Potentially toxic metals in road dust: An assessment of ecological and health risks at Woldia and Kobo towns in North Wollo, Ethiopia

ABSTRACT

The accumulation of heavy metals (HMs) in the environment threatens the ecosystem and human well-being. This study investigated the amounts of Mn, Fe, Ni, Co, Cu, Zn, Cd, Hg, Pb, As, and Cr, as well as the associated health and ecological risks. Thirty samples of roadside dust were collected in the northern Ethiopian towns of Woldia and Kobo. The collected samples were digested using acid digestion method and the levels of heavy metals were analysed using inductively coupled plasma optical emission spectroscopy. The results showed that the average concentrations of HMs were 0.103 (As)-7.6 (Cd) and 0.083 (Cd)-3.80 (Fe) mg/kg in Woldia and Kobo, respectively. All the HM concentrations investigated in this study were lower than the average global concentration, except for Hg in both towns and Cd in Woldia town. Analysis of variance (ANOVA) for the heavy metal concentration showed a significant difference across each sampling site, while Ni and Hg did not show a significant difference. The hazard quotient (HQ) and hazard index (HI) values of all HMs for adults and children through the three exposure routes were lower than 1, which means that they had a low likelihood of noncarcinogenic risks. The pollution index, geoaccumulation index, ecological risk index, integrated pollution index and risk index parameters were used to estimate the ecological risk. The results demonstrated that the pollution level mainly varied between low and moderate levels, except in Woldia, which is highly polluted by Cd metal that further detailed research is highly recommended to find out the sources of this metal.

KEYWORDS:

• Potential toxic metals
• road dust
• health risk
• ecological risk
• Ethiopia
• ICP-OES

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contribution

Asamene Embiale Taye designed the study, executed the study, analysed the data and wrote the manuscript. Bhagwan Singh Chandravanshi contributed to the manuscript preparation and proofreading. All authors approved the final version of the manuscript.

Data availability statement

The data used to support the findings of this study are included in this study.

Ethical responsibilities of authors

All authors have read, understood, and complied as applicable with the statement on ‘Ethical responsibilities of Authors’, as found in the Instructions for Authors.

Additional information

Funding

No funding was received for conducting this study.