Incorporating bioaccessibility into human health risk assessments of heavy metals in urban park soils

file] 2012, 424, 79-87 (Eng) Urban soil pollutants can pose significant direct human health risks via oral ingestion, particle inhalation, and dermal contact, particularly for children in public parks. Non-carcinogenic and carcinogenic risks of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) were characterised in 40 surface soils (exposed lawns) from 14 urban parks in Xiamen, China. Results based on total metal concentrations may over-estimate actual risks versus an oral bioaccessibility assessment estimated using a simplified physiological-based extraction test. After considering the soil-specific bioaccessibility (Cd >Cu > Pb > Mn > Zn > Co > Ni > Cr), the non-cancer hazard of Pb to children via oral ingestion should be a consideration though its Hazard Index (HI) was below one. Overall cancer risk to adults still exceeded the target value (10-6), mainly due to Cr (93.8%) and Pb (6.19%) via dermal contact (68.3%) and oral ingestion (30.4%). The authors concluded that to produce more realistic estimates for human health risks from metal polluted urban soil, a framework combining land use type and bioaccessibility is recommended and should be applied to derive risk-based, site-specific soil guidelines.

Authors: Luo, Xiao-San; Ding, Jing; Xu, Bo; Wang, Yi-Jie; Li, Hong-Bo; Yu, Shen ;Full Source: Science of the Total Environment [online computer ;