Heavy Metal-Related Health Risk Assessment of Cultivated Plants Around a Cement Factory in Sokoto North Western, Nigeria

Abstract

The pollution of the environment by cement manufacturing companies is becoming a global concern, particularly in developing nations. This study assessed the levels of heavy metals and their associated health risks in sugarcanes (Saccharum officinarum), tomatoes (Solanum lycopersicum), and almonds (Prunus dulcis) cultivated in the vicinity of a cement factory in Sokoto, Nigeria. Samples of these plants were collected, treated, and then assayed for lead (Pb), copper (Cu), cadmium (Cd), and zinc (Zn) using atomic absorption spectroscopy (AAS). The values obtained were compared against the permissible limits established by the World Health Organization (WHO), and these results were used to estimate the potential health risks associated with consuming these plants. The findings revealed that both the Solanum lycopersicum and Saccharum officinarum contained non-tolerable levels of Cu, Cd, Pb, and Zn, while Prunus dulcis had non-tolerable levels of Zn only. Additionally, the concentrations of individual heavy metals in each of the three plant species showed a significant difference (p ≤ 0.05) from the respective WHO standards. The estimated daily intake (EDI) and target hazard quotient (THQ) for all the heavy metals were within the recommended limits, except for the EDI of Pb in Saccharum officinarum and the THQ of Pb in Solanum lycopersicum. The health risk index (HRI) for all the heavy metals in the three plants exceeded the tolerable limit (> 1). These findings indicate that daily consumption of these plants may pose health hazards. Therefore, the practice of cultivating plants in the vicinity of cement factories should be discouraged.