Determination of some heavy metal content in tilapia and cat fish species in Lake Njuwa, Adamawa State, Nigeria

A.S Ibrahim,U.A.S Zannah,M Umar,D Ibrahim,E.D Paul

doi:10.4314/jasem.v22i8.3

Abstract

Concentration (mg/kg) of Lead (Pb), Chromium (Cr), Copper (Cu), Nickel (Ni) and Cadmium (Cd) were measured in various organs (such as gills, bones and muscles) of Tilapia and Catfish collected from Lake Njuwa Adamawa state during dry season (February, 2017) and wet season (August, 2017). The results obtained were compared to permissible limits set by World Health Organization, WHO (1985), Food and Agricultural organization, FOA (2003), to ascertain its health implications. Comparison between the heavy metals concentration of dry and wet season were carried out using Mann Whitney u test, the relationship between the heavy metal concentration and the weight of the fish was carried out using Pearson correlation test. All the analysis were determined at significant level of p >0.05 using Microsoft excel 2010 and statistical package for social science (SPSS) 2.3. The results obtained shows that the heavy metals are more concentrated in the bones (2.30, 2.50, 1.37, and 1.40) than the gills (2.17, 2.20, 1.19 and 1.23) and the muscles (0.5, 0.7, 0.99 and 1.03) of both the Tilapia and Catfish during the wet season than the dry season. Keywords: Heavy metal, Tilapia fish, Catfish, Lake, dry season, wet season

Highlights

Fish is widely accepted because of its high palatability, low cholesterol and tender flesh, it is the cheapest source of animal protein and other essential nutrients required in human diet (Saduku and Olademeli, 1991)
Heavy metals may accumulate in aquatic species, enter the food chain and cause serious harm to human health when contamination content and exposure are significant (Goyer 1997; Papagiannis et al, 2004; Turkmen et al, 2005; Fenandes et al, 2007) they have been listed by the US environmental Agency (USEPA) based on their potential for human exposure and health risk (Birungi et al, 2007)
Several techniques have been used for determination of metal concentrations in fish species such as flame atomic absorption spectrometry (Abedin, 1986; ElMehdi, 1987; Ahmet, 1992; Petisleam et al, 2003; Petisleam et al, 2007), graphite furnace atomic absorption spectrometry (Sperling, 1988; Botson et al, 2004), electro-thermal atomic absorption spectrometry (Perez, 2001; Mendez, 2002), inductive coupled plasma (Chirila, 1999; Petisleam et al, 2005) and mass spectrometry (Sanchez, 2003; Petisleam et al, 2005) Different digestion methods were used as sample preparation methods for determination of heavy metals in fish samples (Olaifa et al, 2004)

Summary

Introduction

Fish is widely accepted because of its high palatability, low cholesterol and tender flesh, it is the cheapest source of animal protein and other essential nutrients required in human diet (Saduku and Olademeli, 1991). Heavy metals may accumulate in aquatic species, enter the food chain and cause serious harm to human health when contamination content and exposure are significant (Goyer 1997; Papagiannis et al, 2004; Turkmen et al, 2005; Fenandes et al, 2007) they have been listed by the US environmental Agency (USEPA) based on their potential for human exposure and health risk (Birungi et al, 2007). The levels of heavy metal accumulation in fish depend on the growth rate, metabolism, feeding pattern and ecological requirements of a given fish species (Yilmal et al, 2005, 2010).

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Conclusion