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Impact of bicycle route type on exposure to traffic-related air pollution

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... This is a difficult phenomenon to measure, being integrated into the models through indirect indicators. More often, it is the type of axis on which the measure is taken (Dons et al., 2013;Farrell et al., 2015;MacNaughton, Melly, Vallarino, Adamkiewicz, & Spengler, 2014). The underlying assumption is that major axes support a higher volume of vehicles than minor axes. ...
... On a more micro scale, many studies also integrate characteristics relative to the street's configuration, such as density of buildings (Apparicio et al., 2016), streetcanyon (Dekoninck et al., 2013;Krecl et al., 2019;Van den Bossche et al., 2018), number of intersections (Apparicio et al., 2016;MacNaughton et al., 2014), presence of vegetation (MacNaughton et al., 2014), and slope (Gelb & Apparicio, 2019). However, we still do not have enough cases of application to come to a consensus. ...
... On a more micro scale, many studies also integrate characteristics relative to the street's configuration, such as density of buildings (Apparicio et al., 2016), streetcanyon (Dekoninck et al., 2013;Krecl et al., 2019;Van den Bossche et al., 2018), number of intersections (Apparicio et al., 2016;MacNaughton et al., 2014), presence of vegetation (MacNaughton et al., 2014), and slope (Gelb & Apparicio, 2019). However, we still do not have enough cases of application to come to a consensus. ...
Article
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Cyclists constitute a population particularly exposed to atmospheric and noise pollution in urban environments; at the same time, they contribute to its reduction. For about ten years now, more and more studies have been completed to assess cyclists’ exposure, comparing this mode of transportation with others, quantifying its impacts in term of individual and collective health, understanding cyclists’ perceptions regarding their exposure, etc. Though some literature reviews have examined some of these specific issues, none have yet proposed a general overview of this field of study. Therefore, this mapping literature review fills this gap by jointly analysing 205 articles and identifying elements of consensus and disagreement, as well as existing gaps. Among others, our results indicate that the cities in the South and exposure to noise are under-studied and that cyclists’ ventilation is still too rarely accounted for, regardless of the type of studies. Modelling studies regarding exposure are too heterogeneous methodologically to allow a generalisation of their results. Conversely, intermodal comparison studies clearly indicate overexposure for cyclists compared to other modes. Also, health studies conclude that, either individually or collectively, the benefits of cycling surpass the costs of exposure to atmospheric pollution. The knowledge produced by this research trend remains difficult to exploit by urban planners, but the recent work done seems to offer more practical perspectives to professionals.
... First, road traffic might be measured as real time traffic recorded specifically during the time span of the study [32,33], estimations of daily traffic volume [34][35][36], or the type of roads taken by the cyclist [19,28,29]. In all cases, road traffic is associated with cyclists' greater exposure to air and noise pollution. ...
... Second, vegetation is integrated in studies as the number of trees around the samples [19,36], the presence of a park [20,[35][36][37], or its density [34]. The results remain inconsistent and the role of vegetation in the absorption and deposit of air and noise pollution seems to be small in comparison with the "park effect" induced by the increased distance from pollution sources. ...
... Moreover, these stations are generally not located directly on streets, but some meters above the ground or on the top of buildings, which contributes to an underestimation of people's direct exposure at road level [47,52,53]. MacNaughton et al. [34] reports values for NO 2 (ppb) of 24.2 ppb measured by mobile sensors (sampled concentration) versus 15.9 ppb by static stations (background pollution) on a designated bike lane. Different authors likewise observed higher variations for other pollutants [20,54,55]. ...
Article
Cyclists are particularly exposed to air and noise pollution because of their higher ventilation rate and their proximity to traffic. However, few studies have investigated their multi-exposure and have taken into account its real complexity in building statistical models (nonlinearity, pseudo replication, autocorrelation, etc.). We propose here to model cyclists' exposure to air and noise pollution simultaneously in Paris (France). Specifically, the purpose of this study is to develop a methodology based on an extensive mobile data collection using low-cost sensors to determine which factors of the urban micro-scale environment contribute to cyclists' multi-exposure and to what extent. To this end, we developed a conceptual framework to define cyclists' multi-exposure and applied it to a multivariate generalized additive model with mixed effects and temporal autocorrelation. The results show that it is possible to reduce cyclists' multi-exposure by adapting the planning and development practices of cycling infrastructure, and that this reduction can be substantial for noise exposure.
... Also using AE51, the concentration of BC was measured on six equal routes in Stockholm -Sweden, by Merritt et al. (2019), on a 12 km route in Stuttgart -Germany (Samad and Vogt, 2021) and in Antwerp -Belgium (Van den Bossche et al., 2018). MacNaughton et al. (2014) studied the concentrations of BC along five bike routes in Boston, Massachusetts. Alas et al. (2019) on the two: 5.5 and 5 km, route in Metro Manila -Philipines. ...
... The concentration of BC on sections of routes running along roads (especially main roads) are several or even a dozen or so times higher than when they run through green areas. MacNaughton et al. (2014) reports that bike lines have BC concentration approximately 33% higher than bike paths. Around 1 μgm − 3 of atmospheric BC could be attributed to urban emission, whereas traffic contributed up to 8 μgm − 3 of atmospheric BC near busy roads (Singh et al., 2018). ...
Article
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Studying the air quality and exposure of the inhabitants of urban agglomerations to pollution is the basis for the creation and development of more sustainable cities. Although research on black carbon (BC) has not yet reached the official acceptable levels and guidelines, the World Health Organization clearly indicates the need to measure and control the level of this pollutant. In Poland, monitoring of the level of BC concentration is not included in the air quality monitoring network. To estimate the extent of this pollutant to which pedestrians and cyclists are exposed, mobile measurements were carried out on over 26 km of bicycle paths in Wrocław. The obtained results indicate the influence of urban greenery next to the bicycle path (especially if the cyclist is separated from the street lane by hedges or other tall plants) and the 'breathability' (i.e., associated with surrounding infrastructure) of the area on the obtained concentrations; the average concentration of BC in such places ranged from 1.3 to 2.2 μg/m3, whereas a cyclist riding directly on bike paths adjacent to the main roads in the city center is exposed to concentrations in the range of 2.3-14 μg/m3. The results of the measurements, also related to stationary measurements made at a selected point of one of the routes, clearly indicate the importance of the infrastructure surrounding the bicycle paths, their location, and the impact of urban traffic on the obtained BC concentrations. The results presented in our study are based only on short-term-field campaigns preliminary studies. To determine the quantitative impact of the characteristics of the bicycle route on the concentration of pollutants, and thus the exposure of users, the systematized research should cover a greater part of the city and be representative in terms of various hours of the day.
... In addition, with the implementation of the bike sharing, the use of personal motorcycles has decreased by 46% in Berlin (Hitchcok and Vedrenne, 2014). Therefore, policy making towards the development of pedestrians and the implementation of the bike sharing by urban managers is one of the effective solutions that have been proposed in previous studies to reduce urban pollution (Hertel et al., 2008;MacNaughton et al., 2014;Vlachokostas et al., 2011). ...
... Also, the limitations of the present study and prospects for future studies are as follows: (Hertel et al., 2008;MacNaughton et al., 2014;Vlachokostas et al., 2011) A 2 Expansion of parking lots Agyapong and Ojo, 2018;Vlachokostas et al., 2011) A 3 Policies related to shift from Fossil Fuels to Clean Energy (Aien and Mahdavi, 2020;Shahsavari and Akbari, 2018;Vlachokostas et al., 2011) A 4 International cooperation with dust-prone neighboring countries (Ataei and Norouzi, n.d.;Khoshnevisan et al., 2019;Pournabi et al., 2021) A 5 Regular maintenance of heavy oil burners Vlachokostas et al., 2011) A 6 Controlling local dust sources by mulching (Clement et al., 2021;Khojasteh et al., 2017) A 7 Urban green belt plan (Islam et al., 2012;Pournabi et al., 2021) (Golchin et al., 2018)( Madanian andCosta, 2017) A 8 Limiting of cropping for environmental restoration and import of virtual water (Lv et al., 2020;Pournabi et al., 2021) A 9 Environmental taxes Vlachokostas et al., 2011) A 10 Roadways infrastructure expansion Vlachokostas et al., 2011) S.S. Hosseini Dehshiri and B. Firoozabadi • In the present study, 5 different types of RR phenomena were investigated in different decision-making methods. However, there are many RR-free methods in the literature that can be examined in terms of different types of RR. • In the current study, a new approach based on WIL was presented and it was shown that the use of this approach significantly reduces the occurrence of RR in TOPSIS, ARAS, WASPAS, EDAS, CODAS and MARCOS methods. ...
Article
In the present study, a novel approach based on multi-criteria analysis was proposed to prioritize PM mitigation strategies from economic, environmental and social aspects. Multi-criteria decision making (MCDM) methods are suitable tools for prioritizing strategies on various topics. However, it has been observed that adding/removing strategies has led to a change in preference which is called rank reversal. The present study was aimed with three objectives: (i) evaluating the rank reversal phenomenon in MCDM methods frequently used in environmental topics, (ii) introducing a novel approach based on wins in league (WIL) in order to reduce the rank reversal in MCDM methods and (iii) a new application of this method in prioritizing PM mitigation strategies in arid urban areas. Qualitative results showed that in studies in the field of environment, the rank reversal has occurred frequently in classical MCDM methods but its occurrence was prevented in the proposed method. Quantitative evaluation also showed that the probability of rank reversal occurrence in Technique For Order Performance By Similarity To Ideal Solution (TOPSIS), Additive Ratio ASsessment (ARAS), Weighted Aggregated Sum Product Assessment (WASPAS), Evaluation Based On Distance From Average Solution (EDAS), Combinative Distance-Based Assessment (CODAS) and Measurement Alternatives and Ranking According to Compromise Solution (MARCOS) methods was 36.4%, 32.8%, 21.2%, 31.6%, 36.1% and 29.9%, respectively. However, the probability of rank reversal occurrence in the proposed approach was almost 90% less than classical MCDM methods. Evaluation of PM mitigation strategies in arid urban areas has also shown that urban green belt plan is the most appropriate strategy.
... Also using AE51, the concentration of BC was measured on six equal routes in Stockholm -Sweden, by Merritt et al. (2019), on a 12 km route in Stuttgart -Germany (Samad and Vogt, 2021) and in Antwerp -Belgium (Van den Bossche et al., 2018). MacNaughton et al. (2014) studied the concentrations of BC along five bike routes in Boston, Massachusetts. Alas et al. (2019) on the two: 5.5 and 5 km, route in Metro Manila -Philipines. ...
