Currently, there is no equipment to measure the real-time fit of EHMR or N-95masks which are used in harsh environments. Improper fit of these EHMRs or N-95 masks exposes the personnel to hazardous environments. Surface acoustic wave (SAW) sensors have been around for few decades and are being used in various applications. In this work, real-time PM2.5 detection using passive wireless SAW sensors is presented. The design of meander antenna at 433MHz for wireless interrogation of SAW sensor using HFSS and ADS is also presented in this thesis. This works also includes the design of YZ-lithium niobate SAW sensor including COMSOL simulation.

Les études internationales indiquent que la pollution atmosphérique présente des effets néfastes sur la santé. Au Liban, les taux de polluants atmosphériques dépassent les seuils recommandés par l’OMS et les législations sont presque absentes. Dans ce contexte, cette thèse tentera d’étudier les effets de l’exposition aux polluants de l’air sur la santé respiratoire, cardiaque et cutanée à Beyrouth en utilisant la méthodologie d’analyse des séries temporelles. Pour estimer l’effet de la pollution sur la santé de la population beyrouthine, nous avons principalement utilisé des données extraites des registres des urgences de sept hôpitaux ainsi que celles du réseau de surveillance de la qualité de l’air à Beyrouth et ce pour une période de dix-huit mois. L’analyse de régression, appliquée aux indicateurs de pollution, de santé et d’autres facteurs de confusion nous a permis de montrer une relation significative entre les admissions pour causes respiratoires, cardiaques et cutanées et l’augmentation des niveaux de polluants atmosphériques. Les analyses menées chez les enfants et les personnes âgées ont montré qu’il existe une relation significative entre les admissions aux urgences pour causes respiratoires et l’augmentation de la concentration des particules de 10µg.m-3 au-dessus des normes exigées et ceci au jour même. Cependant, nous avons montré qu’une association significative existe chez les adultes mais pour un délai de six à sept jours. La relation entre l’augmentation des niveaux de polluants et les admissions aux urgences pour causes cardiovasculaires n’a pas été très significative. Par contre une relation a été considérée positive et importante entre l’élévation des taux de polluants et les admissions aux urgences pour des maladies cutanées. En conclusion, nos résultats ont mis en évidence l’effet des polluants sur la santé des habitants à Beyrouth surtout chez des groupes vulnérables (enfants et personnes âgées) et ont souligné la nécessité de mener des études supplémentaires sur ce sujet. / International studies show that air pollution has adverse effects on health. In Lebanon, air pollutants exceed the limits recommended by WHO and laws barely exist. This thesis attempts to study the effects of exposure to air pollutants on respiratory, cardiovascular and skin diseases in Beirut using the methodology of time series analysis.To estimate the health effects of air pollution in Beirut, we mainly used data from emergency registers of seven hospitals as well as data from the air quality monitoring network in Beirut for a period of eighteen months. Regression analysis taking into consideration pollution and health indicators and other confounding factors allowed us to demonstrate a significant relationship between admissions for respiratory, cardiovascular and skin diseases and the increased levels of air pollutants. The analysis conducted in children and elderly groups apart have shown that there is a significant relationship, same day, between emergency admissions for respiratory causes and the increase in particles concentrations of 10μg.m-3. However, this significant association exists in adults group but for a delay of six to seven days. The relationship between increasing levels of air pollution and emergency admissions for cardiovascular causes was barely significant. Beside strong association was found between air pollutants and emergency admissions for skin diseases. In conclusion, our results proved the effect of air pollution on health in Beirut especially among vulnerable groups (children and elderly groups) and stressed the need to conduct additional studies on this subject.

Increasing PM2.5 (particulate matter smaller than 2.5 micrometers) poses a significant health risk to people. Understanding variables critical to PM2.5 spatial and temporal variation is a first step towards protecting vulnerable populations from exposure. Previous studies investigate variables responsible for PM2.5 variation but have a limited temporal span. Moreover, although land-use classes are often taken into account, the vertical environment's influence (e.g., buildings, trees) on PM2.5 concentrations is often ignored and on-road circle buffers are used. To understand variables most critical to PM2.5 concentration variation, an air pollution sensor and GPS unit were affixed to a bicycle to sample for variables over three seasons (spring, summer, fall). Samples were taken on a route during the weekdays at four targeted hours (7AM, 11AM, 3PM, and 7PM) and joined with meteorological data. 3D morphology was assessed using LiDAR data and novel wind-based buffers. Wind speed only, wind direction only, and wind speed and direction buffers were computed and compared for their performance at capturing micro-scale urban morphological variables. Zonal statistics were used to compute morphological indicators under different wind assumptions in seasonal ordinary least squares regression models. A comprehensive wind and buffer performance analysis compares statistical significance for spatial and temporal variation of PM2.5. This study identifies the best wind parameters to use for wind-based buffer generation of urban morphology, which is expected to have implications for buffer design in future studies. Additionally, significant exposure hotspots for UNT students to PM2.5 pollution are identified.

