Human Health Risk Assessment: a Case Study of Heavy Metals Accumulations in Tissues of Callinectus latimanus from Iko River, Eastern Obolo L.G.A., Akwa Ibom State

Heavy metals in food pose serious adverse health effects in exposed human populace. This study aims at assessing the human health risk of heavy metals in the tissues of Callinectus latimanus obtained from two sites (S1 and S2) in Iko River, Akwa Ibom State. The gills, muscles, and hepatopancreas of both male and female crab species were studied, and Cd, Ni, and Pb were the heavy metals of interest. The following heavy metal distribution were found in the tissues of Callinectus latimanus; Ni: hepatopancreas (95.7 – 111.6 mg/kg), gills (84.2 – 121.4mg/kg), muscles (91.6 – 100.2mg/kg); Pb: hepatopancreas (6.0 – 43.8 mg/kg), gills (<0.001 – 19.4 mg/kg), muscles (<0.001 – 6.7 mg/kg); Cd: hepatopancreas (0.6 – 71.3 mg/kg), gills (8.4 – 18.5 mg/kg), muscles (17.4 – 99.7 mg/kg), respectively. These results indicate a significant variation in the distribution of heavy metals in the tissues of male and female crabs under investigation. Levels of trace metals were higher in the female than those of the male, with the highest metal concentration recorded in the gills of female crab samples. The rank profile of trace metals in the crabs investigated, according to their mean values, were Ni > Cd > Pb for all study sites. The daily intake of metal (DIM) and health risk index (HRI), which were evaluated to assess the human health risk, were found to be higher than recommended levels. Target Hazard Quotient (THQ) values for all metals considered were far greater than 1 in all Callinectus latimanus tissues, except Cd in the hepatopancreas of the male and female crab species in S2, Pb in the gills and muscles of male and female crab species in S2.The health risk index (HRI) for all the studied tissues of Callinectus latimanus were generally greater than one except Pb of the gills and hepatopancreas of the male crab. Generally, THQ and HRI < 1 implies a minimal health risk to exposed populace, while THQ and HRI > 1 indicates potential health risk.