Human Health Risk Assessment of Heavy Metals in Spices Cultivated in Okrika, Rivers State, Nigeria

Abstract

The presence of Nickel (Ni), Chromium (Cr), Arsenic (As), Cadmium (Cd), Lead (Pb), Cobalt (Co) and Manganese (Mn) in spices grown in Okrika, Rivers State, Nigeria was determined in this work. Atomic Absorption Spectrophotometer (AAS) was used to determine these heavy metals. These heavy metals assessed were detected in all the spices investigated. The concentrations of Pb, Cd, As in all the samples investigated were above the safe limit set by the Food and Agricultural Organization(FAO) and World Health Organization(WHO) except for Cr which was only above the limit in curry spices. The estimated daily intake of heavy metal through the consumptions of these spices was less than the tolerable daily intake limit except for Cr in all the samples. The targeted hazard quotients for Pb, Cd, As in scent leaf spices and Cd, Ni, As in curry leaf spices were above 1 while Ni, Cr, Co and Mn in scent leaf spices and Cr, Pb, Co and Mn in curry leaf spices were below 1. Carcinogenic risk(CR) estimations for Pb, Cd, Ni, Cr and As showed that CR for Cr, Cd, As, Ni, in all the spices were far above the acceptable risk level of 10E-4 except for Pb which was within the acceptable range for both samples.  The results of this investigation showed that some of those spices from Okrika, Rivers State may not be safe for human consumption as a result of the high heavy metals contaminations observed.