Fine particle concentrations in buses and taxis in Florence, Italy (original) (raw)
Related papers
Risk Analysis, 2005
Fine particle (PM 2.5 ) emissions from traffic have been associated with premature mortality. The current work compares PM 2.5 induced mortality in alternative public bus-transportation strategies as being considered by the Helsinki Metropolitan Area Council, Finland. The current bus fleet and transportation volume is compared to four alternative hypothetical bus fleet strategies for the year 2020: (i) the current bus fleet for 2020 traffic volume; (ii) modern diesel buses without particle traps, (iii) diesel buses with particle traps, and (iv) buses using natural gas engines.
Atmospheric Environment, 2005
Fine particulate matter (PM 2.5 ) and particle number concentrations were monitored in the Helsinki subway system during a two-weeks' measurement campaign in March 2004. The PM 2.5 samples was analysed for elemental composition and carbon fraction. The average daytime PM 2.5 concentrations were 47 (74) and 60 (718) mg m À3 at the two underground subway stations and 19 (76) and 21 (74) mg m À3 at a ground level station and in subway cars, respectively. For the same measurement period, the corresponding PM 2.5 concentrations at the urban background and street canyon monitoring sites were 10 (77) and 17 (710) mg m À3 .
Fine particulate (PM2.5–PM1) at urban sites with different traffic exposure
Atmospheric Environment, 2005
Fine particulate concentration data resulting from several monitoring campaigns performed in the city of Milan at urban sites with different exposure to the emission sources are presented. Low volume PM2.5 and PM1 samplers are utilised together with a low volume optical analyser, enabling the intercomparison between the measurements obtained by the gravimetrical and the optical method. The concentration levels observed at the different sites are compared in order to point out intra-site seasonal differences and inter-site differences for corresponding seasons of the year. These different concentration levels are analysed and explained considering the exposure to the primary emissions and accounting for the role of meteorology. PM10, PM2.5 and PM1 are described in terms of the distribution of 1-h concentration data and their relative mass fractions are determined. In order to assess the significance of secondary sources of fine particulate, a PM2.5 high volume sampler is utilised for the collection of dust-loaded filters to be analysed for chemical characterisation. The composition of PM2.5 emission from traffic is investigated by analysing 24h samples from an urban tunnel site (TU): data on carbonaceous species, organic carbon (OC) and elemental carbon (EC), are obtained and the ratio between these species is evaluated for real traffic emissions. Secondary organic aerosol (SOA) contribution to PM2.5 mass in ambient air is assessed by means of the primary OC/EC ratio approach, based on chemical data of the filters from the TU. Organic and inorganic secondary production in the outdoor atmosphere is contributing for about 75% of PM2.5 mass in winter and 40% in summer: as a consequence, effective long-term actions, still controlling the emissions of primary pollutants too, are required for air quality standards attainment and the potentiality of short-term interventions, as traffic restriction, appears quite limited. r
Commuter exposure to fine and ultrafine particulate matter in Vienna
Wiener klinische Wochenschrift
Mass concentrations PM10, PM2.5, PM1, particle number concentrations of ultrafine particles and lung deposited surface area were measured during commutes with a subway, tram, bus, car and bicycle in Vienna for the first time. Obtained data were examined for significant differences in personal exposure when using various transport modalities along similar routes. Mean PM2.5 and PM1 mass concentrations were significantly higher in the subway when compared to buses. Mean PM10, PM2.5 and PM1 mass concentrations were significantly higher in the subway when compared to cars using low ventilation settings. Particle number concentrations of ultrafine particles were significantly higher in trams when compared to the subway and lung deposited surface area was significantly greater on bicycles when compared to the subway. After adjusting for different vehicle speeds, exposure to PM10, PM2.5 and PM1 along the same route length was significantly higher in the subway when compared to cars while exposure to ultrafine particles and partly also lung deposited surface area was significantly higher in bus, tram and on bicycle when compared to the subway. Car and bus passengers could be better isolated from ambient fine particulate matter than passengers in the subway, where a lot of ventilation occurs through open windows and larger doors. Tram passengers and cyclists might be exposed to increased amounts of ultrafine particles and larger lung deposited surface area due to a closer proximity to road traffic. Comparing cumulative exposure along the same route length leads to different results and favors faster traffic modes, such as the subway.
