Using lichen biomonitoring to assess environmental justice at a neighbourhood level in an industrial area of Northern France

Environmental inequalities are based on the proximity of socio-economically disadvantaged populations to sources of environmental and public health risks, and have recently been extended to environmental contamination. We evaluated such inequalities using a novel approach, at the scale of neighbourhoods in the industrial area of Dunkerque, France, by associating an index of social disadvantage with environmental biomonitoring measurements.A Localised Disadvantage Index (LDI), which characterises the socio-economic status of populations at a neighbourhood level, was developed using an eco-sociological approach. The burdens of 18 trace elements (TE) were recently determined using samples of epiphytic lichens, collected within the study zone. A mean value of TE burden was modelled for each neighbourhood and an integrated index (Mean Impregnation Ratio, MIR) was generated to assess the level of multi-metallic contamination.LDI mapping reveals socio-economic disparities. The neighbourhoods situated near to factories are the most disadvantaged. Environmental maps reveal high contaminations in the vicinity of the industrial zones. The LDI is significantly correlated with the MIR, and with 16 of 18 TE. Significant differences in the level of contamination are observed between high- and low-deprived neighbourhoods.Our results uncover the presence of environmental inequalities. The most disadvantaged populations live in a strongly contaminated environment. We have pioneered the use of biomonitoring data and an integrated index of contamination for the prospection of environmental inequalities.