According to the World Health Organization, urban air pollution is a high public health priority due its linkage to cardio-pulmonary disease and association with increased mortality and morbidity (1, 2). Additionally, air pollution impacts climate change, visibility, and ecosystem health. The development of effective strategies for improving air quality requires accurate estimates of air pollutant emissions. In response to the need for new approaches to measuring emissions, we have designed a mobile Flux Lab for the Atmospheric Measurement of Emissions (FLAME) that applies a proven, science-based method known as eddy covariance for the direct quantification of anthropogenic emissions to the atmosphere. The mobile flux lab is a tool with novel, multifaceted abilities to assess air quality and improve the fidelity of emission inventories. Measurements of air pollutant concentrations in multiple locations at the neighborhood scale can provide much greater spatial resolution for population exposure assessments. The lab's mobility allows it to target specific sources, and plumes from these can be analyzed to determine emission factors. Through eddy covariance, the lab provides the new ability to directly measure emissions of a suite of air pollutants. We have deployed the FLAME to three different settings: a rural Appalachian town where coal transport is the dominant industry; schools in the medium-sized city of Roanoke, Virginia; and the large urban areas around Norfolk, Virginia, to measure neighborhood-scale emissions of air pollution. These areas routinely experience high ozone and particulate matter concentrations and include a diverse array of residential neighborhoods and industries. The FLAME is able to capture emissions from all ground-based sources, such as motor vehicles, rail and barge traffic, refuse fires and refueling stations, for which no direct measurement method has been available previously. Experiments focus on carbon dioxide (CO₂), the principal greenhouse gas responsible for climate change; nitrogen oxides (NOx), a key ingredient in ground-level ozone and acid rain; volatile organic compounds (VOCs), a second key ingredient in ozone and many of which are air toxics; and fine particulate matter (PM2.5), a cause of mortality, decreased visibility, and climate change. This research provides some of the first measurements of neighborhood-scale anthropogenic emissions of CO₂, NOx, VOCs and PM2.5 and as a result, the first opportunity to validate official emission inventories directly. The results indicate that a mobile eddy covariance system can be used successfully to measure fluxes of multiple pollutants in a variety of urban settings. With certain pollutants in certain locations, flux measurements confirmed inventories, but in others, they disagreed by factors of up to five, suggesting that parts of the inventory may be severely over- or underestimated. Over the scale of a few kilometers within a city, emissions were highly heterogeneous in both space and time. FLAME-based measurements also confirmed published emission factors from coal barges and showed that idling vehicles are the dominant source of emissions of air toxics around seven schools in southwest Virginia. Measurements from this study corroborate existing emission inventories of CO₂ and NOx and suggest that inventories of PM2.5 may be overestimated. Despite the tremendous spatial and temporal variability in emissions found in dense urban areas, CO₂ fluxes on average are very similar across the areas in this study and other urban areas in the developed world. Nevertheless, the high level of variability in spatial and temporal patterns of emissions presents a challenge to air quality modelers. The finding that emissions from idling vehicles at schools are likely responsible for creating hot spots of air toxics adds to the urgency of implementing no-idling and other rules to reduce the exposure of children to such pollutants. Ultimately, the results of this study can be used in combination with knowledge from existing emission inventories to improve the science and policies surrounding air pollution. / Ph. D.

