Human Health Risk Assessment of Heavy Metals and Hydrocarbons in Murraya koenigii in Rivers State, Nigeria

Background and Objective: The entry of contaminants into the environment due to human and natural actions is one of the major problems facing the ecosystem today. This study evaluated the human health risks and selected heavy metals and hydrocarbon composition of Murraya koenigiicommonly called curry leaves,harvested from selected communities in Eleme LGA. Materials and Methods: Fresh curry leaves were harvested in Aleto, Ogale, Akpajo and Alesa in Eleme Local Government Area of Rivers State, Nigeria and Rivers State University as a control sample. The curry leaves were ovum-dried for about two weeks, ground into powder and stored before analysis of heavy metals using an Atomic Absorption Spectrophotometer. Human health risk assessment from the consumption of the plant was computed using the standard formula as described by United States Environmental Protection Agency. Results: The heavy metal concentration in the samples was below the permissible limit of WHO except for Fe. Ogale had the highest concentration (961.768 μg/kg) of PAH while RSU recorded the lowest value (41.916 μg/kg). Indeno[1,2,3-cd]pyrene in the study areas was above WHO permissible limit. Human health risk assessment revealed that Ogale had the highest CF while RSU had the lowest. The EDI for all the heavy metals was within the USEPA permissible limits except Fe. The THQ had all its detected PAHs below the permissible limit of 1 except Benzo(a)pyrene. The cancer risk in all study locations of Eleme LGA exceeded the USEPA limit of 1×10^-4. Conclusion: The study suggests that consumption of the leaves of study poses both potential non-cancer health risks and cancer risks, thus, there should be regular monitoring of activities that lead to the presence of heavy metal and hydrocarbon pollution in the environment.