Setting our sights on justice: Contaminated sites and socio-economic deprivation in New Zealand

Research in the United States has shown that living near to sites that have stored or used hazardous substances (hazardous substances sites) is a risk factor for illness. The poor and ethnic minorities are disproportionately represented in this housing and thus are exposed to greater potential health risks. There are more than 10,000 hazardous waste sites in New Zealand but no previous research has related their location to the degree of socio-economic deprivation of the resident population. The aim of this study was to determine the association between hazardous substances sites and the level of socio-economic deprivation of the surrounding neighbourhoods. Data on hazardous substances sites from the computerized database of the Wellington Regional Council was linked to meshblocks used in the 1991 New Zealand Census. Using multivariate analysis, the distribution of these sites across meshblocks was compared with the socio-economic deprivation of the NZDep91 Index of Deprivation for small areas. A strong positive relationship was found between the number of hazardous substances sites and the deprivation of the meshblock (Chi22 = 64.6, p <0.001). 40% of those living in the most deprived socio-economic meshblocks had hazardous sites in their area, compared to less than 10% of those in the most socio-economically advantaged areas. The authors concluded that the number of sites containing hazardous substances is directly related to the level of deprivation in the surrounding meshblock. This relationship raises serious issues about the additional environmental risks poor people are exposed to in New Zealand and the equity responsibilities of regional councils and the national government.