Estimation of Toxicity Equivalency and Probabilistic Health Risk on Lifetime Daily Intake of Polycyclic Aromatic Hydrocarbons from Urban Residential Soils

ABSTRACT

In this study, toxicity equivalents and health risks, based on concentration of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban residential soils were estimated for the human population in Gwalior, India. Benzo(a)pyrene total potency equivalents (BaP TPE) were estimated for assessment of human health risk from direct contact with PAH-contaminated soil. Potential risk to contaminated groundwater from leaching of carcinogenic PAHs was assessed by estimating the index of additive cancer risk (IACR). On the basis of lifetime average daily intake of 16 PAHs through ingestion of PAH-contaminated soils, lifetime cancer risk to human adults and children was estimated. The concentration of probable human carcinogenic PAHs in soils accounted for 38% of ∑16PAHs. BaP TPE and index of additive cancer risk (IACR) were lower than guideline values of 0.6 mg kg⁻¹ and <1, respectively. Estimated lifetime average daily intakes of PAHs via soil ingestion were lower than recommended dose. However, the ILCR for human adults was within acceptable limits recommended by regulatory agencies, but may need action for children in Gwalior, India.

Key Words:

• residential soil
• priority PAHs
• benzo(a)pyrene total potency equivalent (BaP TPE)
• index of additive cancer risk (IACR)
• average daily intake
• incremental lifetime cancer risk (ILCR)

ACKNOWLEDGMENTS

The authors are grateful to the Central Pollution Control Board for providing the necessary infrastructure to conduct the present work. The views expressed in this article are those of authors and do not necessarily reflect the organization's. The authors also thank HERA's editors for their editing of our article.