Every Breath You Take? Environmental Justice and Air Pollution in Christchurch, New Zealand

In a number of environmental-justice studies it has been noted that the exposure to an array of air pollutants varies between different social groups. This inequality in exposure is one possible explanation for the variations in pollution-related health outcomes such as lung cancer and other respiratory diseases. Previous environmental-justice studies that have focused upon air pollution have tended to be concerned with exposure to industrial and vehicle pollution and rely upon simple estimates of exposure, ignoring the complex interaction of emissions, topography, and meteorology that determine pollution levels in many urban areas. In this paper we use accurate and geographically detailed estimates of pollution calculated from an atmospheric dispersion model to examine issues of environmental justice related to air pollution sourced from domestic heating in Christchurch, New Zealand, a city with particularly high levels of particulate pollution during winter months. We consider whether there is a social gradient in exposure to air pollution in Christchurch by comparing estimates of particulate pollution for small areas across the city to a range of demographic and socioeconomic indicators including age, ethnicity, income, and deprivation. Furthermore, we examine whether there is a social gradient in exposure to extreme pollution episodes. We demonstrate that different social groups in the Christchurch population are exposed to different levels of both ambient air pollution and extreme air-pollution episodes. In particular, pollution is significantly higher among more disadvantaged communities. We also find evidence which suggests that the groups responsible for producing a large proportion of the pollution in Christchurch are not the same groups exposed to high levels of particulate air pollution.