... The concentration of BC on sections of routes running along roads (especially main roads) are several or even a dozen or so times higher than when they run through green areas. MacNaughton et al. (2014) reports that bike lines have BC concentration approximately 33% higher than bike paths. Around 1 μgm − 3 of atmospheric BC could be attributed to urban emission, whereas traffic contributed up to 8 μgm − 3 of atmospheric BC near busy roads (Singh et al., 2018). ...
... The Geographical Bulletin © 2020 Gamma Theta Upsilon As individuals look for ways to decrease their carbon footprint, many are turning to alternative forms of transportation, with cycling at the forefront (Apparicio, et al. 2016). This increase in cycling popularity is especially prevalent near universities in the United States and Canada (MacNaughton, et al. 2014;Pucher et al., 2011). Not only does cycling contribute to reductions in carbon dioxide and particulate matter (PM) emissions but cycling also benefits riders with positive health gains via physical activity (Rojas-Rueda, et al. 2011). ...
... To avoid PM2.5 hotspots, cyclists can vary their routes, and the time of their commute. For example, cyclists can reduce their exposure to harmful PM2.5 pollution by 33% by using only designated bike paths instead of shared roadways (MacNaughton et al., 2014). Harmful exposure can also be avoided by commuting at times with lower traffic density. ...
Article
Full-text available
Although cycling has environmental and health benefits, urban cyclists are at risk of exposure to harmful concentrations of fine particulate matter (PM2.5). We used a low-cost particle sensor and MapMyRide to collect geolocated 1-minute PM2.5 measurements along four routes surrounding an urban university campus. Measurements were collected from 7:30-9:30 AM during fall 2017 and spring 2018. We found no significant differences in ride-averaged PM2.5 concentrations among routes, but all routes experienced higher concentrations when winds blew from the southeast-south-southwest. Hotspots, areas with consistently elevated PM2.5 concentrations compared to surrounding areas, were detected along all routes in areas with high traffic density and major signalized intersections. The highest PM2.5 concentrations occurred after 8:30, likely due to increased vehicular traffic. Understanding PM2.5 variability in urban areas is crucial to allow cyclists to better determine routes to avoid exposure to harmful levels of PM2.5.
... Bike paths or routes separated from motor traffic lanes had lower levels of air pollutants [66,67]. The use of designated off-road cycle tracks versus on-road bicycle paths reduced cyclist exposure to air pollutants [43,[67][68][69], and use of sidewalks and off-road bicycle lanes separated by 7 and 19 m from the roadways resulted in significantly lower exposure than on the road [69]. ...
... Bike paths or routes separated from motor traffic lanes had lower levels of air pollutants [66,67]. The use of designated off-road cycle tracks versus on-road bicycle paths reduced cyclist exposure to air pollutants [43,[67][68][69], and use of sidewalks and off-road bicycle lanes separated by 7 and 19 m from the roadways resulted in significantly lower exposure than on the road [69]. The use of designated off-road footpaths and cycle tracks may be considered in community-level interventions (figure 2). ...
Article
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As global awareness of air pollution rises, so does the imperative to provide evidence-based recommendations for strategies to mitigate its impact. While public policy has a central role in reducing air pollution, exposure can also be reduced by personal choices. Qualified evidence supports limiting physical exertion outdoors on high air pollution days and near air pollution sources, reducing near-roadway exposure while commuting, utilising air quality alert systems to plan activities, and wearing facemasks in prescribed circumstances. Other strategies include avoiding cooking with solid fuels, ventilating and isolating cooking areas, and using portable air cleaners fitted with high efficiency particulate air filters. We detail recommendations to assist providers and public health officials when advising patients and the public regarding personal-level strategies to mitigate risk imposed by air pollution, while recognising that well-designed prospective studies are urgently needed to better establish and validate interventions that benefit respiratory health in this context.
... El transporte urbano es una de las dimensiones fundamentales que permiten el desarrollo de gran parte de las operaciones logísticas de las personas dentro de las ciudades. En este enfoque, el desarrollo y despliegue eficiente de sistemas de transporte se vuelve altamente relevante para la planificación urbana, así como el uso eficiente de la energía y la disminución de gases de tipo invernadero [1], [2]. De acuerdo con [3], [4] existen 6 componentes principales que permiten la transición y/o desarollo de un territorio urbano hacia una smart city, los cuales corresponden a: (1) Smart Economy, (2) Smart People, (3) Smart Governance,(4) Smart Mobility,(5) Smart Environment y (6) Smart Living, cabe destacar que cada uno de estos componentes se pueden desarrollar de forma independiente, sin embargo el desarrollo paralelo de los componentes es fundamental para el crecimiento sustentable y sostenible de una smart city. ...
Conference Paper
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En el presente artículo se expone un modelo de programación entera (MIP) que permite resolver el problema de rebalanceo de inventario (BRP) para un sistema de bicicletas compartidas. Una de las componentes más relevantes para las actividades de los ciudadanos en una smartcity corresponde a smart mobility, la que a su vez agrupa a distintos sistemas de transportes, tecnologías e infraestructuras. Sin embargo, uno de los sistemas de transporte a que ha tenido un creciente interés y desarrollo en la literatura en los últimos años corresponde al análisis y modelamiento de sistemas de bicicletas compartidas, debido a que estos permiten disminuir los tiempos de traslado, reducción de gases de tipo invernadero y aumentar la eficiencia de uso del espacio en transporte urbano, cabe destacar que estos son aspectos claves que inciden en la planificación de ciudades. En Chile se han desplegado diversos sistemas de bicicletas compartidas, algunos de los que presentan mayor notoriedad corresponden a Mobike y Bike Santiago, este último tiene una presencia de 7 años en el país. Sin embargo, uno de los principales problemas que inciden en la operación diaria de estos sistemas corresponde al rebalanceo de inventario (BRP). Para el problema BRP se propone un modelo de programación entera que busca minimizar la distancia total de rebalanceo para un sistema de bicicletas compartidas compuesto por 20 estaciones con capacidad fija. Dentro de los resultados más relevantes, estos sugieren que a medida que se flexibiliza la capacidad de inventario en cada estación, la distancia total de rebalanceo disminuye, naturalmente el sistema presenta límites para la flexibilización de inventario el cual se encuentra delimitado por la capacidad de cada estación.
... Numerous mobile campaigns using cars, bicycles and pedestrians have been widely performed (Apparicio et al., 2021;Samad and Vogt, 2020;Singh et al., 2021;Solomon et al., 2020). The use of low-cost sensors breathe new life into such studies as they can be more versatile and widely applied (Chatzidiakou et al., 2019;deSouza et al., 2020;Macnaughton et al., 2014;Wang et al., 2021b). Specifically, laser scattering PM sensors are considered suitable for mobile monitoring as they can record the fast temporal changes in PM concentrations (Buehler et al., 2021;Bulot et al., 2020). ...
... The advantages of mobile measurements using a bicycle are zero self-emissions of the vehicle, accessibility to nonroad areas, and visualization at a high spatial resolution with a low driving speed and high temporal resolution. In addition to the strong impacts of vehicle exhaust emissions on neighborhood-scale air quality [17][18][19][20], air pollutants emitted from domestic woodburning sources [21] and construction sites [22,23] have also been successfully detected using bicycle-based mobile platforms. Thus, mobile monitoring using a bicycle enables us to identify air pollution hotspots around different emission sources in a neighborhood-scale urban area. ...
Article
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Mobile measurement techniques are increasingly utilized to monitor urban emissions, regional air quality, and air pollutant exposure assessments. This study employed a bicycle measurement method to obtain the detailed distribution of air pollutant concentrations in roadside, commercial, residential, and recreational areas. The study area is located in Chuncheon, South Korea, with approximately 280,000 residents. Black carbon (BC), PM2.5, and NO2 were monitored using portable devices equipped on an electric bicycle. Results showed that in the evening (6–8 p.m.), the concentrations were higher in both commercial and residential areas compared to the background location, while concentrations were notably elevated only in roadside areas in the morning (8–10 a.m.). Spatial mapping of measured concentrations revealed that the highest concentrations corresponded to areas with densely operated charbroiling meat-cooking restaurants. Additionally, it was confirmed that BC and PM2.5 emitted from the commercial areas influenced nearby recreational areas (e.g., streamside roads). In conclusion, this study demonstrated that air pollutant hotspots resulting from human activities, such as dining at commercial restaurants, significantly worsen the local air quality on a small scale. Efforts to reduce the uncontrolled emissions of air pollutants from charbroiling meat-cooking restaurants are necessary.
... Heavy traffic intersections, underpasses, roundabouts and bus stops where vehicles start and accelerate frequently tend to manifest the highest concentrations, exposing cyclists to even greater risk due to long wait times (Qiu et al., 2019). Additionally, vegetation acts as a buffer between cyclists and vehicles, providing further protection against exposure (MacNaughton et al., 2014). ...
... For instance, the public tend to perceive air pollution as less serious when the activity's benefits outweigh its harms, such as outdoor running or cycling (Starr, 1969;Bickerstaff, 2004;Hodgson and Hitchings, 2018). However, research has revealed that cycling lanes located near main roads have significantly higher concentrations of BC and NO 2 compared to cycling lanes that are separated from motor vehicle traffic (MacNaughton et al., 2014). Moreover, studies have indicated that due to higher inhalation rates resulting from physical activity, cyclists tend to inhale higher concentrations of PM compared to both car drivers and pedestrians, when controlling for other relevant factors (Boniardi et al., 2021). ...
Article
Air pollution perception biases hinder the public's awareness of actual air quality. Past studies that examined the association and mismatch between actual and perceived air quality neglected individuals’ dynamic exposure and their activity, travel, spatial, temporal, and social contexts. Using data collected with real-time air pollutant sensors and ecological momentary assessment (EMA), this study investigated the association and mismatch between momentary air pollution exposure and perceived air quality. It also examined how activity type, travel mode, spatial and temporal contexts, and social factors contribute to this disparity. The results show that exposure to air pollution is significantly higher in residential areas (1.777 μg/m3) and transportation land-use areas (2.863 μg/m3) compared to commercial areas. Exposure in the evening is 1.308 μg/m3 higher than in the afternoon. Working or studying activities are associated with 2.863 μg/m3 lower exposure, and individuals perceive air quality as good when working or studying and in residential areas. Conversely, individuals assess air quality as poor in railway travel contexts and being accompanied by friends. This study also reveals the nonstationary association between air pollution exposure and perceived air quality. The odds of underestimating air pollution are 1.8–2.7 times as high as that in residential areas and 2.1 to 2.6 times that in transportation land-use areas when compared to commercial areas. Implementing targeted mitigation measures in these contexts can enhance public awareness of air pollution.