Variability of Personal Exposure to Fine Particulates for Urban Commuters Inside Automobiles
Transportation Research Record, 2006
Over the last decade, a growing body of evidence has emerged to suggest a causal link between short-duration exposure to elevated levels of fine airborne particulate matter and adverse health consequences. It is believed much of this 'peak' exposure occurs in transport microenvironments both because of the higher levels of fine particulates associated with road traffic, primarily from diesel exhaust emissions, and the fact people spend a significant amount of time traveling (for instance, 80 minutes/day for residents of Sydney). While previous studies have suggested substantial differences in exposure rates due to factors such as choice of mode, route, in-vehicle conditions, and meteorological factors, current measurement techniques have restricted insights to fairly coarse sampling intervals (e.g., every half hour, every trip). As a consequence, little tangible evidence is available on how pollution varies over a trip and most critically about the location, duration, and magnitude of peak excursions within trips. The current paper reports on a study in which the capabilities of Global Positioning Systems (GPS) and real-time particle monitors are combined to address this problem for an urban commute trip in Sydney. This ability to precisely spatially reference pollution data and in particular identify 'hotspots' holds considerable promise for both our understanding and reporting of such data in the future.
Journal of Exposure Science and Environmental Epidemiology, 2007
Personal exposure to PM 2.5 and PM 1 , together with indoor and residential outdoor levels, was measured in the general adult population (30 subjects, 23-51 years of age) of Gothenburg, Sweden. Simultaneously, urban background concentrations of PM 2.5 were monitored with an EPA WINS impactor. The 24-h samples were gravimetrically analyzed for mass concentration and black smoke (BS) using a smokestain reflectometer. Median levels of PM 2.5 were 8.4 mg/m 3 (personal), 8.6 mg/m 3 (indoor), 6.4 mg/m 3 (residential outdoor), and 5.6 mg/m 3 (urban background). Personal exposure to PM 1 was 5.4 mg/m 3 , while PM 1 indoor and outdoor levels were 6.2 and 5.2 mg/m 3 , respectively. In non-smokers, personal exposure to PM 2.5 was significantly higher than were residential outdoor levels. BS absorption coefficients were fairly similar for all microenvironments (0.4-0.5 10 À5 m À1 ). Personal exposure to particulate matter (PM) and BS was well correlated with indoor levels, and there was an acceptable agreement between personal exposure and urban background concentrations for PM 2.5 and BS 2.5 (r s ¼ 0.61 and 0.65, respectively). PM 1 made up a considerable amount (70-80%) of PM 2.5 in all microenvironments. Levels of BS were higher outdoors than indoors and higher during the fall compared with spring. The correlations between particle mass and BS for both PM 2.5 vs. BS 2.5 and PM 1 versus BS 1 were weak for all microenvironments including personal exposure. The urban background station provided a good estimate of residential outdoor levels of PM 2.5 and BS 2.5 within the city (r s ¼ 0.90 and 0.77, respectively). Outdoor levels were considerably affected by long-range transported air pollution, which was not found for personal exposure or indoor levels. The within-individual (day-today) variability dominated for personal exposure to both PM 2.5 and BS 2.5 in non-smokers.
Exposure to Aerosols Particles on an Urban Road
Journal of Ecological Engineering
Traffic-related emissions, apart from emissions from fuel combustion for heating purposes, significantly deteriorate air quality in cities. The above mainly concerns areas located close to busy traffic routes. According to epidemiological studies, traffic-related emissions have an adverse health effect. This specifically affects commuters (drivers and car passengers) as well as pedestrians. The aim of this study was to determine the variations of particle number and mass concentrations along a busy road in Lublin, Poland and their impact on the particle exposure for commuters and pedestrians. On-route and fixed-site measurements were performed in the summer (June) with a focus on peak and off-peak traffic hours and road sections with low and high traffic intensity. During peak hours, the average number concentration of ultrafine particles (PN 0.1) in the road section near 4-way traffic intersections (TIs) was about 2 times higher than during off-peak hours. The average mass concentration of fine particles (PM 2.5) was also approximately twice as high than in off-peak hours. Similar relations were found for other measured aerosol particles as well as with respect to particle exposure. The obtained results indicate the need for further extended research on traffic-related emissions and exposure and the ways of limiting them.
