Health-related reference intervals for heavy metals in non-exposed young adults

Objectives Heavy Metals (HMs) concentrations vary with living environments, diet, and personal habits. This study aims to establish health-related reference intervals (RIs) for selected HMs in healthy, non-occupationally exposed young adults living in an urban environment.Methods The Uni4Me study enrolled 154 healthy university volunteers (median age: 23 years) to assess the concentrations of seven heavy metals (lead, nickel, cadmium, zinc, chromium, cobalt, and mercury) using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-EOS). CLSI guidelines were followed to estimate the 2.5th and 97.5th percentiles as RIs.Results Most metals were detected at low concentrations. Zinc showed consistent physiological levels in all participants. Mercury and chromium were the most frequently detected, indicating potential environmental or dietary exposure.Conclusions This study defines baseline values for HMs in an urban, healthy, young adult population. These results may support future biomonitoring efforts and public health initiatives targeting subclinical exposure in non-occupationally exposed populations.