... Greater access to urban infrastructure, such as separated bicycle lanes and bicycle-sharing systems, creates commuting opportunities for cyclists (Apparicio et al., 2021;Schepers et al., 2015). Cycling, when compared to car rides, has the potential to increase people's physical activity (Cole et al., 2018;Rojas-Rueda et al., 2012), reduce pollution emissions from motor vehicles (Luengo-Oroz and Reis, 2019; Rabl and de Nazelle, 2012), and reduce traffic congestion in cities (MacNaughton et al., 2014). ...
... It has also been suggested that well-designed and appropriate cycling infrastructure can provide a safer environment for cyclists. Therefore, in countries where cycling is adequately promoted, the reduction of cycling accidents can be achieved [27][28][29][30]. ...
Article
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The parameters that affect bicyclists’ satisfaction are of vital importance when it comes to determining the reasons that endure bicycle usage in an urban environment. This research refers to the factors that affect bicycle users’ satisfaction with the existing infrastructure in the Municipality of Thessaloniki, Greece. Bicycle dependence in Thessaloniki is relatively limited when it is compared to other European cities with similar topological and demographic characteristics. This article aims to determine the most suitable measures that policymakers should implement to enhance bicycle infrastructure. The data collection process was realized through an online questionnaire survey addressed to the bicycle organizations and groups that are situated in Thessaloniki. Inferential statistical analysis investigated the dependency between the perceived satisfaction and the perceived level of safety of cyclists. Ordinal and multinomial logistic regressions were applied to identify the significant problems that influenced cyclists’ satisfaction, as well as the most important improvement measures suggested by the survey participants. The findings revealed that the lack of safety and urban integration of bicycle infrastructures were the statistically significant issues affecting users’ satisfaction. The development of a safe, integrated, and interconnected bicycle network area emerges as a priority to increase cyclists’ satisfaction and daily bicycle trips in cities with low bicycle culture.
... To prevent that physically separated pathways can be provided for pedestrians and cyclists. Preferably, these pathways should be away from motorized traffic or with a green barrier, to ensure their safety and lesser exposure to vehicular emissions (MacNaughton et al., 2014;Gallagher et al., 2015). In the current study, the modal share of NMT is 7.65%, the establishment of segregated pathways for cyclists is expected to lead to a higher modal share of non-motorized transportation, which would, in turn, contribute to reducing air pollution exposure. ...
Article
Introduction: Deteriorating air quality has a severe impact on human health that urges humans to make choices that can reduce their exposure. This study aims to explore the commuters' perception of how they perceive air quality information and the change in their travel choices to reduce air pollution exposure if air pollution information is provided. Methods: To comprehend the objectives, data was collected from commuters in Delhi using face-to-face questionnaire surveys through an open-source data collection platform. Results: The study findings show that only half of the respondents are aware of the air quality index but do not understand it. Commuters' preference for air pollution exposure in their decision-making for travel is the least, and the lack of any information intervention is the main reason for it. With the availability of information, commuters prefer close transport modes (car, bus, and metro) during severe air quality levels. Conclusion: This finding shows the importance of real-time information in commuters' decision-making, and due to the unavailability of any information concerning air pollution exposure, commuters cannot make any decisions that can reduce their exposure during travel.
... Here, we refer to a street canyon (or urban canyon) as where the road is flanked by buildings on both sides; a combination of narrow streets and tall buildings typical in cities. Cyclists can be separated from cars on bicycle paths specifically designed to greatly reduce the amount of pollution inhaled. Macnaughton et al. (2014) investigates the impact of different types of bicycle routes on the exposure to vehicle emissions, it is found that bicycle paths separated from traffic have much lower exposure rates than bicycle lanes sharing the road with cars. This is found to be true regardless of the traffic conditions adjacent to the route and paths separated from the traffic should therefore be encouraged. ...
Article
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A series of wind tunnel experiments were conducted in the University of Surrey's Environmental Flow wind tunnel with a 1:50 scale of a typical London street canyon to assess the exposure of cyclists riding in a group to the emissions of polluting vehicles. A propane source emitted from an Ahmed body was used to model a car exhaust and a fast flame ionisation detector was used to measure pollutant concentration around four cyclists for multiple configurations of the source, cyclists, and wind directions. Two cases were investigated with a vehicle driving in front of a line of cyclists and adjacent to them (as if it were overtaking them). In the first case, for small wind incidence, findings confirm that the cyclists exposure decreases exponentially with their distance from the source with a small dependence on wind direction but largely independently of the riders position within the group. For large wind incidences, typical of urban canyons, the rider position within the group becomes more important. For the second set of experiments, with the vehicle positioned adjacent to the riders, it was found to be preferable for a rider to be in front of the group regardless of the distance from the source, as this results in lower exposure to pollutants. This is likely linked with the complex aerodynamic field generated by the group of riders that can trap the vehicle exhaust fumes amongst the cyclists, hence increasing the exposure. This research suggests that group riding should be considered when designing mitigation strategies to minimise cyclists exposure to road traffic pollution within urban environments, where busy and narrow cycle lanes often results in cyclists riding in line.
... Neben dem Verkehr können weitere anthropogene Faktoren wie die Merkmale der städtischen Umgebung Einfluss auf die Schadstoffbelastung für Radfahrende nehmen. Ein Hauptmerkmal ist diesbezüglich die Architektur entlang der Verkehrsstraßen [9,25,26,32]. Die Straßenkonfiguration wird durch eine Reihe von charakteristischen Parametern definiert, die Einfluss auf die räumliche Variabilität der Schadstoffemissionen nehmen können. Hierzu zählen die Straßenbreite, die Ausrichtung der Straße, die Gebäudehöhe sowie die Bebauungsdichte und Freiluftschneisen entlang der Straße einschließlich der Länge des betrachteten Straßenabschnitts [7]. ...
Article
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Zusammenfassung Fahrradfahren als Form der aktiven Fortbewegung bietet viele gesundheitliche Vorteile durch eine gesteigerte körperliche Aktivität. In städtischer Umgebung können diese Vorteile aufgrund der intensivierten Respiration beim Radfahren und der Nähe zum Fahrzeugverkehr mit einer assoziierten Exposition von verkehrsbedingter partikulärer Luftverschmutzung durch Feinstaub beeinträchtigt werden. Das Ziel dieser Übersichtsarbeit ist, eine Darstellung der aktuellen Literatur mit mobil erhobenen Daten zur Feinstaubbelastung Radfahrender im urbanen Raum zu geben sowie die darin beschriebenen Einflussfaktoren der Feinstaubkonzentrationen aus Meteorologie, Verkehr, Architektur und zeitlichen Bedingungen zu beschreiben. Fahrradfahren repräsentiert diesbezüglich eine effiziente Vorgehensweise zur Charakterisierung individueller Feinstaubbelastungen mit der Möglichkeit einer hohen räumlich-zeitlichen Auflösung. Unter Beachtung der Hintergrundkonzentration können Aussagen zur relativen Schadstoffexposition und des einhergehenden Gesundheitsrisikos mit Erkenntnissen zugunsten einer umweltverträglichen innerstädtischen Verkehrsplanung getroffen werden.
... To prevent that physically separated pathways can be provided for pedestrians and cyclists. Preferably, these pathways should be away from motorized traffic or with a green barrier, to ensure their safety and lesser exposure to vehicular emissions (MacNaughton et al., 2014;Gallagher et al., 2015). In the current study, the modal share of NMT is 7.65%, the establishment of segregated pathways for cyclists is expected to lead to a higher modal share of non-motorized transportation, which would, in turn, contribute to reducing air pollution exposure. ...
... Sidewalks and bicycle lanes are places where passersby are most vulnerable to pollutants By improving the facilities of sidewalks and bicycle lanes, planning bicycle lanes in relatively quiet areas with a good environment, and isolating motor lanes from other roads by vegetation, pedestrians' exposure to pollutants can be reduced [139,140] Reduce the emission of traffic pollutants Exhaust from public transportation and private cars is the main source of pollutants in street canyons ...
Article
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The air quality in a street canyon seriously affects the exposure level of pollutants for pedestrians and is directly related to the indoor air quality (IAQ) of surrounding buildings. In order to improve the street canyon environment, it is necessary to clarify the distribution and dispersion characteristics of pollutants. Through field tests, wind tunnel experiments, and numerical simulation, the current research studied the nature of pollutants in street canyons and provided some improvement measures. This paper comprehensively introduces the characteristics of pollutants in street canyons and reviews past studies on the following parts: (a) the dispersion principle and main impact factors of pollutants in street canyons, (b) the spatial and temporal distribution of pollutants in street canyons, (c) the relationship between pollutants in street canyons and indoor air quality, and (d) improvement measures of the street canyon environment. The dispersion of pollutants is dominated by the air exchange between the street canyon and the upper atmosphere, which is strengthened when the wind speed is high or when the temperature in the street canyon is obviously higher than the surrounding area. The heat island effect is beneficial for pollutant dispersion, while the inversion layer has a negative influence. Dense buildings mean lower pollutant diffusion capacity, which causes pollutants to easily gather. Pollutants tend to accumulate on the leeward side of buildings. The concentration of pollutants decreases with the increase of height and drops to the background level at a height of several hundred meters. The temporal distribution of pollutants in street canyons varies in diurnal, weekly, and annual periods, and the concentration peaks in the winter morning and summer evening. Besides, pollutants in street canyons have a significant influence on IAQ. To improve the street canyon environment, green belts and other facilities should be reasonably set up in the streets. Future research should pay attention to comprehensive test data, solving disagreement conclusions, and quantitative evaluation of the various impact factors on pollutants, etc.
... Transport infrastructures, such as bicycle lanes and pedestrian corridors that encourage active transportation, are prime locations to plant trees. As well as helping to cool the air by providing shade, planting trees is an effective way to encourage physical activity, making these areas welcoming and attractive for people, and reducing cyclist and pedestrian exposure to pollution (MacNaughton et al., 2014;Lusk et al., 2018). Transportation corridors with both bicycle and pedestrian infrastructures have the highest potential for active transportation and hence deserve a high priority score (5), whereas roads with infrastructures for only cyclists or pedestrians received a lower priority score (3; medium potential, medium priority). ...
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As the climate continues to warm and the world becomes more urbanized, our reliance on trees and the benefits they provide is rapidly increasing. Many cities worldwide are planting trees to offset rising temperatures, trap pollutants, and enhance environmental and human health and well-being. To maximize the benefits of planting trees and avoid further increasing social inequities, a city needs to prioritize where to establish trees by first identifying those areas of greatest need. This work aims to demonstrate a spatially explicit approach for cities to determine these priority locations to achieve the greatest returns on specific benefits. Criteria for prioritization were developed in tandem with the City of Joliette, Canada, and based on nine indicators: surface temperature, tree density, vegetation cover, resilience, tree size and age, presence of species at risk, land use type, socioeconomic deprivation, and potential for active transportation. The City’s preferences were taken into account when assigning different weights to each indicator. The resulting tree planting priority maps can be used to target street tree plantings to locations where trees are needed most. This approach can be readily applied to other cities as these criteria can be adjusted to accommodate specific tree canopy goals and planning constraints. As cities are looking to expand tree canopy, we hope this work will assist in sustaining and growing their urban forest, enabling it to be more resilient and to keep providing multiple and sustained benefits where they are needed the most.
