The human biomonitoring (HBM) of metals is a part of the ongoing project SPoTT for the longitudinal health surveillance of the population living near a waste-to-energy (WTE) incinerator (Turin, Italy). The HBM of metals in the SPoTT population aimed to evaluate: i) reference values (RVs) before the WTE incinerator started operation; ii) differences in exposure by variables; iii) variations respect to other HBM studies; iv) exposure that exceeds the available health-based benchmarks as the Biomonitoring Equivalents (BEs) for urine Cd and Human Biomonitoring (HBM-I and HBM-II) values for urine Hg, Tl, and blood Pb; v) risk assessment by generating hazard quotients (HQs) for the single metal and hazard index (HI) for the co-occurrence of metals. Eighteen metals in urine and Pb in blood were determined by sector field inductively coupled plasma mass spectrometry. Metal concentrations were comparable with RVs reported in other countries, except for slightly higher As, Be, Ir, Pd, Pt, Rh, and Tl levels. Smoking was associated with Cd; age with Pb; drinking bottled water with As and Cd; consumption of fish with As and Hg; amalgams with Hg and Sn; dental restorations with Pd and Pt; use of jewelry with Co and Rh, and piercing with Ni. While HQs for urine Cd, Hg, Tl and blood Pb suggested that adverse effects were unlikely, the HQ value raised the question of whether additive interactions of these metals could produce health concern. The obtained HBM data can be an early warning for accumulations of metals and identification of subgroups at risk.