Trace element risk assessment of an industrial waste site, a key diagnosis for selecting the most appropriate...

The management of polluted soils requires a comprehensive risk assessment, based on a combined human health and ecological risk, in accordance with the One Health concept. To this end, a risk assessment was carried out on a former industrial site, based on its potential future use as a recreational park. The site was divided into 20 zones, and trace element (TE) total and bioaccessible concentrations were measured. From those data, hazardous index (HI) and carcinogenic index (CI) were calculated. The accumulation of TEs into snail guts was also measured using a standard test. The HIs and CI values (based on bioaccessibility) for adults showed two zones with an unacceptable risk, due to high Pb concentrations, with HI of 1.77 and 19.24 and CI of 12.3e^-6 and 87.1e^-6. For children, almost half of the site presented unacceptable risks, due to high Pb, Zn, Ni and Cr contents. The HI ranged from 1.42 to 164, while the CI was above threshold only in one zone (63.4e^-6). In terms of ecological risk, the snail test revealed nine areas with no risk and 11 with uncertain risk. From this analysis, we could conclude on the future site management: (i) access to the area presenting an unacceptable risk to adults and children should be prohibited; (ii) for areas presenting risk to children but not to adults, access should be restricted to adults, by converting the areas into research areas; and (iii) areas presenting no risk to adults and children can be transformed into recreational areas.