Assessment of Some Heavy Metal Content of Dried Crayfish Sold in Creek Road Market, Borokiri, Port Harcourt, Nigeria

Abstract

Heavy metals are elements that contaminate seafood and make them harmful to human health when present in quantities that are higher than the permissible limit. This study was conducted to determine some heavy metals such as lead and mercury contained in dried crayfish gotten from three different locations (Oron, Ataba and Nembe town in Akwa Ibom, Rivers and Bayelsa State respectively) and sold in the Creek Road Market, Borokiri, Port Harcourt, Rivers State. The dried crayfish samples were purchased randomly from marketers in the market. 5g of the dried crayfish samples with its different organs (Gills, muscle tissues) were ground into powdered form and digested with HNO3  using standard procedures   and analysed for lead and mercury using the micro plasma atomic emission spectrophotometric analyser. The results showed that Lead content in the dried crayfish from Oron, Ataba and Nembe were 0.140 ± 0.014 mg/kg, 0.040 ± 0.014 mg/kg and 0.016 ± 0.002 mg/kg respectively while for Mercury content, Oron crayfish contained 5.136 ± 0.017 mg/kg, Ataba 3.744 ± 0.017 mg/kg and Nembe 3.948 ± 0.023mg/kg. The mean values in the three different crayfish samples were significantly different (p<0.05). This result shows that the lead content present in the dried crayfish are within the permissible limit of 1 mg/kg as indicated by FAO hence safe for consumption purposes with no expected form of toxicity and health implication to consumers whereas for mercury content, the level was found to be above the permissible limit.