Occurrence of Aflatoxin in Three Selected Smoked-dried Fish Species and its Risks on Human ealth from Niger South, Niger State, Nigeria

Abstract

Food contamination is a critical public health concern at the global level. Aflatoxins are mycotoxins produced by strains of Aspegillus flarns and spengillus parasitius, from fungi as their toxic secondary metabolites. Smoke-drying of fish popular traditional method and smoked-dricd fish is mostly consumed in Nigeria. This study aimed to evaluate the occurrence of total aflatoxins in three selected smoked- dried fish species (Clarias guriepinus, Prototems annectens and Orochromis nilolicus) and the extent of the threat it might pose on human health. The study was carried out from three (3) riverine communities in Niger State, comprising of katcha, Muregi and Nupeko. A total of 18 samples comprising of Clarias garicpinus, Prototems annectens and Oreochromis niloticas intended for human consumption were analyzed based on scasons. The lowest aflatoxin concentration value obtained is (0.103 ug/kg) of Clarias garicpinus from Muregi and Clarias gariepinus from Nupcko have the highest aflatoxin value (3.59 ug/kg). The investigation was carried out using the enzyme-linked immunosorbent assay (ELISA) Kit. All the three (3) sampling stations show the presence of aflatoxin in all the fish samples from both seasons cxcept the samples from katcha in dry season, which showed (0ug/kg). None of the value of Aflatoxin concentration from the fish samples exceeded the maximum level permitted (4/gkg1) by Europcan Union, (20g-kg-1) by Joint FAO/WHO Expert Committee on food additives (JECFA) and (15ug/kg) by United State and Food and Drug Administration. The risk calculated showed that the estimated daily intake (EDI) values of Aflatoxin was found higher in children (0.175 g/kg/day, 0.196 g/kg/ day and 0,413 g/ kg/day) in Niger South (katcha, Muregi and Nupcko) followed by adolescent (0.098 g/kg/day, 0.110 g/kg/day and 0.232 g/kg/day) and adult (0.075 ug/kg/day, 0.084 ug/kg/day and 0.177 g/kg/day), the margin of exposure (MOE) values was lower in children (114.3, 102.0 and 48.4), followed by adolescent (204.1, 181.8 and 86.2) and adult (266.7. 238.1 and 113.0). AIl Moe values were < 10,000, wlhich indicates possible health risk to consumers. The lower the value to 10,000, the higher tlhe margin of exposure, the result showved children are more at risk compare to adult. According to the findings, the higher the degree of dryncss in Smoked-dricd fish the lower the chances of Aflatoxin contamination. Therefore, there is a need for the fishermen and the marketers to adopt a better method of preservation and storage and it will be necessary to estimate the assessmnent risk on infants, to understand the cxtent of aflatoxin contamination.