Atmospheric Environment, 2019
Inhalable particulate matter (size <2.5µm: PM 2.5) inside commuting and tourist buses moving through the city of Barcelona, Spain, was chemically analysed. The analyses show PM dominated by organic carbon (mostly 10-20 µg/m 3) and elemental carbon (mostly 3-6 µg/m 3 ; OC/EC=3.4), followed by SO 4 2 , Fe, Ca, K, Al 2 O 3 , Mg, and Na, with calculated mineral content being around one third that of total carbon. Elemental carbon levels are higher inside diesel buses than those powered by natural gas or electricity, and higher in the upper floor of open-top double decker tourist buses than in the lower floor. Overall, major element concentrations inside the buses are typically 2-8 times higher than 24haveraged urban background levels, although some metallic trace elements, notably Cu and Sb, are exceptionally enriched due to the presence of brake particles, especially on routes involving higher gradients and therefore more brake use. In contrast, Cu and Sb concentrations in electric buses are unexceptional, presumably because these buses rely more on regenerative braking and are hermetically sealed when moving. Seasonal differences reveal PM to be more mineral in winter (Al 2 O 3 1.3 µg/m 3 vs. summer average of 0.3 µg/m 3), with summer enrichment in Na, Mg, P, V, Ni and SO 4 2being attributed to marine aerosols contaminated by port emissions. Source apportionment calculations identify 6 main factors: road dust resuspension, metalliferous (brake wear and metallurgy), local urban dust, secondary sulphate and shipping (6%), vehicle exhaust (19%), and an indoor source (46%) interpreted as likely related to the textile fibres and skin flakes of bus occupants. Volatile Organic Compounds measured inside all buses except one were dominated by 2-Methylpentane (14-36 µg/m 3), Toluene (10-30 µg/m 3), Xylene isomers (10-28 µg/m 3 , with m->> o-> p-Xylene) and n-Pentane (5-15 µg/m 3). ƩBTEX concentrations were <70 µg/m 3 , with Toluene being commonest, followed by m-Xylene, with p-Xylene, o-Xylene and Ethylbenzene each below 7 µg/m 3 and Benzene concentrations always less than the EU limit value of 5 µg/m 3. The VOCs mixture is similar to that recently reported from inside Barcelona taxis (although inside the larger volume bus VOC concentrations are lower than in the taxis) and is interpreted as providing a chemical fingerprint characterising traffic-contaminated ambient air in the city road environment. The notable exception to the VOC content was a brand new hybrid diesel bus still offgassing volatiles to such an extent that Ʃ(alkane+alkene+aromatic) indoor concentrations exceeded 800 µg/m 3 , with ƩBTEX ten times higher than normal.
Airborne particulate matter at a bus station: concentration levels and governing parameters
Proceedings of the 10th …, 2005
Traffic emissions are an important contributor to ambient air pollution, especially in large cities featuring extensive and high density traffic networks. Bus fleets represent a significant part of inner city traffic causing an increase in exposure to general public, passengers and drivers along bus routes and at bus stations. Limited information is available on quantification of the levels, and governing parameters affecting the air pollution exposure at bus stations. The presented study investigated the bus emissions-dominated ambient air in a large, inner city bus station, with a specific focus on submicrometer particles. The study's objectives were (i) quantification of the concentration levels; (ii) characterisation of the spatio-temporal variation; (iii) identification of the parameters governing the emissions levels at the bus station and (iv) assessment of the relationship between particle concentrations measured at the street level (background) and within the bus station. The results show that up to 90% of the emissions at the station are ultrafine particles (smaller than 100 nm), with the concentration levels up to 10 times the value of urban ambient air background (annual) and up to 4 times the local ambient air background. The governing parameters affecting particle concentration at the station were bus flow rate and meteorological conditions (wind velocity). Particle concentration followed a diurnal trend, with an increase in the morning and evening, associated with traffic rush hours. Passengers' exposure could be significant compared to the average outdoor and indoor exposure levels.