... Possible solutions might include the reduction of polluting traffic and/or the construction of separate cycle infrastructure. This latter allows cyclists to move further away from the polluting traffic (Macnaughton et al., 2014;Hatzopoulou et al., 2013). ...
Article
Background Differences in physical effort between cycling for transportation on an electric-assisted cycle (EAC) and a conventional cycle (CC) were previously studied. The effect of cycle type on respiratory ventilation and inhaled air pollution dose remains unclear. Objective The first aim was to predict respiratory ventilation while cycling on a conventional and electric-assisted cycle taking into account personal and route characteristics. The second aim was to predict the dose of inhaled pollutants while cycling on a conventional and electric-assisted cycle using the same independent variables. Methods Nineteen participants performed a maximal exercise test (lab test) and four cycling trips (field test): flat with CC and EAC, and hilly with CC and EAC. During each trip, heart rate, respiratory ventilation, oxygen uptake, and carbon dioxide production were measured continuously with a portable metabolic system. Cycling time, speed and distance as well as GPS coordinates were also recorded continuously. The ATMO-Street air pollution model was used to estimate black carbon (BC), nitrogen dioxide (NO2), particulate matter (PM2.5 and PM10) inhaled doses post hoc. Factors impacting respiratory ventilation and the dose of inhaled pollutants were estimated through linear mixed modelling including laboratory and field measurements. Results Mean respiratory ventilation was predicted based on sex (-7.78 L/min for women), cycle type (-17.61 L/min for EAC), height gain (+0.07 L/min) and speed (+1.30 L/min). Inhaled dose of pollutants both for BC dose/km and BC dose/min was primarily predicted by cycle type (-31.62% and -34.68% for EAC compared to CC, respectively). Results were similar for the other pollutants. Conclusions Cycle type, sex, speed and route topography contribute to the respiratory ventilation and the use of an EAC reduces the dose of inhaled pollutants by 33% compared to the CC. Future projects could develop an app that predicts the cleanest route in real-time based on physical effort and ambient air pollution to increase the health benefits of cycling.
... Cyclists can minimize their exposure to traffic-related air pollution (TRAP) for the duration of their shuttle by way of the use of bike paths preferentially over bike lanes regardless of the potential for improvement of traffic along these routes. Based on these study outcomes and the connection to the safety of bicycle users, planners have to encourage the improvement of bike pathways instead of bike lanes whenever feasible and must design bike pathways with vegetation between the cyclists and another vehicle [6]. ...
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The government should provide paths for pedestrians and cyclists base on Indonesia Government Regulation No. 22 of 2009. Kampung Inggris located in Pare District is a destination for local tourists to learn English. Tourists and residents in Pare sub-district use bicycles for their daily mobility. Currently, there is a mix of traffic in the Pare Central Business Districts (CBD), this is due to the unavailability of bicycle lanes in that area. The purpose of this research is to determine a bicycle lane to improve cyclist safety and improve air quality in the Pare CBD. The analytical method used in this research is stochastic traffic assignment to assign the bicycle route by using the Origin-Destination of the cyclist. The results showed the origin-destination movement for bicycle users in Pare District is mostly directed to Tulungrejo, Pare, Tretek. There are three alternative routes based on the results of the analysis which will serve as a typical bicycle route in the Pare CBD. There are several facilities to support typical bicycle lanes such as markers, traffic signs, and bicycle parking which must be prepared and equipped to support typical bicycle lane planning facilities in the Pare CBD.
... In this regard, the emergence of bike-sharing is closely related to its social and environmental benefits (Qiu & He, 2018) and is a good option for solving environmental problems related to the use of automobiles in major European cities (Zuurbier, Willems, Schaap, Van der Zee, & Hoek, 2019). These bikes can reduce the emission of hazardous particles and gaseous pollutants (MacNaughton, Melly, Vallarino, Adamkiewicz, & Spengler, 2014), and also reduce traffic congestion (Legros, 2019) and reduce noise pollution (Caulfield, O'Mahony, Brazil, & Weldon, 2017).Therefore, the present study seeks to provide valuable results in this regard by examining the benefits of using SB services in comparison with public transport (bus and taxi) during the outbreak of epidemic diseases. Thus, it is imperative to conduct this study in terms of the conditions under review and the current environment in countries affected by coronavirus epidemic, especially in Iran, which has been one of the high-risk countries for this epidemic. ...
Article
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In addition to the environmental problems that have plagued human life in recent decades, the outbreak of the coronavirus epidemic has endangered people’s health and adversely affected their lives in other ways. Therefore, the present study aimed to investigate the advantage of using shared bicycles (SB) during the outbreak of epidemics. For this purpose, 310 male subscribers of an SB system were examined. The research tool was a questionnaire taken from studies. The results showed that the environmental and health advantages were favourable, but the place advantage indicated a relatively unfavourable situation. The results of the structural equation model also showed that the advantages of using an SB based on the highest impact are the motivational advantage, health advantage, environmental advantage, social advantage, financial advantage and place advantage. These results can provide useful solutions for governments to reduce environmental risks and maintain health and physical activity during epidemics.
... In this regard, the emergence of bike-sharing is closely related to its social and environmental benefits (Qiu & He, 2018) and is a good option for solving environmental problems related to the use of automobiles in major European cities (Zuurbier, Willems, Schaap, Van der Zee, & Hoek, 2019). These bikes can reduce the emission of hazardous particles and gaseous pollutants (MacNaughton, Melly, Vallarino, Adamkiewicz, & Spengler, 2014), and also reduce traffic congestion (Legros, 2019) and reduce noise pollution (Caulfield, O'Mahony, Brazil, & Weldon, 2017).Therefore, the present study seeks to provide valuable results in this regard by examining the benefits of using SB services in comparison with public transport (bus and taxi) during the outbreak of epidemic diseases. Thus, it is imperative to conduct this study in terms of the conditions under review and the current environment in countries affected by coronavirus epidemic, especially in Iran, which has been one of the high-risk countries for this epidemic. ...
Preprint
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In addition to the environmental problems that have plagued human life in recent decades, the outbreak of the coronavirus epidemic has endangered people's health and adversely affected their lives in other ways. Therefore, the present study aimed to investigate the advantage of using shared bicycles (SB) during the outbreak of epidemics. For this purpose, 310 male subscribers of an SB system were examined. The research tool was a questionnaire taken from studies. The results showed that the environmental and health advantages were favourable, but the place advantage indicated a relatively unfavourable situation. The results of the structural equation model also showed that the advantages of using an SB based on the highest impact are the motivational advantage, health advantage, environmental advantage, social advantage, financial advantage and place advantage. These results can provide useful solutions for governments to reduce environmental risks and maintain health and physical activity during epidemics.
... Studies published since Bigazzi and Figliozzi (2014) review are mostly in line with these findings (e.g. Good et al. 2015;MacNaughton et al's 2014). Further studies have modelled, instead of measured, exposure contrasts in different routes: Hertel et al. (2008) found 10 to 30% higher exposures in shortest versus less trafficked streets (NO x , NO 2 , CO, PM 10 , PM 2.5 ); Hatzopoulou et al. (2013) estimated a 5% lower NO 2 concentration on lowest exposure route vs shortest route; and Li et al. (2017) estimated a 50% lower PM 2.5 exposure in the cleanest vs shortest cycling path. ...
Article
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Background Exposure to air pollution and physical inactivity are both significant risk factors for non-communicable diseases (NCDs). These risk factors are also linked so that the change in exposure in one will impact risks and benefits of the other. These links are well captured in the active transport (walking, cycling) health impact models, in which the increases in active transport leading to increased inhaled dose of air pollution. However, these links are more complex and go beyond the active transport research field. Hence, in this study, we aimed to summarize the empirical evidence on the links between air pollution and physical activity, and their combined effect on individual and population health. Objectives and methods We conducted a non-systematic mapping review of empirical and modelling evidence of the possible links between exposure to air pollution and physical activity published until Autumn 2019. We reviewed empirical evidence for the (i) impact of exposure to air pollution on physical activity behaviour, (ii) exposure to air pollution while engaged in physical activity and (iii) the short-term and (iv) long-term health effects of air pollution exposure on people engaged in physical activity. In addition, we reviewed (v) public health modelling studies that have quantified the combined effect of air pollution and physical activity. These broad research areas were identified through expert discussions, including two public events performed in health-related conferences. Results and discussion The current literature suggests that air pollution may decrease physical activity levels during high air pollution episodes or may prevent people from engaging in physical activity overall in highly polluted environments. Several studies have estimated fine particulate matter (PM2.5) exposure in active transport environment in Europe and North-America, but the concentration in other regions, places for physical activity and for other air pollutants are poorly understood. Observational epidemiological studies provide some evidence for a possible interaction between air pollution and physical activity for acute health outcomes, while results for long-term effects are mixed with several studies suggesting small diminishing health gains from physical activity due to exposure to air pollution for long-term outcomes. Public health modelling studies have estimated that in most situations benefits of physical activity outweigh the risks of air pollution, at least in the active transport environment. However, overall evidence on all examined links is weak for low- and middle-income countries, for sensitive subpopulations (children, elderly, pregnant women, people with pre-existing conditions), and for indoor air pollution. Conclusions Physical activity and air pollution are linked through multiple mechanisms, and these relations could have important implications for public health, especially in locations with high air pollution concentrations. Overall, this review calls for international collaboration between air pollution and physical activity research fields to strengthen the evidence base on the links between both and on how policy options could potentially reduce risks and maximise health benefits.
... Majority of other similar studies were conducted in large urban settings (Peters et al. 2014;Strak et al. 2010) where commuters were in close vicinity to vehicle emissions (Hatzopoulou et al. 2013a;Mueller et al. 2015). The general trends from previous research showed that cyclists were likely to receive higher exposures to traffic air pollution due to their close proximity to vehicle emissions and their increased minute exertion (MacNaughton et al. 2014;Panis et al. 2010;Ramos et al. 2016). Even though there are conflicting outcomes regarding vehicular pollution and its exposure, several epidemiological studies have already established the association between traffic emission and adverse health outcomes among cyclists, including respirable-related diseases (Barkovich et al. 2012;Nwokoro et al. 2012). ...
