Exposure to air pollutants during commuting in London: Are there inequalities among different socio-economic groups?

Ioar Rivas,Prashant Kumar,Alex Hagen-Zanker

doi:10.1016/j.envint.2017.01.019

Ioar Rivas, Prashant Kumar + Show 1 more

Open Access

https://doi.org/10.1016/j.envint.2017.01.019

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Journal: Environment International	Publication Date: Feb 8, 2017
Citations: 111	License type: cc-by

Affiliation: University of Surrey

Abstract

People with low income often experience higher exposures to air pollutants. We compared the exposure to particulate matter (PM1, PM2.5 and 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 (G1 to G4, from most to least deprived). The highest BC and PM concentrations were found in G1 while 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.

Highlights

Air pollution is considered a major threat to human health because of its link to an increased mortality and loss of disability-adjusted life years (GBD 2013 Risk Factor Collaborators, 2015)
Such monitoring networks only provide a partial insight in personal exposure since this differs greatly with activity, location and time spent on each activity (Bekö et al, 2015; Buonanno et al, 2013; Rivas et al, 2016)
The route corresponding to G1 showed the highest concentrations for particle number concentrations (PNCs) (9335 cm−3) and all particulate matter (PM) fractions (PM1 = 14.7 μg m−3, PM2.5 = 19.5 μg m−3, PM10 = 33.9 μg m−3), with the G2 route having the lowest (PNC = 6273 cm−3, PM1 = 9.1 μg m−3, PM2.5 = 11.5 μg m−3 and PM10 = 20.9 μg m−3)

Summary

Introduction

Air pollution is considered a major threat to human health because of its link to an increased mortality and loss of disability-adjusted life years (GBD 2013 Risk Factor Collaborators, 2015). Black carbon (BC) is considered a better tracer of traffic emissions than particulate matter (PM) mass (Reche et al, 2011; WHO, 2012), especially for diesel-fuelled vehicles. Owing to their size, ultrafine particles (b100 nm) may affect human health more strongly than larger-sized particles (Chen et al, 2016a, 2016b; Kumar et al, 2014; Lanzinger et al, 2016) and should be included in exposure assessments next to other pollutants.

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