The Legacy of Mercury Contamination from a Past Leather Manufacturer and Health Risk Assessment in an Urban Area (Pisa Municipality, Italy)

An abandoned open green space in the urban setting of Municipality Pisa (Tuscany, Italy) has been designed for renewal to foster development recreational activities and improve lives surrounding communities. However, geochemical site characterization revealed Pb, Cu, Zn Hg concentrations soil exceeding thresholds imposed by Italian regulations residential use. Cu contents likely reflect effects vehicle traffic, while contamination represents legacy a past artisanal tannery that used Hg(II)-chloride leather processing mid-1900s. Mercury is widely distributed area, with highest concentration uppermost layer, reaching about 170 mg/kg common dandelion rhizosphere. Chemical extractions thermal desorption experiments have indicated most elemental free matrix-bound fraction, possible minor amount (less than 4 wt%) HgS negligible methylated forms (0.1 wt%). The data suggest processes could reduce Hg2+ volatile Hg0. groundwater, hosted shallow aquitard was below 0.2 µg/L. presence chloride groundwater might result formation stable aqueous complexes, increasing release from solids. Future water quality monitoring hence recommended. risk assessment highlighted mercury carries non-cancerous effects, particular children, posing basis management planning.