Ambient and indoor air pollution is a major cause of premature mortality, and has been associated with more than three million preventative deaths per year worldwide. Most of these health impacts are from the effects from fine particulate matter. It is suspected that PM2.5 health effects vary by composition, which depends on the mixture of pollutants emitted by sources. This has led to efforts to estimate relationships between sources of PM2.5 and health effects. The health effects of PM2.5 may be preferentially dependent on specific species; however, recent work has suggested that health impacts may actually be caused by the net effect of the mixture of pollutants which make up PM2.5. Recently, there have been efforts to use source impacts from source apportionment (SA) studies as a proxy for these multipollutant effects. Source impacts can be quantified using both receptor and chemical transport models (RMs and CTMs), and have both advantages and limitations for their use in health studies. In this work, a technique is developed that reconciles differences between source apportionment (SA) models by ensemble-averaging source impacts results from several SA models. This method uses a two-step process to calculate the ensemble average. An initial ensemble average is used calculate new estimates of uncertainties for the individual SA methods that are used in the ensemble. Next, an updated ensemble average is calculated using the SA method uncertainties as weights. Finally, uncertainties of the ensemble average are calculated using propagation of errors that includes covariance terms. The ensemble technique is extended to include a Bayesian formulation of weights used in ensemble-averaging source impacts. In a Bayesian approach, probabilistic distributions of the parameters of interest are estimated using prior distributions, along with information from observed data. Ensemble averaging results in updated estimates of source impacts with lower uncertainties than individual SA methods. Overall uncertainties for ensemble-averaged source impacts were ~45 - 74%. The Bayesian approach also captures the expected seasonal variation of biomass burning and secondary impacts. Sensitivity analysis found that using non-informative prior weighting performed better than using weighting based on method-derived uncertainties. The Bayesian-based source impacts for biomass burning correlate better with observed levoglucosan (R2=0.66) and water soluble potassium (R2=0.63) than source impacts estimated using more traditional methods, and more closely agreed with observed total mass. Power spectra of the time series of biomass burning source impacts suggest that profiles/factors associated with this source have the greatest variability across methods and locations. A secondary focus of this work is to examine the impacts of biomass burning. First a field campaign was undertaken to measure emissions from prescribed fires. An emissions factor of 14±17 g PM2.5/kg fuel burned was determined. Water soluble organic carbon (WSOC) was highly correlated with potassium (K) (R2=.93) and levoglucosan (R2=0.98). Results using a biomass burning source profile derived from this work further indicate that source apportionment is sensitive to levels of potassium in biomass burning source profiles, underscoring the importance of quantifying local biomass burning source profiles. Second, the sensitivity of ambient PM2.5 to various fire and meteorological parameters in was examined using the method of principle components regression (PCR) to estimate sensitivity of PM2.5 to fire data and, observed and forecast meteorological parameters. PM2.5 showed significant sensitivity to PB, with a unit-based sensitivity of 3.2±1 µg m-3 PM2.5 per 1000 acres burned. PM2.5 had a negative sensitivity to dispersive parameters such as wind speed.

La pollution atmosphérique est le produit de fortes émissions de polluants (et de leurs précurseurs) et de conditions météorologiques défavorables. Les particules fines (PM2.5) sont l'un des polluants les plus dangereux pour la santé publique. L'exposition répétée ou prolongée à ces particules entraîne chaque année des maladies respiratoires et cardio-vasculaires chez les personnes exposées ainsi que des morts prématurées. L'évolution du climat dans les années à venir aura un impact sur des variables météorologiques (température, vents, précipitations, ...). Ces variables influencent à leur tour divers facteurs, qui affectent la qualité de l'air (émissions, lessivage par les précipitations, équilibre gaz/particule, ...). Si de nombreuses études ont déjà projeté l'effet du changement climatique sur les concentrations d'ozone, peu se sont intéressées à son effet sur les concentrations de particules fines, en particulier à l'échelle du continent européen. C'est ce que cette thèse se propose d'étudier. La circulation atmosphérique de grande échelle est étroitement liée aux variables météorologiques de surface. Par conséquent, il est attendu qu'elle ait également un impact sur les concentrations de PM2.5. Nous utilisons dans cette thèse une approche statistique pour estimer les concentrations futures de PM2.5 à partir d'observations présentes de PM2.5, de quelques variables météorologiques pertinentes et d'outils permettant de représenter cette circulation atmosphérique (régimes et types de temps). Le faible nombre d'observations journalières de PM2.5 et de ses composants en Europe nous a conduit à créer un jeu de données pseudo-observées à l'aide du modèle de qualité de l'air Polyphemus/Polair3D, puis à l'évaluer de façons opérationnelle et dynamique, afin de s'assurer que l'influence des variables météorologiques sur les concentrations de PM2.5 est reproduite de manière satisfaisante par le modèle. Cette évaluation dynamique d'un modèle de qualité de l'air est, à notre connaissance, la première menée à ce jour.Les projections de PM2.5 sur les