Assessment of Arsenic and Lead in Urban Park Soils in Newark, New Jersey, USA

Soils in seven urban parks in Newark, New Jersey (NJ), United States, were evaluated for arsenic (As) and lead (Pb) by field and laboratory methods. Surface (S1, 0–3 cm) and near-surface (S2, 4–7 cm) soils in high-contact areas of the parks were analyzed by portable X-ray fluorescence (XRF) spectroscopy. Median concentrations of As and Pb in S1 profiles were higher than median concentrations in NJ Urban soils. In S1 and S2 profiles, 39–50% of As and 56–58% of Pb concentrations exceeded the NJ Department of Environmental Protection limits for residential soils, with most hotspots located in two of the seven parks. The contamination factor (CFAs = 1.5–4.3; CFPb = 1.7–9.8), enrichment factor (EFAs = 1.7–4.6; EFPb = 2.0–10.4), and geoaccumulation index (Igeo As = −0.1–1.5; Igeo Pb = 0.1–2.7), calculated relative to NJ Rural soil concentrations, confirmed the contamination of park soils with As and Pb, with higher contamination and enrichment indices for Pb. Tessier sequential extraction indicated the metals were mostly in the reducible fraction, with median values of 80% As and 65% Pb bound to iron and manganese oxides. The fractionation suggests limited environmental mobility of the metals under current soil conditions. However, human exposure to As and Pb remains a concern as the soils are located in high-contact recreational areas.