Assessment of concentrations of selected elements in crustaceans and their potential health risk at Qua Iboe Estuary, Akwa Ibom State
| dc.contributor.author | Ekemini, Essien Sunday | |
| dc.date.accessioned | 2026-03-21T09:00:50Z | |
| dc.date.available | 2026-03-21T09:00:50Z | |
| dc.date.issued | 2021-06 | |
| dc.description | This thesis is for the award of Master of Science (MSc.) in Environmental Management | |
| dc.description.abstract | The present study was conducted to assess the accumulation of some metals (Pb, Cu, Zn, Cd, and Mn) in the tissues (exoskeleton, muscles, appendages and gills) of Procambarus clarkii, and Callinectes amnicola, in Qua Iboe Estuary, Akwa Ibom State. Four locations: Mkpanak, IwoOkpom, Ukpenekang, and Ifiayong (serving as control) were chosen for the study. Water and Sediment samples were also collected from the same locations. Standard procedures were employed in sample preparation, and the heavy metals concentrations were determined using Atomic Absorption Spectrophotometry (AAS). The results obtained showed that the various concentrations of the metals in the water were in the order Mn > Cu > Zn > Cd > Pb at all study locations. Average concentrations of Cd (0.058±0.01mg/l) and Mn (1.086±0.81mg/l) in water were found to be higher than the WHO, EPA, TSE and NIS permissible range, while others (Pb, Cu, and Zn) were within the range. Furthermore, concentrations of metals in the sediment were higher than their values in the overlaying water at all locations. All concentrations of metals in sediment were within the WHO and EPA allowable limit except for Mn. The concentrations of Cu and Zn in the crustacean tissues were lower than the permissible levels prescribed by WHO and EPA. However, Pb, Cd and Mn exceeded the allowable limits given by these standards. The average estimated weekly intake (EWI) was considerably below the provisional tolerable weekly intake (PTWI) based on the FAO and WHO standards for all studied metals. The combined target hazard quotient for the studied metals in Crabs and Crayfish were 0.474 and 0.370, respectively, i.e., below 1, showing the absence of potential significant health risk through the ingestion of the crustaceans. The cancer risk factors for Pb (3.2 × 10-7 and 2.7 × 10-7 in crabs and crayfish, respectively) were below the acceptable lifetime carcinogenic risk (10-5). Relative to the allowable limits for metals in seafood, there was no sufficient accumulation of any of the investigated metals in the tissues of the crustaceans to indicate a potential significant health hazard from their consumption. The results of this study revealed a safe level of Pb, Cu, Cd, Zn, and Mn contents in the crayfish and crabs consumed by the estuarine population. | |
| dc.identifier.citation | Ekemini, E. S(2021). Assessment of concentrations of selected elements in crustaceans and their potential health risk at Qua Iboe Estuary, Akwa Ibom State [Unpublished Master's Thesis]. Federal University of Technology, Owerri, Nigeria | |
| dc.identifier.uri | https://repository.futo.edu.ng/handle/20.500.14562/2428 | |
| dc.language.iso | en | |
| dc.publisher | Federal University of Technology, Owerri | |
| dc.rights | Attribution-NonCommercial-ShareAlike 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-sa/4.0/ | |
| dc.subject | Metals | |
| dc.subject | accumulation | |
| dc.subject | crayfish | |
| dc.subject | crabs | |
| dc.subject | estuary | |
| dc.subject | Departmental of Environmental Management | |
| dc.title | Assessment of concentrations of selected elements in crustaceans and their potential health risk at Qua Iboe Estuary, Akwa Ibom State | |
| dc.type | Master’s Thesis |