périodes futures montrent une augmentation systématique des concentrations de PM2.5 au Royaume-Uni, dans le nord de la France, au Benelux et dans les Balkans, et une diminution dans le nord, l'est et le sud-est de l'Europe, en Italie et en Pologne. L'évolution de la fréquence des types de temps ne suffit pas toujours à expliquer l'évolution de ces concentrations entre les périodes historique et futures, car les relations entre circulation atmosphérique de grande échelle et types de temps, entre types de temps et variables météorologiques, et entre variables météorologiques et concentrations de PM2.5 sont amenées à évoluer dans le futur et contribuent à l'évolution des concentrations de PM2.5. L'approche statistique développée dans cette thèse est nouvelle pour l'estimation de l'impact du climat et du changement climatique sur les concentrations de PM2.5 en Europe. Malgré les incertitudes qui y sont associées, cette approche est facilement adaptable à différents modèles et scénarios, ainsi qu'à d'autres régions du monde et d'autres polluants. En utilisant des observations pour définir la relation polluant-météorologie, cette approche serait d'autant plus robuste

O processo de tratamento da madeira utiliza substâncias que geram compostos perigosos que podem contaminar os compartimentos ambientais. O presente estudo avaliou uma área sob influência da contaminação de solo proveniente das atividades de uma usina de tratamento de madeira desativada. A presença e o efeito de compostos mutagênicos em amostras ambientais foram utilizados como marcadores de exposição associada à avaliação de marcadores genéticos de efeito precoce em humanos, com foco em crianças como grupo sensível. Uma área 1750 m distante da usina, fora do quadrante dispersão preferencial atmosférica e em oposição à drenagem do local, foi utilizada como local de referência para a coleta de amostras e comparação. Extratos orgânicos de água de abastecimento, poeira de sótão e material particulado atmosférico fino (PM2,5) foram avaliados para mutagenicidade por meio do ensaio Salmonella/microssoma. Cobre (Cu), cromo (Cr), arsênio (As) e pentaclorofenol (PCP) foram quantificados em amostras de poeira do sótão. Os 16 Hidrocarbonetos Policíclicos Aromáticos (HPAs) prioritários foram avaliados nos extratos de PM2,5 e poeira do sótão. Crianças residentes no entorno da usina e na área de referência foram avaliadas quanto à presença de micronúcleos em amostras de sangue e mucosa oral, e danos primários no DNA, pelo ensaio cometa em linfócitos de sangue periférico. De acordo com a análise de metais, as residências perto da entrada da usina foram as mais afetadas. PCP foi identificado em amostras de poeira de sótão (0,49 mg/kg) e a concentração total de HPAs nesta matriz variou 0,40-13,31 mg/g, com maior dispersão. Todas as amostras de poeira do sótão em que a concentração total de HPAs estava acima de 2μg/g apresentaram resposta positiva para a atividade mutagênica. A contribuição dos HPAs para a mutagênese na poeira de sótão representou 10%, indicando que outros compostos podem contribuir para o efeito mutagênico. A atividade mutagênica e a concentração de HPAs nas amostras de PM2,5foram, de maneira geral, mais elevadas na área de risco, embora em alguns períodos de amostragem a área de referência atingiu valores semelhantes ou mesmo superiores. O efeito mutagênico e as concentrações de HPAs observados nas amostras de PM2,5 foram semelhantes aos valores encontrados em estudos que avaliaram áreas urbanas e com influência industrial. Extratos orgânicos de água de abastecimento não apresentaram mutagenicidade. As frequências de MN em linfócitos de sangue periférico e de células binucleadas na mucosa oral foram significativamente maiores no grupo de risco. Nos demais biomarcadores avaliados não foram observadas diferenças significativas entre os grupos. O conjunto de resultados indica a necessidade de novas avaliações utilizando grupo de referência menos suscetível às influências da área contaminada. O conjunto de dados coletados neste estudo indica a necessidade de uma avaliação mais cuidadosa dos biomarcadores individualmente e de um grupo de referência menos suscetível a influências da área contaminada. Apesar da ausência de diferenças significativas entre os grupos de risco e de referência em biomarcadores de danos no DNA avaliados em crianças, os resultados observados nas amostras de poeira de sótão e PM2,5 sugerem que a população esteve ou ainda está potencialmente exposta a substâncias capazes de causar efeitos adversos à saúde humana. / The mutagenic activity and the concentration of PAHs in PM2.5 samples were generally higher in the risk area, although in some periods the reference area has reached similar or even higher values. The mutagenic effect and the concentrations of PAHs recorded in the PM2.5 samples were similar to those found in studies that assessed areas of intense urban occupation and industrial influence. Organic extracts from supply water showed no mutagenicity. The MN frequencies in peripheral blood lymphocytes and binucleated cells of the oral mucosa were significantly higher in the risk group. No significant differences between children from the reference and risk area were observed in others genetic biomarkers assessed. The result set indicates the need for further evaluations using reference group less susceptible to the influences of the contaminated area. The set of data collected in this study indicates the need for a more cautious assessment of biomarkers individually, and a reference group less susceptible to influences from the contaminated area is necessary. Despite the absence of significant differences between the risk and reference groups in biomarkers of DNA damage assessed in children, the results in attic and PM2.5 samples suggest that the population was or is still potentially exposed to substances with strong negatives effects on human health.

