May lichen biomonitoring of air pollution be used for environmental justice assessment? A case study from an area of N Italy with a municipal solid waste incinerator

In this work, we aimed to identify the contribution of a municipal solid waste incinerator (MSWI) to the air contamination of a complex urbanized area of N Italy using lichen transplants as biomonitors, and to compare the values of contamination with the data of socioeconomic deprivation of the population living in the area. The method adopted allowed the identification of the elements of atmospheric origin that contaminate the study area. Although not distinguishable from the background, the contribution of the MSWI could be apportioned and mercury emerged as atmospheric tracer. Although not posing immediate risk, it is advisable to monitor in time the accumulation of Hg in biological systems. Consistently with similar studies, in the surrounding of the MSWI, we observed also the highest socio-economic deprivation. Overall, we found a close correlation between socioeconomic deprivation and air pollution, clearly showing that the most disadvantaged population is clustered in the most polluted areas.