Assessment of Heavy Metals and Public Health Concern in Selected Fish Species in Lagos Lagoon, Nigeria

Abstract

The possibility of public health risk from the uptake of heavy metals such as Cadmium, Lead, Nickel, Manganese, Iron, and Zinc in eight selected resident fish species of Lagos Lagoon, Nigeria, was investigated. The fishes were Hemichromis fasciatus, Polydactylus quadrifilis, Monodactylus sebae, Citharichthys stampfili, Cynoglossus senegalensis, Scomberomorus tritor, Eucinostomus melanopterus, and Lutjanus goreensis. The sizes and weight of specimens were measured; concentrations of heavy metals were determined by Atomic Absorption Spectrometry; consumer hazard risk assessment, carcinogenic and non-carcinogenic risks estimation were calculated using equations. Total length of specimens ranged from 5.5 – 48.5 cm (mean, 19.9 ± 13.03 cm); total weight ranged from 5.0 – 376.00 g (mean, 228.88 ± 139.73 g). Mean concentrations of essential metals, Fe and Mn in C. senegalensis (58.39 mg/kg and 14.04 mg/kg), C. stampfili (45.47 mg/kg and 13.30 mg/kg), L. goreensis (58.61 mg/kg and 10.71 mg/kg) respectively were higher than the FAO/WHO permissible limits; concentration of Zn was exceeded in H. fasciatus (61.18 mg/kg). FAO/WHO limits were exceeded for Pb in C. senegalensis (5.01 mg/kg) and L. goreensis (5.17 mg/kg); Cd in L. goreensis (0.29 mg /kg) C. senegalensis (0.07 mg/kg), C. stampfili (0.07 mg/kg), P. quadrifilis (0.07 mg/kg) and H. fasciatus and Ni in H. fasciatus (0.83 mg/kg) and P. quadrifilis (0.61 mg/kg), which are potentially carcinogenic metals. However, the non-carcinogenic risk (THQ and HI) and target cancer risk (TR) assessment were less than 1, the critical limit. This indicated no adverse health risk from the consumption of any of the selected fishes.