012-Febbraio 2013): Belluno (BL), Conegliano (TV), Vicenza (VI), Mestre (VE), Padova (PD) e Rovigo (RO). Le componenti principali del PM2.5 sono state ricostruite utilizzando una “hybrid-multiple site-mass closure” che tiene conto della miscela di sali termodinamicamente favorita (comprese specie di aerosol secondario inorganico) stimata dal modello ISORROPIA-II. In media, la materia organica rappresenta la maggior parte della massa del PM2.5 (34%), seguita da materiale crostale (16%), solfati (solfato di ammonio, bisolfato di ammonio e Na-, Mg-, K-, Ca- solfati, 14%), nitrati (nitrato di ammonio e Na-, Mg-, K-, Ca- nitrati, 13%), carbonio elementare (5%), metalli, NaCl e altri sali (1%). Il 10% della massa residua è attribuita al contenuto di acqua calcolata dal modello termodinamico e ad altro materiale non spiegato dal modello (7%). L’aerosol è acido con un pH compreso tra 1,5 e 4,5 e mostra valori inferiori in estate. Sono state identificate e quantificate 6 sorgenti di emissione principali utilizzando un modello a recettore “multiple-site PMF” sui 5 siti della Pianura Padana (escluso BL). In media, il solfato secondario rappresenta il 34% della concentrazione di PM2.5, seguito da nitrato secondario (30%), combustione di biomassa (17%), traffico (11%), polvere risospesa (5%) e industrie (3%). Alla combustione di biomassa è possibile attribuire circa il 90% della produzione degli IPA totali. Una regressione lineare stepwise tra pH e sorgenti ha mostrato che l'acidità dell'aerosol è influenzata da solfato secondario, sorgente industriale (diminuzione del pH), nitrato secondario e combustione di biomassa (aumento del pH). Il modello “multiple-site concentration-weighted trajectory” è stato quindi utilizzato per rilevare le potenziali aree di origine delle due sorgenti secondarie, la combustione di biomassa, le emissioni industriali e l'acidità stimata. L'Europa centrale e orientale sono risultate le aree di origine principale per le sorgenti secondarie. Non sono state trovate aree di origine particolari per il pH. Questo studio fornisce informazioni chiave sulla qualità dell'aria in tutta l'Italia settentrionale, evidenziando le future esigenze di ricerca e i possibili sviluppi della rete di monitoraggio regionale
An overview of the project “CHEERS”: Chemical and Physical Properties and Source Apportionment of Airport Emissions in the context of European Air Quality Directives
No full textAircraft engine exhaust emissions and other airport-related contributions to ambient air pollution:A review
Full text linkCivil aviation is fast-growing (about+5% every year), mainly driven by the developing economies and globalisation. Its impact on the environment is heavily debated, particularly in relation to climate forcing attributed to emissions at cruising altitudes and the noise and the deterioration of air quality at ground-level due to airport operations. This latter environmental issue is of particular interest to the scientific community and policymakers, especially in relation to the breach of limit and target values for many air pollutants, mainly nitrogen oxides and particulate matter, near the busiest airports and the resulting consequences for public health. Despite the increased attention given to aircraft emissions at ground-level and air pollution in the vicinity of airports, many research gaps remain. Sources relevant to air quality include not only engine exhaust and non-exhaust emissions from aircraft, but also emissions from the units providing power to the aircraft on the ground, the traffic due to the airport ground service, maintenance work, heating facilities, fugitive vapours from refuelling operations, kitchens and restaurants for passengers and operators, intermodal transportation systems, and road traffic for transporting people and goods in and out to the airport. Many of these sources have received inadequate attention, despite their high potential for impact on air quality. This review aims to summarise the state-of-the-art research on aircraft and airport emissions and attempts to synthesise the results of studies that have addressed this issue. It also aims to describe the key characteristics of pollution, the impacts upon global and local air quality and to address the future potential of research by highlighting research needs.</p
Application of meteorology-based methods to determine local and external contributions to particulate matter pollution: A case study in Venice (Italy)
Full text linkThe air quality is influenced by the potential effects of meteorologyat meso- and synoptic scales. While local
weather and mixing layer dynamics mainly drive the dispersion of sources at small scales, long-range
transports affect the movements of air masses over regional, transboundary and even continental scales.
Long-range transport may advect polluted air masses from hot-spots by increasing the levels of pollution at
nearby or remote locations or may further raise air pollution levels where external air masses originate from
other hot-spots. Therefore, the knowledge of ground-wind circulation and potential long-range transports
is fundamental not only to evaluate how local or external sources may affect the air quality at a receptor site
but also to quantify it. This review is focussed on establishing the relationships among PM2.5 sources,
meteorological condition and air mass origin in the Po Valley, which is one of the most polluted areas in
Europe. We have chosen the results from a recent study carried out in Venice (Eastern Po Valley) and have
analysed them using different statistical approaches to understand the influence of external and local
contribution of PM2.5 sources. External contributions were evaluated by applying Trajectory Statistical
Methods (TSMs) based on back-trajectory analysis including (i) back-trajectories cluster analysis, (ii) po-
tential source contribution function (PSCF) and (iii) concentrationweighted trajectory (CWT). Furthermore,
the relationships between the source contributions and ground-wind circulation patterns were investi-
gated by using (iv) cluster analysis on wind data and (v) conditional probability function (CPF). Finally, local
source contribution have been estimated by applying the Lenschow' approach.
In summary, the integrated approach of different techniques has successfully identified both local and
external sources of particulate matter pollution in a European hot-spot affected by the worst air quality
Quantification of air quality impacts of London Heathrow Airport (UK) from 2005 to 2012
Full text linkAmong other emission sources in the Greater London area, the international airport of Heathrow is recognised to be a major source of air pollution and is one of the UK locations where European air quality Limit Values are currently breached. However it is very difficult to differentiate between pollutants arising from airport operations and those from the large volumes of road traffic generated by the airport, as well as the nearby M4 and M25 motorways, A4 and A30 major roads, the conurbation of London and other external sources. In this study, eight years (January 2005-December 2012) of measurements of various air pollutants (NO, NO2, NOx, O3, CO, PM10 and PM2.5) were investigated from 10 sites: eight sites are located within a distance of 2.5 km from the airport, while two sites representative of the regional background and of background air quality in London (Harwell (60 km WNW) and North Kensington (17 km ENE), respectively) were included. A series of statistical tools was thus applied to: (1) investigate the time series by analysing hourly data as diurnal, weekly, seasonal and annual patterns; (2) reveal the effects of the atmospheric circulation upon air pollution by analysing background-corrected polar plots and (3) quantify the impact of the airport upon air quality in the local area using the inter-site differences of measured concentrations. The results show different diurnal patterns in emissions of NOx from the airport and from the motorways. The concentration increment arising from passage of air across the airport during airport activity (6 am-10 pm) and with wind speed > 3 m s-1 is ca. 1-9 μg m-3 of NO2 and 2-20 μg m-3 of NOx at background stations. Such results are slightly lower than in a previous study analysing the 2001-2004 period. Air quality impacts of the M25 and M4 motorways are substantial only at the Hillingdon site (30 m from M4). Concentration increments of particulate matter can take either small positive or negative values.</p
PM2.5 source contributions at multiple-receptor sites using PMF analysis and weather data
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