Exposure and Health Impact Assessment of Essential and Non-Essential Elements in Rice Sold on Ghanaian Markets

Abstract

This present study investigated the presence, levels and health impact of some trace elements in rice sold on some Ghanaian markets using an inductively coupled plasma mass spectrometry (ICP-MS). A qualitative scan and a further quantification with the ICP-MS revealed the following elements; boron (B), phosphorous (P), calcium (Ca), iron (Fe), zinc (Zn), nickel (Ni), sodium (Na), molybdenum (Mo), silicon (Si), copper (Cu), sulphur (S), cobalt (Co), potassium (K), lithium (Li), manganese (Mn), magnesium (Mg), chromium (Cr), Silver (Ag), beryllium (Be), aluminium (Al), strontium (Sr), tin (Sn), antimony (Sb), lead (Pb), titanium (Ti), vanadium (V), yttrium (Y), zirconium (Zr), barium (Ba), bismuth (Bi), arsenic (As) and cadmium (Cd). The concentration of essential and non-essential metals follows the order: S > K > P > Mg > Ca > Si > Na > Zn > Mn > Fe > Cu > B > Mo > Ni > Co > Li and Al > Bi > (Sn and As ) > Ba > Sb > Sr > Be > Ti = V > Pb > Cd > Zr > Ag > Y respectively. The results showed that rice on sale on the Ghanaian markets are rich sources of S, K, Mg and Ca with moderate levels of essential minerals like Fe, Mn, Zn and Cu. The health impact assessment revealed that As, Sb and P all recorded hazard quotients greater than one. This implies that As, Sb and P could accumulate and adversely affect the health of Ghanaian adolescents, adults and the aged. The likely cancer risk (LCR) estimated from this study revealed that in children, adolescents, adults and the aged, As, Pb, Ni and Cd could individually and in combined accumulated concentrations induce carcinogenicity to consumers in Ghana overtime since the LCR and Total Likely Cancer Risk (TLCR) all exceeded the maximum safe limit of 1×10− 4.