Incorporating oral, inhalation and dermal bioaccessibility into human health risk characterization following exposure to Chromated Copper Arsenate (CCA)-contaminated soils

• Published in: Ecotoxicology and environmental safety 2023-01, Vol.249, p.114446-114446, Article 114446
• Main Authors: Marin Villegas, Carlos A., Zagury, Gerald J.
• Format: Article
• Language: English
• Subjects: Human health exposure assessment; Human health risk assessment; In-vitro bioaccessibility; Metal(loid) pollution; Multi-pathway exposure
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.114446

Exposure to potentially toxic metal(loid)s (PTMs) in soil may happen via ingestion, inhalation, and dermal pathway. A more accurate risk characterization should consider PTM bioavailability. Using ten soil samples collected in the Montreal area (Canada) near CCA-treated utility poles, this study aims to characterize non-carcinogenic and carcinogenic human health risks associated with As, Cr, Cu, Pb, and Zn through a multi-pathway exposure approach. This innovative study incorporates, for the first time, the bioaccessible fraction of the metal(loid)s for three exposure routes and two different scenarios. For the residential and industrial scenarios, the oral and dermal pathways yielded a hazard index (HI) much higher than 1 with and without bioaccessibility considerations (range 1.7 – 349 without bioaccessibility and 0.8–134 with bioaccessibility), whereas the inhalation pathway caused a lower hazard (HI < 1). For the dermal pathway, the hazard quotient was higher when bioaccessibility of field-collected samples was considered due to inherent assumptions from the US EPA soil approach to calculate the dermal dose. For carcinogenic risk, As and Pb were the most significant contributors to risk for the oral pathway, followed by the same elements for the dermal pathway. The overall carcinogenic risk was higher than the acceptable risk ( > 10−4) with and without bioaccessibility considerations (range 1.9E-4 – 9.6E-3 without bioaccessibility and 6.8E-5 – 3.8E-3 with bioaccessibility). Bioaccessibility tests provide a more accurate assessment of exposure to PTMs compared to total concentrations in soils. [Display omitted] •Non-carcinogenic risk is associated with the oral and dermal pathways.•Main carcinogenic risk is associated with the oral pathway (As and Pb).•For some scenarios, there is a higher non-carcinogenic risk associated with the dermal than the oral pathway.•For the dermal pathway, HQ is higher when bioaccessibility is considered.•Inhalation pathway contribution to risk is very low.