An evaluation of equity in traffic-related air pollution generation and exposure

摘要

The distribution of traffic-related air pollution generation, exposure and social disadvantage is animportant environmental justice concern. From a social equity perspective, many questions ariseat the metropolitan scale: Do socially disadvantaged communities have higher exposure levels totraffic-related air pollution? Does a polluter-pays situation exist wherein communities thatgenerate high levels of pollution are also exposed to greater concentrations? And, is there arelationship between the polluter-pays principle and social disadvantage? These questions areexamined for the Montreal metropolitan region through the development of an integratedtransport and emission model. Two measures of traffic-related air pollution from private vehicleoperation are estimated at the traffic analysis zone level: (1) generation (average emissions perhousehold), and (2) exposure (average residential zone concentration). A social disadvantageindex is also calculated that incorporates elements of social and material deprivation. Threelevels of inequity exist regarding emissions, exposure and socioeconomics. Firstly, socialdisadvantage was found to have a positive relationship with exposure, meaning that the mostsocially disadvantaged communities tend to experience the highest levels of traffic-related airpollution. Spatial gradients in emission generation versus exposure are also present for most ofthe metropolitan region, negating the polluter-pays principle. Furthermore, the communities thatface a double-burden of greater disadvantage and higher exposure also tend to create the lowestquantities of pollution.