Determination of Heavy Metals Contamination on Smoked Fish Sold at Some Fish Markets in Borno State, Nigeria

Fish smoking is the oldest known traditional method of fish processing and preservation. Fish provide the protein needed for bodybuilding and repairs of tissues, and form part of a healthy balanced and nutritious diet. Heavy metal contamination on ingested food substances is an issue of a serious health concern due to their high level of toxicological effects on humans. Fish products may become contaminated during processing or as a result of the intake of heavy metals from a polluted aquatic environment. The study was aimed at assessing the level some Heavy Metal (Pd, Cr, Cd, Hg, and As) contamination of smoked fish sold at Maiduguri fish markets. Fish samples (Smoked and unsmoked) were obtained from 8 major fish markets in Borno State. The samples were oven-dried and grounded. The grounded samples were digested using concentrated nitric acid and hydrogen peroxide (2:1) v/v and analyzed for heavy metals using AAS both at the Chemistry Department, Yobe State University, Damaturu. The results obtained, reveals that Cr, As, and Hg concentrations were below the set national permissible limits as set by NAFDAC in all sampling stations in the study area while Pd concentration exceed the set permissible limit in sample station E and F (2.768 ± 0.251 and 2.602 ± 0.241 mg kg-1 respectively). Furthermore, Hazard index (HI) values of the heavy metals (Pd, Cd, Cr, As, and Hg) were all greater than 1, revealing an unacceptable level of non-carcinogenic adverse health effects. The study recommends a continuous assessment of the level of heavy metals in smoked fish from the study area.