Mass concentration and health risk assessment of heavy metals in size-segregated airborne particulate matter in Changsha

• Size-segregated APM was collected using an 8 Stage Non-Viable Cascade Impactor.
• Concentrations of size-segregated APM and HMs in size-segregated APM were measured.
• Health risk of HMs in APM was assessed by hazard quotient and cancer risk.
• Non-carcinogenic health effect existed in the APM.
• Cancer risks of Cd, Ni and Cr were all below the safe level.

This study was performed to investigate the concentration and the health risk of heavy metals (HMs: Zn, Pb, Cd, Ni, Fe, Mn, Cr and Cu) in size-segregated airborne particulate matter (APM). APM samples were collected into 9 size fractions (> 9.0 μm, 5.8–9.0 μm, 4.7–5.8 μm, 3.3–4.7 μm, 2.1–3.3 μm, 1.1–2.1 μm, 0.7–1.1 μm, 0.4–0.7 μm, < 0.4 μm) by an 8 Stage Non-Viable Cascade Impactor in the campus of Hunan University in Changsha. And then 9 fractions of APM were analyzed for HMs by ICP–OES. The total size-segregated APM concentration in the campus of Hunan University ranged from 120.24 to 271.15 μg/m3, and the concentration of HMs in APM was in the range of 38.08–13955.14 ng/m3. The health risk of HMs in APM was evaluated by hazard quotient (HQ) and hazard index (HI) and the results showed that dermal contact and ingestion of APM were the major exposure pathways to human health. The HI values of Cd, Mn, Pb and Cr for children and Cd, Mn and Pb for adults exhibited to be higher than 1 indicating that a non-carcinogenic health effect existed in the APM of the campus of Hunan University. The carcinogenic risks of Cd, Ni and Cr were all bellow the safe value.