A crescente introdução de variados poluentes em matrizes ambientais de áreas urbanas causa prejuízos ao ecossistema e dificulta as medidas de controle ambiental. Essas substâncias, após liberadas, se distribuem e interagem de acordo com suas características e as do meio receptor. Indicadores precoces de contaminação permitem a adoção de medidas preventivas aos danos causados pela poluição ambiental. O presente estudo teve por objetivo investigar a ação de substâncias genotóxicas em diferentes frações de material particulado atmosférico e solos, analisando a presença de contaminantes orgânicos e inorgânicos. Para este fim, foi empregado o ensaio Salmonella/microssoma em amostras de áreas urbanas caracterizadas como urbano-residencial e urbano-industrial, na cidade de Rio Grande, RS. Amostras de material particulado atmosférico (PTS e PM2,5) e de solo superficial (composição granulométrica total e fração <0,5mm) foram preparadas por diferentes métodos de extração. Este estudo apresenta uma primeira caracterização de PM2,5, através do ensaio Salmonella/microssoma, no Brasil. O estudo de extratos orgânicos e aquosos de PTS e PM2,5 evidenciou a presença de compostos metálicos na fração aquosa, potencialmente biodisponíveis, bem como maior risco de exposição associado à fração de compostos orgânicos das partículas finas. A mutagênese foi detectada, mesmo em amostras de particulados que se encontravam em conformidade com os parâmetros de qualidade recomendados. A análise das extrações ácidas dos solos mostrou que as chuvas da região podem atuar como rota de contaminação ambiental, com risco adicional na disponibilização de substâncias tóxicas nos eventos de precipitação ácida. O estudo mostrou que o emprego do solo com mínima alteração é mais apropriado para os ensaios de mutagênese. A utilização conjunta de diferentes métodos de extração de compostos orgânicos e inorgânicos permite uma avaliação integradora da qualidade de matrizes ambientais complexas, favorecendo a adoção de medidas preventivas para a proteção do ecossistema. / The increasing introduction of different pollutants into the environmental matrices of urban areas damages the ecosystem and makes it difficult to perform environmental control. After these substances are released, they are distributed and interact according to their own characteristics and those of the receiving environment. Early indicators of contamination allow measures to be adopted to prevent damage caused by environmental pollution. The purpose of this study was to investigate the action of genotoxic substances in different fractions of atmospheric particulate matter and soils, analyzing the presence of organic and inorganic contaminants. For this, the Salmonella/microsome assay was used on samples of urban areas characterized as urban-residential and urban-industrial, in the city of Rio Grande, RS. Samples of atmospheric particulate matter (TSP and PM2.5) and of surface soil (total grain size composition and fraction <0.5mm) were prepared using different extraction methods. This study presents a first characterization of PM2.5 in Brazil, through the Salmonella/microsome assay. The study of organic and aqueous extracts of TSP and PM2.5 showed the presence of potentially bioavailable metallic compounds in the aqueous fraction, as well as a greater risk of exposure associated with the fraction of organic compounds of the fine particles. Mutagenesis was detected even in samples of particulates that were in accordance the recommended quality parameters. Analysis of acid extractions from the soils showed that rainfall in the region may act as an environmental contamination route, with an additional risk of making toxic substances available in acid precipitation events. The study showed that the use of minimally altered soil is more appropriate for mutagenesis assays. The joint use of different methods for organic and inorganic compound extractions allows an integrated evaluation of the quality of complex environmental matrices, favoring the adoption of preventive measures to protect the ecosystem.