Article
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Cycling is often promoted as a means of reducing vehicular congestion, greenhouse gases, noise and air pollutant emissions in urban areas. It is also endorsed as a healthy means of transportation in terms of reducing the risk of developing a range of physical and psychological conditions. However, people might not be aware of the negative health impacts of cycling near heavy traffic. This study aimed to compare personal exposure with particulate air pollution among cyclists commuting in Perth, Western Australia. The study involved 122 number of cyclists riding bicycles in four different routes: two routes within community areas (Route 1 and Route 2) and two routes near freeways (Route 3 and Route 4). The participants were males and females aged between 20 and 55 years with the selection criteria including non-smokers who cycle at least 150 km/week—ideally along one of the four study routes. Personal exposure of respirable particulate air pollution during cycling at the high and low level of exertions (self-perceived) were assessed. Ambient concentrations of selected air pollutants were also measured at each cycling route. We found that Route 3 appeared to be the most polluted route and concentrations of nitrogen dioxide and sulphur dioxide exceeded the Australian standards. This study concluded that personal exposure to respirable particles was influenced by the speed, time of cycling and seasonal variation.
... The analysis of cyclist's exposure dose on individual routes shows much higher concentrations of PM 10 and PN 10 along the HT route than along the LT route. Similarly, MacNaughton et al. (2014) found that bike paths have lower concentrations of traffic-related pollutants than bike lanes along heavy traffic routes. Ham et al. (2017) found that average PM 2.5 concentrations were lowest for trips taken on a dedicated bike trail. ...
Article
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Cyclists’ exposure to air pollutants near roadways has been associated with numerous health effects. While the adverse health effects concerning aerosols have traditionally been assessed with data of particle mass concentrations, it appears that the number concentration is also another important indicator of toxicity. Thus, to holistically evaluate one’s exposure to aerosol particles, assessments should be based on mass concentrations and number concentrations. In order to assess individual cyclists’ exposure as they move through space and time, spatiotemporal high-resolution approaches are needed. Therefore, a mobile, fast-response monitoring platform was developed that uses a cargo bicycle as a base. Data of particle mass concentrations (PM1, PM2.5, PM10) and particle number concentrations (PN10) were collected along two different routes, one characterized by high-intensity vehicle traffic and one by low-intensity vehicle traffic. While high spatiotemporal heterogeneity was observed for all measured quantities, the PN10 concentrations fluctuated the most. High concentrations of PN10 could be clearly associated with vehicle traffic. For PM2.5, this relation was less pronounced. Mean particle concentrations of all measures were significantly higher along the high-traffic route. Comparing route exposures, the inhalation of PM2.5 was similar between both routes, whereas along the high-traffic route, cyclists were exposed to twice the particle number. We conclude that the cargo bike, featuring high-frequency mobile measurements, was useful to characterize the spatial distribution of mass concentrations and number concentrations across an urban environment. Overall, our results suggest that the choice of route is a key factor in reducing cyclists’ exposure to air pollution.
... A potential issue that receives less interest but requires further investigation is the impact of air pollution on bike sharing or using bikes in general. Many studies looked into exposure of bicyclists to air pollution [44][45][46]. On the other hand, only a handful studies reported that higher air pollution levels yield a significant negative impact on bike sharing [47] and that air quality improvement has a significant positive impact [48]. ...
Article
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Bike sharing is increasingly attracting more riders in cities around the world for its benefits regarding the urban environment and public health. The public bike sharing program of Seoul, South Korea, first launched in October 2015, is now widely spread around the city and serves more than 27,000 riders daily. However, concerns are being raised as rising air pollution levels in Seoul, represented by particulate matter (PM) levels, in recent years may negatively discourage citizens from using bike sharing. This study investigates the impact of PM10 and PM2.5 levels on bike sharing use in Seoul and seeks to identify any seasonal differences. A series of negative binomial regression models, which take into account control variables like weather conditions and calendar events, are adopted to empirically measure the impacts. Results show that the PM levels yield statistically significant negative impacts (p < 0.01) on bike sharing use throughout the year. The impacts are particularly stronger in winter and spring, when the PM levels are higher. Findings suggest that PM levels may operate as driving factors for bike sharing use in addition to meteorological conditions like temperature, humidity, and precipitation.
... By failing to account trips along such missing network features, disparities in exposure (however minor) can be introduced. For instance, since the presence of vegetation in urban greenspaces can act as a buffer to air pollution and, thus, lowering exposures to NO₂ air pollution in comparison to routes that journey around the outside boundary(MacNaughton et al., 2014). While this investigation would have benefited from a complete and fully representative highway network dataset, this does not suggest that the results produced are unreliable and do not provide a baseline of the changes in air pollution exposure between modes of transportation. ...
Thesis
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Air pollution exposure has been recognised as one of the leading concerns for adverse health impacts in urban environments. While active transportation has the potential to be a sustainable solution in addressing health concerns, individuals shifting to active transportation may be at risk of intensifying their spatial exposure. The investigation deals with Leicester, East Midlands, a city that has launched several active transportation initiatives to help meet national air quality targets. This dissertation undertakes a decision-support analysis of the spatial exposures to air pollution during active transportation, with a primary focus on walkability and cyclability. Exposure estimates for active and motorised transportation were generated through the employment of network analysis alongside ModelBuilder scripts within a GIS. The results demonstrate that active transportation is a viable option for reducing spatial exposures to air pollution. Commuters who make the shift from motorised to active transportation can reduce their mean exposure to NO₂ by 4.94 % during walking trips made within 2 km and by 8.43 % during cycling trips made within 5 km. In comparison to trips made by motorised transportation, commuters reduce their spatial exposures by travelling along dedicated walking and cycling routes that separate the commuter from direct vehicular emissions. Inconsistencies in exposure change during walking trips made to central Leicester can be explained by the limited accessibility and provision of lower exposure routes within urban hotspots. The contribution of this dissertation advances understandings current understandings in traffic-related exposures in the light of future health impact assessments.
... For example, Choi et al. (2018) found that PNC peaked within ±30 m from the intersections and Krecl et al. (2019b) reported a mean BC difference of 1.11 μg m −3 between two façades in a busy street canyon due to the influence of a bus stop. Both situations are associated with stopand-go driving patterns, such as vehicles idling at traffic lights (Kaur et al., 2006;Wang et al., 2008;MacNaughton et al., 2014) or buses stopping for dropping off and picking up passengers (Velasco and Tan, 2016;Krecl et al., 2019b). These traffic situations largely increase the exposure of cyclists and pedestrians, and even passengers and drivers on buses and in cars (through pollution infiltration into the cabin). ...
Article
We characterized the air pollution exposure of cyclists in the city center of Curitiba (Brazil) and then systematically analyzed the influence of several traffic management strategies (bus lanes, bicycle lanes, traffic calming area, traffic lights, and cleaner vehicle technologies) on the exposure. We focused on concentrations of particulates monitored on-board bicycles: PM2.5, black carbon mass (BC) and particle number concentration (PNC), and also reported on total volatile organic compound concentrations (TVOC). Overall, mean (± standard deviation) exposure was moderate compared to other cities around the world (BC: 6.98 ± 11.53 μg m⁻³, PM2.5: 33.22 ± 25.64 μg m⁻³, PNC: 3.93 × 10⁴ ± 4.17 × 10⁴ cm⁻³, TVOC: 361 ± 99 ppb). Concentrations were higher in the morning rush hour than in the afternoon traffic peak, and exhibited a large spatial variability. Bus stops and signalized traffic intersections emerged as hotspots when compared to the rest of the journey, increasing all particulate concentrations. Lower exposure was found on streets with low traffic (particularly, small number of heavy-duty vehicles) and within shallow canyon structure. The impact of traffic calming areas on cyclists' exposure is still inconclusive and further experimental and modelling studies are needed. Simple emission calculations based on traffic activity and real-world emission factors suggested that replacing the diesel bus fleet with hybrid electric buses might largely decrease (64%) the exposure to BC in the city center. Urban planners could use this valuable information to project new cycleways, which would lead to healthier active transportation. Synchronizing traffic signals might further reduce exposure at intersections.
... Over the last two decades, cyclists' individual exposure to air pollution-more specifically, their inhalation of pollutants [2]-has been, and continues to be, studied extensively (e.g., [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]). In contrast, during the same period, cyclists' noise exposure is, however, less often examined. ...
Article
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According to the World Health Organization, high levels of exposure to road traffic noise are associated with adverse health effects. Earlier studies suggest that cyclists are exposed to higher noise levels than motorists. Other studies have demonstrated that cyclists’ exposure to noise could vary significantly according to their routes. The aim of this study is to compare cyclists’ exposure to noise and their determinants in three cities. Three participants cycled equipped with noise dosimeters and GPS watches: 1823, 967, and 1362 km in Copenhagen, Paris, and Montreal, respectively. We fitted three generalized additive mixed model with an autoregressive term models to predict the cyclists’ exposure to noise according to the type of route and bicycle infrastructure after controlling for the day of the week, as well as spatial and temporal trends. The overall noise means were 73.4, 70.7, and 68.4 dB(A) in Paris, Montreal, and Copenhagen, respectively. The exposure to road traffic noise is strongly associated with the type of bicycle infrastructure taken by the cyclist; riding on a cycleway significantly decreases it, while riding in a shared lane has no impact. Our findings demonstrate that it is possible to achieve a substantial reduction in cyclists′ exposure by adopting new practices that include noise exposure in the planning of future cycling infrastructure.
... The rise of public-bicycle sharing is closely related to its own social and environmental benefits (Qiu and He, 2018). It has been considered a viable option in major European cities to solve environmental problems related to car driving (Zuurbier et al., 2019), it can reduce the emission of hazardous particulate and gaseous pollutants (MacNaughton et al., 2014), alleviate traffic congestion (Legros, 2019) and reduce noise pollution (Caulfield et al., 2017;Ji et al., 2014;Martens, 2007). As a sustainable means of transportation, it is popular in cities around the world (O'Brien et al., 2014). ...
Article
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Air pollution is a major global concern, leading to serious health problems and environmental damage. This article provides a comprehensive review of historical and current methods used to monitor and predict air quality. It emphasizes the ongoing need for better monitoring techniques. 47 studies are critically analyzed, and computational advancements in air quality monitoring are categorized into sensor‐based and image‐based techniques. This review reveals that sensor‐based algorithmic methods, representing 62% of the reviewed literature, are reliable but often lack flexibility and real‐time monitoring capabilities. On the other hand, image‐based techniques, while innovative, are limited by the size and diversity of datasets, primarily functioning only during daylight hours. To address these limitations, a hybrid approach that integrates both sensor and image‐based methods is proposed. This aims to enhance monitoring by allowing users to visualize pollution levels through an augmented reality layer. The proposed model seeks to provide mobile users with the ability to accurately monitor surrounding air quality by establishing a comprehensive image‐based dataset that includes various features not previously considered in existing datasets.
