Non-carcinogenic and carcinogenic health risks associated with heavy metals and polycyclic aromatic hydrocarbons in well-water samples from an automobile junk market in Ibadan, SW-Nigeria

Adeola Anike Oni; Stephen Olufemi Babalola; Adeyeri David Adeleye; Temidayo Ebenezer Olagunju; Ijeoma Anthonia Amama; Esther Onaopemipo Omole; Ezra Ajibola Adegboye; Obokparo Godspower Ohore

doi:10.1016/j.heliyon.2022.e10688

Non-carcinogenic and carcinogenic health risks associated with heavy metals and polycyclic aromatic hydrocarbons in well-water samples from an automobile junk market in Ibadan, SW-Nigeria

Heliyon. 2022 Sep 22;8(9):e10688. doi: 10.1016/j.heliyon.2022.e10688. eCollection 2022 Sep.

Authors

Adeola Anike Oni¹, Stephen Olufemi Babalola², Adeyeri David Adeleye¹, Temidayo Ebenezer Olagunju², Ijeoma Anthonia Amama¹, Esther Onaopemipo Omole¹, Ezra Ajibola Adegboye¹, Obokparo Godspower Ohore³

Affiliations

¹ Department of Zoology, University of Ibadan, Ibadan 200284, Nigeria.
² Department of Biology, Alex Ekwueme Federal University, Ndufu-Alike Ikwo, Nigeria.
³ Department of Veterinary Pathology, University of Ibadan, Ibadan 200284, Nigeria.

Abstract

Unserviceable vehicles imported from developed countries are often dismantled in automobile junk markets and the useable parts sold. This generates hazardous waste oils which contain contaminants detrimental to the environment and human health. In this study, we quantified the potential human health risks associated with oral and dermal exposure to heavy metals and PAHs in well-water samples from a major automobile junk market in Ibadan, SW-Nigeria. Twenty-four to thirty-one water samples from seven wells within the market were analyzed for seven metals and eight PAHs using standard methods. Hazard-Quotient (HQ), Hazard-Index (HI), and Carcinogenic-Risk (CR) were computed for children and adults based on the USEPA Human-Health Risk Assessment model. Iron, Lead, Arsenic, Cadmium, Benzo(a)Anthracene, and Benzo(a)Pyrene exceeded regulatory limits. In children and adults, lead (1.14-3.71), cadmium (1.26-2.60) and arsenic (1.03-4.33) had HQ_ingestion values exceeding 1. In addition, cadmium also posed risks via the dermal route in children in two of the seven sampled wells with an HQ of 1.76. Hazard Index was >1 via both routes in children (HI_ingestion:- 5.04-10.07; HI_dermal:- 1.12-2.12) but only via ingestion in adults (HI _ingestion:- 2.36-4.85). Well-3 samples posed the greatest non-carcinogenic risks via ingestion with HI values of 10.07 (children) and 4.85 (adults) respectively. Cadmium, arsenic, lead, and chromium could also elicit carcinogenic risk, with CR values of 1.00E - 02, 1.95E - 03, 1.11E - 04, and 3.30E - 04 which exceeded the 10^-4 limit indicating high risk, particularly in children. However, HQ and HI values for PAHs were <1 via both pathways suggesting no non-carcinogenic risk from PAH exposure. Carcinogenic risk estimates for Benzo(a)Anthracene (9.66E - 04) and Benzo(a)Pyrene (2.31E - 04) suggest moderate risks in exposed children via the dermal route. Adverse health effects including cancer may occur in the exposed population on prolonged usage of these polluted water sources. Urgent remediation measures are therefore necessary to protect the exposed population.

Keywords: Araromi; Automobile scrap; Cancer risk; Groundwater; Hazard index; Hazard quotient; Ibadan.