title: Exposure to air pollutants during commuting in London: Are there inequalities among different socio-economic groups?
abstract: People with low income often experience higher exposures to air pollutants. We compared the exposure to particulate matter (PM1, PM2.5and PM10), Black Carbon (BC) and ultrafine particles (PNCs; 0.02-1μm) for typical commutes by car, bus and underground from 4 London areas with different levels of income deprivation (G1to G4, from most to least deprived). The highest BC and PM concentrations were found in G1while the highest PNC in G3. Lowest concentrations for all pollutants were observed in G2. We found no systematic relationship between income deprivation and pollutant concentrations, suggesting that differences between transport modes are a stronger influence. The underground showed the highest PM concentrations, followed by buses and a much lower concentrations in cars. BC concentrations in the underground were overestimated due to Fe interference. BC concentrations were also higher in buses than cars because of a lower infiltration of outside pollutants into the car cabin. PNCs were highest in buses, closely followed by cars, but lowest in underground due to the absence of combustion sources. Concentration in the road modes (car and bus) were governed by the traffic conditions (such as traffic flow interruptions) at the specific road section. Exposures were reduced in trains with non-openable windows compared to those with openable windows. People from less income-deprived areas have a predominant use of car, receiving the lowest doses (RDD<1μgh-1) during commute but generating the largest emissions per commuter. Conversely, commuters from high income-deprived areas have a major reliance on the bus, receiving higher exposures (RDD between 1.52 and 3.49μgh-1) while generating less emission per person. These findings suggest an aspect of environmental injustice and a need to incorporate the socioeconomic dimension in life-course exposure assessments.
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors.forename: Ioar
authors.initials: I
authors.lastname: Rivas
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Environmental Flow (EnFlo) Research Centre, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom. Electronic address: P.Kumar@surrey.ac.uk.
authors.forename: Prashant
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors.forename: Alex
authors.initials: A
authors.lastname: Hagen-Zanker
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis; D006801:Humans; D008131:London / Q000453:epidemiology; D052638:Particulate Matter / Q000032:analysis*; D012959:Socioeconomic Factors; D014186:Transportation; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: Black carbon; Environmental justice; Particulate matter; Personal exposure; Travel mode; Ultrafine particles