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If greenhouse gas emissions are not sharply reduced, air pollution, extreme weather events, and desertification in southern Spain will occur, along with many deaths, and collapses of the health system and the country’s main economic sectors, agriculture, and tourism. The European Union adopted a strategy in 2019 with a series of environmental policy initiatives to protect the population from climate change hazards as ‘the Green Deal’.This strategy provides funding opportunities for Granada, one of Spain's most polluted and climate change-vulnerable cities, to reduce its high emissions of harmful greenhouse gases from transport.A spacious, well-connected, and safe cycling infrastructure is needed. New on-road cycle lanes and cycle paths with planted barriers to the car lane should be constructed. An e-bike sharing system can also enable people with special needs to cycle in the hilly city and drive tourism. Extensive participation opportunities and assessments of disparate impacts on access and health outcomes of different population groups need to be used to ensure that existing inequalities are not exacerbated.
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The current need for the creation of cycleways in traditional cities often presents problems. Converting existing roads into cycleways frequently creates serious traffic issues without leading to the expected increase in bicycle use. In order to overcome some of these problems, this paper presents a composite methodology using GIS, topographic levelling and spatial analysis. Upon application of this methodology in a case study in the city of Patras, Greece, problems with the city’s existing, recently-constructed cycleway are identified. After applying topographical, qualitative and population criteria, an alternative network of cycleways is proposed. This proposed new network does not create traffic congestion, as the basic criterion for selecting roads is their low traffic load. At the same time, topographic leveling is employed to select routes with a very low gradient (<2%), which is a determining factor in making the network attractive to users. Using spatial analysis, the network is spread in order to serve all areas of the city, making it available to the vast majority of residents. Finally, the findings of a social research poll (through the use of a questionnaire) indicate that the creation of such a network could increase bicycle use by a factor of up to18, which would make bicycles the main mode of transport for 22% of residents.
Article
This paper presents a mixed-methods study of app-based motorcycle taxis in Thailand to explore the social dynamics of rideshare drivers and their exercised autonomy both through social pressure and a hostile work environment. As motorcycle taxis are open-air vehicles, drivers can be exposed to prolonged air pollution and other weather events, potentially impacting their health. In an initial quantitative study of server-side rideshare logs, we unexpectedly found that drivers do not exercise the autonomy provided by their rideshare platform to avoid air pollution events. This prompted a follow-on investigation through semi-structured interviews of both drivers and passengers in three provinces to explore why these drivers fail to experience the autonomy promised by gig-work in this context and elucidated further examples this lack of autonomy experienced by drivers. Our study sheds light on the social context that may constrain a driver's agency, including financial pressures, weather conditions, conflicts with local taxi organizations, and a false perception that drivers need to work around the ride assignment algorithm to avoid being blacklisted. We find that when leveraging app-based rideshare opportunities, drivers simultaneously perceive increased flexibility in their work hours and a lack of agency to prioritize their health and safety. We conclude with a discussion on potential interventions aimed at mitigating the forces preventing drivers from exercising their autonomy.
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Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Tyre abrasion (wear) contributes from one-third to half of microplastics unintentionally released into the environment. The major part ends up in the soil, a considerable amount is released into the aquatic environment, and a small percentage becomes airborne. Nevertheless, tyre abrasion contributes to 5–30% of road transport particulate matter (PM) emissions. This corresponds to approximately 5% of total ambient PM emissions. The particle mass size distribution peak at around 20 to 100 μm, with a second peak in the 2–10 μm range. A nucleation mode has been reported in some studies. The absolute abrasion levels depend on the tyre, vehicle, and road characteristics, but also on environmental conditions and driving style. Most tyre particle emission factors in the literature are based on data prior to the year 2000. We aggregated recent studies and found a mean abrasion of 110 mg/km per vehicle or 68 mg/km/t for passenger cars (based on approximately 300 measurements). Based on a limited number of studies, the PM10 emissions were 1.4–2.2 mg/km per tyre. On the other hand, the particle number emissions were in the order of 1010 #/km per tyre. The ratio of PM10 to total abrasion was found to be 2.5% on average. Finally, the ratio of PM2.5 to PM10 was calculated to be around 40%. Various mitigation measures for tyre particle pollution could be envisaged; the most direct is the limitation of the tyre abrasion rate, as proposed by the European Commission for the Euro 7 regulation. Other regulatory initiatives are also discussed.
Article
To assess the exposure of cyclists to particulate matter (PM) and black carbon (BC), real-time mobile monitoring with portable instruments was carried out on typical bike lanes in Xi'an, China. The inhalation dose as well as the deposition and distribution of different sizes of PM and BC in cyclists' respiratory systems, were quantified using a multiple-path particle dosimetry model (MPPD). A generalized linear regression model was fitted to explore the impact of different potentially influencing factors. The results of this case study in Xi'an showed that cyclists' exposure to PM2.5 (70.9 ± 30.0 μg m⁻³) and BC (7.5 ± 5.1 μg m⁻³) was marked by great temporal and spatial variability along the sampled urban routes, and their exposure hotspots generally consisted of intersections, temporary parking sites for vehicles, and diesel vehicles. Among the three types of bike lanes, cyclists were exposed to the lowest PM2.5 (62.9 ± 29.1 μg m⁻³) and BC (6.86 ± 4.0 μg m⁻³) concentrations on bike boulevards. The regression results revealed that certain factors, namely bike lanes, vegetation, and meteorological conditions, are correlated with cyclists' exposure to PM2.5. For their BC exposure, traffic volume was the predominant predictor. Concerning their regional deposition in the cyclists' respiratory system, PM2.5 was deposited to a greater extent in the head region (90%) than BC, the latter being deposited primarily in the pulmonary region (43%). This finding of greater BC deposition in the pulmonary region bolsters the need to incorporate BC into the current air-quality index of urban areas.
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Monitoring efficiently urban microclimates is necessary for rendering cities resilient against climate change impacts. Aiming to retrieve data of high spatial resolution, mobile monitoring techniques have been introduced and applied within various urban contexts around the globe. Mobile monitoring campaigns may indeed contribute toward a high-granularity evaluation of the intra-urban characteristics of each city. In addition, it can help exploit resiliency planning at different aggregation levels when implemented in conjunction with traditional monitoring systems, such as fixed stations and satellites. Under this scenario, this study presents for the first time a systematic and critical review of the recent and most comprehensive mobile monitoring systems, and the corresponding field campaigns and protocols followed. The reviewed monitoring systems are developed on either motorized (e.g. cars, vans) or non-motorized (e.g. bicycles, carts, humans) agents for measuring the main parameters regulating urban canopy layers with respect to the (i) hygrothermal environment, (ii) air quality, (iii) light pollution, (iv) noise pollution. Overall, 94 articles are analyzed for concluding to the current state of the art, the corresponding scientific gaps, and proposed future research paths. Most of the reported monitoring systems are developed to monitor only one environmental domain, while the lack of standardized monitoring protocols is found to be the biggest challenge that needs to be addressed for minimizing biases and rendering the outcomes of different studies comparable. Relevant technological advancements and human-centric frameworks are further discussed aiming to exploit mobile monitoring for establishing efficient decision-making and risk assessment within urban environments.
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A way to reduce carbon emissions in cities is through movement by bicycle or on foot. However, it sometimes means to pass through high-pollution zones and consequently breath low quality air. We then propose a green Intelligent Transportation System (ITS) for zero-emission mobility users, providing users with low-pollution routes to avoid the high-pollution zones. This proposal uses ITS to promote the use of alternative transportation to classical motor vehicles to reduce carbon emissions. This is based on Complex Event Processing (CEP) technology to gather and process real-time data, a Decision Support System designed as a Fuzzy Inference System (FIS) to make decisions about recommended transit zones, taking also into account the user experience level and specific weather data, and Colored Petri Nets (CPN) as a tool to compute the routes. This is therefore an all-in-one solution to provide green routes, with the benefits of each one of the technologies used.
Article
L’objectif de cet article est de modéliser l’exposition des cyclistes au bruit et au dioxyde d’azote (NO 2 ) à Lyon (France). Les données primaires (1 095 km), collectées à vélo en février 2019, permettent de construire trois modèles bayésiens (modèles généralisés additifs à effets mixtes avec un terme autorégressif) avec, comme variables dépendantes : le bruit (dB(A)), la concentration de NO 2 (μg/m 3 ) et l’inhalation de NO 2 (μg). Les résultats montrent que les expositions des cyclistes et l’inhalation de NO 2 varient significativement en fonction des types d’axes qu’ils empruntent. Par conséquent, ces deux nuisances urbaines devraient être prises en compte lors de la planification des voies cyclables.
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Air pollution exposure is highest during travel than any other daily activity. Though numerous research articles exist on different factors that affect on-road air pollution exposure, a systematic review of these factors and the influence of air pollution exposure on travel behaviour is absent. This work attempts to bridge this gap by identifying 110 studies using the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) methodology and presenting their comprehensive review. The findings show that (a) air pollution exposure is higher in open than close transport modes, (b) pedestrians and cyclists suffer the most due to higher respiration rates and proximity to the streets, (c) air pollution exposure causes both short and long-term changes in travel behaviour (d) despite the poor air quality, many developing nations lack adequate work on exposure. Finally, this work identifies the potential research gaps and provides insights into policymaking to reduce travellers' air pollution exposure.
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In this pilot study, low-cost air pollution sensor nodes were fitted in waste removal trucks, hospital vans and taxis to record drivers’ exposure to air pollution in Central London. Particulate matter (PM 2.5 and PM 10 ), CO 2 , NO 2 , temperature and humidity were recorded in real-time with nodes containing low-cost sensors, an electrochemical gas sensor for NO 2 , an optical particle counter for PM 2.5 and PM 10 and a non-dispersive infrared (NDIR) sensor for CO 2 , temperature and relative humidity. An intervention using a pollution filter to trap PM and NO 2 was also evaluated. The measurements were compared with urban background and roadside monitoring stations at Honor Oak Park and Marylebone Road, respectively. The vehicle records show PM and NO 2 concentrations similar to Marylebone Road and a higher NO 2 -to-PM ratio than at Honor Oak Park. Drivers are exposed to elevated pollution levels relative to Honor Oak Park: 1.72 μ g m − 3 , 1.92 μ g m − 3 and 58.38 ppb for PM 2.5 , PM 10 , and NO 2 , respectively. The CO 2 levels ranged from 410 to over 4000 ppm. There is a significant difference in average concentrations of PM 2.5 and PM 10 between the vehicle types and a non-significant difference in the average concentrations measured with and without the pollution filter within the sectors. In conclusion, drivers face elevated air pollution exposure as part of their jobs.