Introduction: The attention on environmental impact on human health is rising. But, the association between particulate matter 2.5 and birth weight is still not acknowledged in the global burden of diseases, and the association has not yet been studied in the Philippines. The aim was to explore how increasing/decreasing concentrations of particulate matter 2.5 in pregnant women’s residence area was associated with the risk of having a child with low birth weight in the Philippines. Method: 1462 women pregnant in 2016 from the Demographic and Health Survey done in the Philippines in 2017 were analyzed by exposure to particulate matter 2.5 in their residence area. Particulate matter 2.5 was derived from the DIMAQ model, which estimated the annual mean exposure based on a mix of methods. A logistic regression adjusted for demographic variables and variables important for fetal growth, and the birth season was done. Results: The results of the logistic regression when adjusted for all variables showed that the non-statistically significant odds of low birth weight in the children from to the particulate matter 2.5 categories: 7-10 μg/m3, 11-14 μg/m3, and 15-18 μg/m3 were respectively 21% lower (CI: 0.42-1.50), 33% lower (CI: 0.39-1.21) and 34% lower (CI: 0.39-1.14) compared to the highest exposure category of 19-22 μg/m3. Discussion: The study had several limitations in regard to the study design, especially in dealing with seasonal changes in low birth weight. Yet, the study did not disagree with the results from similar studies done in other countries or globally.

La contaminació atmosfèrica és un problema de salut pública, causa més de 380 000 morts a la Unió Europea. La present tesis té per objectius avaluar l'exposició i efectes sobre el tracte respiratori de la contaminació provinent del tràfic. Les concentracions exteriors y personals de sulfurs i de carbó són bons indicadors de exposició personal en una ciutat mediterrània; per a PM2.5 hi ha altres fonts a considerar. La molèstia deguda a la contaminació no és un bon indicador d'exposició, però reflecteix la percepció del subjecte. La contaminació que prové del tràfic augmenta els símptomes d'asma y probablement també causa asma en adults. El PM2.5 provinent de la combustió augmenta la permeabilitat de la barrera epitelial pulmonar. El tràfic és una font important de contaminació. Es requereixen eines adequades per a mesurar la seva exposició. La contaminació del tràfic es un factor de risc important per a la salut respiratòria. / La contaminación atmosférica es un problema de salud pública, causa 380 000 muertes anuales en la Unión Europea. Esta tesis tiene como objetivo evaluar la exposición a la contaminación debida al tráfico y sus efectos en la salud respiratoria. Los niveles diarios de carbón y sulfuro medidos centralmente son buenos indicadores de exposición personal en una ciudad mediterránea, para PM2.5 fuentes de emisión alternas se tienen que considerar. La molestia debida a la contaminación no es un marcador de exposición, pero es importante porque refleja las percepciones individuales. La contaminación proveniente del tráfico aumento los síntomas del asma, y probablemente también causa asma en adultos. El PM2.5 proveniente de la combustión aumenta la permeabilidad de la barrera epitelial pulmonar. El tráfico es una fuente importante de la contaminación. Herramientas adecuadas para medir su exposición son requeridas. La contaminación del tráfico es un factor de riesgo importante para la salud respiratoria. / Air pollution is a major public health concern causing annually 380 000 deaths in the European Union. This thesis aims to study traffic-related air pollution exposure assessment and its association with respiratory effects. Daily levels of carbon and sulphur of outdoor central measurements are good surrogates for personal exposure in a Mediterranean setting; for PM2.5 other sources have to be taken into account. Annoyance due to air pollution is not a valid maker of air pollution exposure but is valuable in its own right as it integrates individual perceptions. Traffic-related air pollution increases asthma symptoms in adults and an association with new asthma onset is suggested. Furthermore, PM2.5 from combustion might lead to an increase in the lung's epithelial barrier permeability. Traffic-related air pollution is a major source of pollution. Adequate tools to assess its exposure are still needed. Traffic-related air pollution is an important risk factor for respiratory morbidity.