Investigation of heavy metal concentrations on urban soils, dust and vegetables nearby a former smelter site in Mortagne du Nord, Northern France

Environmental situations near former industrial sites like Mortagne du Nord (Northern France) in which the soil, dust and homegrown vegetables have been contaminated by heavy metals can represent a sanitary risk to the surrounding population. In order to evaluate the contamination level in different exposition media in this site, 26 urban topsoils, 17 dust and 38 vegetable samples were taken near the former zinc smelter site. All the observed levels on urban soil samples (except one) are over regional agricultural reference values for Cd and Pb. 45 % of the vegetable samples are over the European foodstuff limits and one dust sample taken in the school playground outdoor tarmac area exceeds the French limit in dust set up at 1,000 μg m−2 for Pb. The Cd and Pb levels fluctuate depending on the use of the ground (kitchen garden, lawn, courtyard) and its location. The lack of simple correlations between the distance from the former smelter site and the Pb concentrations on sampled soils let us think that human activities contributed in the local urban contamination. In this context, who is now responsible for the soil contamination and the human exposure?