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This paper is an empirical review of the development of two-wheeled transport, comprising human-powered bicycles, E-bikes, and motorbikes in China from 1985 to 2019, aimed at investigating the development of two-wheeled transport in China. A series of demand-side factors (e.g., rapid urbanization) and supply-side factors (e.g., obsolete infrastructure) are explored. The mode share of human-powered bicycles decreased steadily until 2016, the year dockless bikeshare (DBS) emerged. During that time, government policy changed from “encouraged”, “discouraged”, “converted and re-recognized” to “encouraged again” due to sophisticated socio-economic change. E-bikes and motorbikes witnessed an independent growth trend and changing political attitude from that of human-powered bicycles. The future of the human-powered bicycle transport mode in China is promising, due to favorable government policies and the growing demand from users for a flexible mode of transport to serve short-middle distance and last-mile trips. E-bikes have an uncertain future since local policies differ, and safety issues are yet to be addressed. Motorbikes, due to their negative safety and environmental considerations, have been increasingly replaced by automobiles, and this makes their future position marginal.
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Bicycling as a mode of transportation is increasingly seen as a healthy alternative to motorized transportation modes. However, in congested urban areas, the health benefits of bicycling can be diminished by the negative health effects associated with inhalation of particulate matter. Particles of small size (ultrafine particles <0.1 mu m) are the most harmful, even during short-duration exposure. Because vehicular exhaust is the major source of ultrafine particles, the impact of traffic levels and bicycle lane characteristics on exposure of bicyclists was studied. Ultrafine particle exposure concentrations were compared in two settings: (a) a traditional bicycle lane adjacent to the vehicular traffic lanes and (b) a cycle track design with a parking lane separating bicyclists from vehicular traffic lanes. Traffic measurements were made alongside air quality measurements. The cycle track design mitigated ultrafine particle exposure concentrations for cyclists. Results showed statistically significant differences in terms of exposure levels for the two bike facilities, as well as correlations between traffic levels and exposure level differences. Results also suggested that ultrafine particle levels and spatial distribution were sensitive to proximity to signalized intersections. Findings of this research indicated that, in high traffic areas, bicycle facility design had the potential to lower air pollution exposure levels of bicyclists.
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Current day concentrations of ambient air pollution have been associated with a range of adverse health effects, particularly mortality and morbidity due to cardiovascular and respiratory diseases. In this review, we summarize the evidence from epidemiological studies on long-term exposure to fine and coarse particles, nitrogen dioxide (NO2) and elemental carbon on mortality from all-causes, cardiovascular disease and respiratory disease. We also summarize the findings on potentially susceptible subgroups across studies. We identified studies through a search in the databases Medline and Scopus and previous reviews until January 2013 and performed a meta-analysis if more than five studies were available for the same exposure metric.
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Real-time aerosol black carbon (BC) data, presented at time resolutions on the order of seconds to minutes, is desirable in field and source characterization studies measuring rapidly varying concentrations of BC. The Optimized Noise-reduction Averaging (ONA) algorithm has been developed to post-process data from the Aethalometer, one of the widely used real-time BC instruments. The ONA program conducts adaptive time-averaging of the BC data, with the incremental light attenuation (∆ATN) through the instrument's internal filter determining the time window of averaging. Analysis of instrument noise and the algorithm performance was conducted using Aethalometer 1-second data from a soot generation experiment, where input BC concentrations were maintained constant and an optimal ∆ATN min value was defined. The ONA procedure was applied to four additional data sets (1 s to 5 min data), including cookstove emissions tests, mobile monitoring, continuous near-road measurements, and indoor air sampling. For these data, the algorithm reduces the occurrence of negative values to virtually zero while preserving the significant dynamic trends in the time series.
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Urban particulate air pollution is a serious health issue. Trees within cities can remove fine particles from the atmosphere and consequently improve air quality and human health. Tree effects on PM2.5 concentrations and human health are modeled for 10 U.S. cities. The total amount of PM2.5 removed annually by trees varied from 4.7 tonnes in Syracuse to 64.5 tonnes in Atlanta, with annual values varying from 1.1millioninSyracuseto1.1 million in Syracuse to 60.1 million in New York City. Most of these values were from the effects of reducing human mortality. Mortality reductions were typically around 1 person yr(-1) per city, but were as high as 7.6 people yr(-1) in New York City. Average annual percent air quality improvement ranged between 0.05% in San Francisco and 0.24% in Atlanta. Understanding the impact of urban trees on air quality can lead to improved urban forest management strategies to sustain human health in cities.
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Background A travel mode shift to active transportation such as bicycling would help reduce traffic volume and related air pollution emissions as well as promote increased physical activity level. Cyclists, however, are at risk for exposure to vehicle-related air pollutants due to their proximity to vehicle traffic and elevated respiratory rates. To promote safe bicycle commuting, the City of Berkeley, California, has designated a network of residential streets as “Bicycle Boulevards.” We hypothesized that cyclist exposure to air pollution would be lower on these Bicycle Boulevards when compared to busier roads and this elevated exposure may result in reduced lung function. Methods We recruited 15 healthy adults to cycle on two routes – a low-traffic Bicycle Boulevard route and a high-traffic route. Each participant cycled on the low-traffic route once and the high-traffic route once. We mounted pollutant monitors and a global positioning system (GPS) on the bicycles. The monitors were all synced to GPS time so pollutant measurements could be spatially plotted. We measured lung function using spirometry before and after each bike ride. Results We found that fine and ultrafine particulate matter, carbon monoxide, and black carbon were all elevated on the high-traffic route compared to the low-traffic route. There were no corresponding changes in the lung function of healthy non-asthmatic study subjects. We also found that wind-speed affected pollution concentrations. Conclusions These results suggest that by selecting low-traffic Bicycle Boulevards instead of heavily trafficked roads, cyclists can reduce their exposure to vehicle-related air pollution. The lung function results indicate that elevated pollutant exposure may not have acute negative effects on healthy cyclists, but further research is necessary to determine long-term effects on a more diverse population. This study and broader field of research have the potential to encourage policy-makers and city planners to expand infrastructure to promote safe and healthy bicycle commuting.
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Cyclists may experience increased exposure to traffic-related air pollution owing to increased minute ventilation and close proximity to vehicle emissions. The aims of this study were to characterize personal exposures to air pollution among urban cyclists and to identify potential determinants of exposure including the type of cycling lane (separated vs on-road), traffic counts, and meteorological factors. In total, personal air pollution exposure data were collected over 64 cycling routes during morning and evening commutes in Montreal, Canada, over 32 days during the summer of 2011. Measured pollutants included ultrafine particles (UFPs), fine particles (PM(2.5)), black carbon (BC), and carbon monoxide (CO). Counts of diesel vehicles were important predictors of personal exposures to BC, with each 10 vehicle/h increase associated with a 15.0% (95% confidence interval (CI): 5.7%, 24.0%) increase in exposure. Use of separated cycling lanes had less impact on personal exposures with a 12% (95% CI: -43%, 14%) decrease observed for BC and smaller decreases observed for UFPs (mean: -1.3%, 95% CI: -20%, 17%) and CO (mean: -5.6%, 95% CI: -17%, 4%) after adjusting for meteorological factors and traffic counts. On average, PM(2.5) exposure increased 7.8% (95% CI: -17%, 35%) with separate cycling lane use, but this estimate was imprecise and not statistically significant. In general, our findings suggest that diesel vehicle traffic is an important contributor to personal BC exposures and that separate cycling lanes may have a modest impact on personal exposure to some air pollutants. Further evaluation is required, however, as the impact of separate cycling lanes and/or traffic counts on personal exposures may vary between regions.Journal of Exposure Science and Environmental Epidemiology advance online publication, 22 August 2012; doi:10.1038/jes.2012.85.
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Recent studies have suggested that exposures during traffic participation may be associated with adverse health effects. Traffic participation involves relatively short but high exposures. Potentially relevant exposures include ultrafine particles, fine particles (PM2.5) and noise.Simultaneously, detailed real time exposure of particle number concentration (PNC), PM2.5 and noise has been measured while driving and cycling 12 predefined routes of approximately 10–20 min duration. Sampling took place in eleven medium-sized Dutch cities on eleven weekdays in August till October 2006. To investigate variability in cyclists exposure, we systematically collected information on meteorology, GPS coordinates, type of road, traffic intensity, passing vehicles and mopeds while cycling.The overall mean PNC of car drivers was 5% higher than the mean PNC of cyclists. The overall mean concentration of PM2.5 in the car was 11% higher than during cycling. Slightly higher 1-min peak concentrations were measured in the car (PNC 14%; PM2.5 29% for 95-percentiles). Shorter duration peaks of PNC were higher during cycling (43% for 99-percentile of 1-s averages). Peaks in PNC typically last for less than 10 s. A large variability of exposure was found within and between routes. Factors that significantly predicted PNC variability during cycling were: passing vehicles (mopeds, cars), waiting for traffic lights, passing different types of (large) intersections and bicycle lanes and bike paths close to motorized traffic. No relation was found between PM2.5 and those predictor variables. The correlation between PNC and noise was moderate (median 0.34). PM2.5 had very low correlations with PNC and noise.PNC and PM2.5 exposure of car drivers was slightly higher than that of cyclists. PNC was largely uncorrelated with PM2.5 and reflected local traffic variables more than PM2.5. Different factors were associated with high PNC and high noise exposures.
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Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM(10)) or ≤ 2.5 μm (PM(2.5))] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration. We evaluated the value of black carbon particles (BCP) as an additional indicator in air quality management. We performed a systematic review and meta-analysis of health effects of BCP compared with PM mass based on data from time-series studies and cohort studies that measured both exposures. We compared the potential health benefits of a hypothetical traffic abatement measure, using near-roadway concentration increments of BCP and PM(2.5) based on data from prior studies. Estimated health effects of a 1-μg/m3 increase in exposure were greater for BCP than for PM(10) or PM(2.5), but estimated effects of an interquartile range increase were similar. Two-pollutant models in time-series studies suggested that the effect of BCP was more robust than the effect of PM mass. The estimated increase in life expectancy associated with a hypothetical traffic abatement measure was four to nine times higher when expressed in BCP compared with an equivalent change in PM(2.5) mass. BCP is a valuable additional air quality indicator to evaluate the health risks of air quality dominated by primary combustion particles.
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Few studies have examined the acute health effects of air pollution exposures experienced while cycling in traffic. We conducted a crossover study to examine the relationship between traffic pollution and acute changes in heart rate variability. We also collected spirometry and exhaled nitric oxide measures. Forty-two healthy adults cycled for 1 hr on high- and low-traffic routes as well as indoors. Health measures were collected before cycling and 1-4 hr after the start of cycling. Ultrafine particles (UFPs; ≤ 0.1 μm in aerodynamic diameter), particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5), black carbon, and volatile organic compounds were measured along each cycling route, and ambient nitrogen dioxide (NO2) and ozone (O3) levels were recorded from a fixed-site monitor. Mixed-effects models were used to estimate associations between air pollutants and changes in health outcome measures relative to precycling baseline values. An interquartile range increase in UFP levels (18,200/cm3) was associated with a significant decrease in high-frequency power 4 hr after the start of cycling [β = -224 msec2; 95% confidence interval (CI), -386 to -63 msec2]. Ambient NO2 levels were inversely associated with the standard deviation of normal-to-normal (NN) intervals (β = -10 msec; 95% CI, -20 to -0.34 msec) and positively associated with the ratio of low-frequency to high-frequency power (β = 1.4; 95% CI, 0.35 to 2.5) 2 hr after the start of cycling. We also observed significant inverse associations between ambient O3 levels and the root mean square of successive differences in adjacent NN intervals 3 hr after the start of cycling. Short-term exposures to traffic pollution may contribute to altered autonomic modulation of the heart in the hours immediately after cycling.
