Determination of some heavy metals and their potential risk in selected vegetables on sale within Kaduna Metropolis, Kaduna State, Nigeria

Abstract

Background

Heavy metals in food, such as vegetables, may pose a serious health danger, making their consumption a public concern.

Objective The purpose of this study was to evaluate the dietary intake of heavy metals and their potential health risks in some vegetables consumed in Kaduna Metropolis.

Methods

Commonly consumed vegetable samples were purchased from five markets in Metropolis using random systematic sampling. These samples were rinsed, air dried, pulverised, and allowed to pass through a British Standard (BS) mesh (BS 125mm). The same vegetable types (5) from the same market were composed by the coning and quartering method, which was eventually analysed using a non-disruptive Energy Dispersive X-ray Fluorescence (ED-XRF) spectrophotometric method for heavy metal content.

Results

Estimated Maximum Daily Intake (EMDI), hazard quotient (HQ), hazard index (HI), and incremental lifetime cancer risk (ILCR) for both adults and children were used to quantify the potential public health risk posed by the consumption of these vegetables. The total average concentrations of the heavy metals and their EMDI were ranked as follows: iron > copper > zinc > manganese > molybdenum > chromium > cobalt > nickel. With a few exceptions, the non-carcinogenic risk (HQ and HI values) for the majority of the vegetables was excessive (> 1) for both adults and children. Both adults and children show moderate to high carcinogenic health risks for three of the heavy metals (Cr, Cu, and Ni) examined for carcinogenic health risk (ILCR), with the exception of a few vegetables.

Conclusion

This study gave an insight into possible potential high risk of both non-carcinogenic and carcinogenic health risks from the consumption of vegetables on sale in Kaduna metropolis. Consequently, there is need for prompt action to control heavy metals sources in the environment as well as vegetables to protect public health.