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Commuters are exposed to high concentrations of air pollutants, but little quantitative information is currently available on differences in exposure between different modes of transport, routes, and fuel types. The aim of our study was to assess differences in commuters' exposure to traffic-related air pollution related to transport mode, route, and fuel type. We measured particle number counts (PNCs) and concentrations of PM2.5 (particulate matter <or= 2.5 microm in aerodynamic diameter), PM10, and soot between June 2007 and June 2008 on 47 weekdays, from 0800 to 1000 hours, in diesel and electric buses, gasoline- and diesel-fueled cars, and along two bicycle routes with different traffic intensities in Arnhem, the Netherlands. In addition, each-day measurements were taken at an urban background location. We found that median PNC exposures were highest in diesel buses (38,500 particles/cm3) and for cyclists along the high-traffic intensity route (46,600 particles/cm3) and lowest in electric buses (29,200 particles/cm3). Median PM10 exposure was highest from diesel buses (47 microg/m3) and lowest along the high- and low-traffic bicycle routes (39 and 37 microg/m3). The median soot exposure was highest in gasoline-fueled cars (9.0 x 10-5/m), diesel cars (7.9 x 10-5/m), and diesel buses (7.4 x 10-5/m) and lowest along the low-traffic bicycle route (4.9 x 10-5/m). Because the minute ventilation (volume of air per minute) of cyclists, which we estimated from measured heart rates, was twice the minute ventilation of car and bus passengers, we calculated that the inhaled air pollution doses were highest for cyclists. With the exception of PM10, we found that inhaled air pollution doses were lowest for electric bus passengers. Commuters' rush hour exposures were significantly influenced by mode of transport, route, and fuel type.
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Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists. We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights) or between intersections on "straightaways" (e.g. bike lanes or paths). To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls). The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways) suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths) was associated with the lowest risk. Evidence is beginning to accumulate that purpose-built bicycle-specific facilities reduce crashes and injuries among cyclists, providing the basis for initial transportation engineering guidelines for cyclist safety. Street lighting, paved surfaces, and low-angled grades are additional factors that appear to improve cyclist safety. Future research examining a greater variety of infrastructure would allow development of more detailed guidelines.
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Monitoring studies have shown that commuters are exposed to high air pollution concentrations, but there is limited evidence of associated health effects. We carried out a study to investigate the acute respiratory health effects of air pollution related to commuting by bicycle. Twelve healthy adults cycled a low- and a high-traffic intensity route during morning rush hour in Utrecht, The Netherlands. Exposure to traffic-related air pollution was characterised by measurements of PM(10), soot and particle number. Before, directly after and 6 h after cycling we measured lung function (FEV(1), FVC, PEF), exhaled NO (FE(NO)) and respiratory symptoms. The association between post- minus pre-exposure difference in health effects and exposure during cycling was evaluated with linear regression models. The average particle number concentration was 59% higher, while the average soot concentration was 39% higher on the high-traffic route than on the low-traffic route. There was no difference for PM(10). Contrary to our hypothesis, associations between air pollution during cycling and lung function changes immediately after cycling were mostly positive. Six hours after cycling, associations between air pollution exposure and health were mostly negative for lung function changes and positive for changes in exhaled NO, although non-significant. We found substantial differences in ultrafine particle number and soot exposure between two urban cycling routes. Exposure to ultrafine particles and soot during cycling was weakly associated with increased exhaled NO, indicative of airway inflammation, and decrements in lung function 6 h after exposure. A limitation of the study was the relatively small sample size.
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Exposure assessment studies in the developing world are important. Although recent years have seen an increasing number of traffic-related pollution exposure studies, exposure assessment data on this topic are still limited. Differences among measuring methods and a lack of strict quality control in carrying out exposure assessment make it difficult to generalize and compare findings between studies. In this article, exposure assessment studies carried out in the developing world on several traffic-related air pollutants are reviewed. These pollutants include particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO(2)), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). In addition, it discusses advantages and disadvantages of various monitoring methods (ambient fixed-site monitoring, microenvironment monitoring, and personal exposure assessment using portable samplers) for these pollutants in exposure assessment studies. Also included in this paper is a brief introduction of standards for these pollutants in ambient air or in occupational settings established by the United States Environmental Protection Agency (USEPA), the United States Occupational Safety and Health Administration (OSHA) and the World Health Organization (WHO). The review ends with a summary of the limitations and gaps in recent studies and suggestions for future research in the developing world.
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A proper selection of route through the urban area may significantly reduce the air pollution exposure. This is the main conclusion from the presented study. Air pollution exposure is determined for two selected cohorts along the route going from home to working place, and back from working place to home. Exposure is determined with a street pollution model for three scenarios: bicycling along the shortest possible route, bicycling along the low exposure route along less trafficked streets, and finally taking the shortest trip using public transport. Furthermore, calculations are performed for the cases the trip takes place inside as well as outside the traffic rush hours. The results show that the accumulated air pollution exposure for the low exposure route is between 10% and 30% lower for the primary pollutants (NO(x) and CO). However, the difference is insignificant and in some cases even negative for the secondary pollutants (NO(2) and PM(10)/PM(2.5)). Considering only the contribution from traffic in the travelled streets, the accumulated air pollution exposure is between 54% and 67% lower for the low exposure route. The bus is generally following highly trafficked streets, and the accumulated exposure along the bus route is therefore between 79% and 115% higher than the high exposure bicycle route (the short bicycle route). Travelling outside the rush hour time periods reduces the accumulated exposure between 10% and 30% for the primary pollutants, and between 5% and 20% for the secondary pollutants. The study indicates that a web based route planner for selecting the low exposure route through the city might be a good service for the public. In addition the public may be advised to travel outside rush hour time periods.
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Reducing exposure to atmospheric nanoparticles in urban areas is important for protecting public health. Developing new or improving the capabilities of existing dispersion models will help to design effective mitigation strategies for nanoparticle rich environments. The aims of this review are to summarise current practices of nanoparticle dispersion modelling at five local scales (i.e. vehicle wake, street canyons, neighbourhood, city and road tunnels), together with highlighting associated challenges, research gaps and priorities. The review begins with a synthesis of available information about the flow and mixing characteristics in urban environments which is followed by a brief discussion on dispersion modelling of nanoparticles. Further sections cover the effects of transformation processes in dispersion modelling of nanoparticles, and a critical discussion on associated structural and parametric uncertainties in modelling. The article concludes with a comprehensive summary of current knowledge
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The exposure of bus commuters and a cyclist to respirable particles in the city of Manchester has been evaluated, using personal sampling pumps installed in the cabs of the vehicles and carried by the cyclist. These have provided an estimate of the average exposure of commuters using bus services and cycling in a congested European city.
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We present initial results obtained from an optical absorption sensor for the monitoring of ambient atmospheric nitrogen dioxide concentrations (0-200 ppb). This sensor utilizes cavity attenuated phase shift spectroscopy, a technology related to cavity ringdown spectroscopy. A modulated broadband incoherent light source (a 430-nm LED) is coupled to an optically resonant cavity formed by two high-reflectivity mirrors. The presence of NO(2) in the cell causes a phase shift in the signal received by a photodetector that is proportional to the NO(2) concentration. The sensor, which employed a 0.5-m cell, was shown to have a sensitivity of 0.3 ppb in the photon (shot) noise limit. Improvements in the optical coupling of the LED to the resonant cavity would allow the sensor to reach this limit with integration times of 10 s or less (corresponding to a noise equivalent absorption coefficient of <1 x 10(-8) cm(-1) Hz(-1/2)). Over a 2-day-long period of ambient atmospheric monitoring, a comparison of the sensor with an extremely accurate and precise tunable diode laser-based absorption spectrometer showed that the CAPS-based instrument was able to reliably and quantitatively measure both large and small fluctuations in the ambient nitrogen dioxide concentration.
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Evidence for a causal relationship between traffic-related air pollution and asthma has not been consistent across studies, and comparisons among studies have been difficult because of the use of different indicators of exposure. We examined the association between traffic-related pollution and childhood asthma in 208 children from 10 southern California communities using multiple indicators of exposure. Study subjects were randomly selected from participants in the Children's Health Study. Outdoor nitrogen dioxide (NO2) was measured in summer and winter outside the home of each child. We also determined residential distance to the nearest freeway, traffic volumes on roadways within 150 meters, and model-based estimates of pollution from nearby roadways. Lifetime history of doctor-diagnosed asthma was associated with outdoor NO2; the odds ratio (OR) was 1.83 (95% confidence interval=1.04-3.22) per increase of 1 interquartile range (IQR=5.7 ppb) in exposure. We also observed increased asthma associated with closer residential distance to a freeway (1.89 per IQR; 1.19-3.02) and with model-based estimates of outdoor pollution from a freeway (2.22 per IQR; 1.36-3.63). These 2 indicators of freeway exposure and measured NO2 concentrations were also associated with wheezing and use of asthma medication. Asthma was not associated with traffic volumes on roadways within 150 meters of homes or with model-based estimates of pollution from nonfreeway roads. These results indicate that respiratory health in children is adversely affected by local exposures to outdoor NO2 or other freeway-related pollutants.
Transportation fact book and neighborhood profiles Accessed from City of Boston Website http://www.cityofboston.gov/bikes/statistics.asp, 2010. Federal Highway Adminstration. Bicycle and pedestrian provisions of the federal-aid pro-gram
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  • Boston
City of Boston. Transportation fact book and neighborhood profiles. Accessed from City of Boston Website, 2012. http://www.cityofboston.gov/bikes/statistics.asp, 2010. Federal Highway Adminstration. Bicycle and pedestrian provisions of the federal-aid pro-gram. http://www.fhwa.dot.gov/environment/bicycle_pedestrian/overview/bp-broch.cfm#funding, 2012.
Transportation fact book and neighborhood profiles Accessed from City of Boston Website
  • City
  • Boston
City of Boston. Transportation fact book and neighborhood profiles. Accessed from City of Boston Website, 2012. http://www.cityofboston.gov/bikes/statistics.asp, 2010.