Accumulation of heavy metals in fish, water, and sediment samples from Oguta lake.
Date
2024-08
Authors
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Publisher
Federal University of Technology, Owerri
Abstract
This work was carried out to ascertain the accumulation of heavy metals in fish, water, and sediment samples from Oguta Lake. Triplicate batches of the samples were taken from three sampling points along the river coast, and the physicochemical parameters were analyzed in the laboratory using gravimetric, titrimetric, and spectrophotometric methods. The concentrations of heavy metals (Pb, Cd, As, Ni, Mn, Cu, and Hg) in water, sediment, and fish, insect, snail, and algal species from the lake were analyzed using Atomic Absorption Spectrophotometer. Carcinogenic risk models were used to estimate the potential risks through the ingestion of fish, insects, snails, and algal in Oguta Lake. Pearson correlation multivariate analyses of variance (MANOVA) were used to analyze the inter-relationship among heavy metals in water and sediments. Seasonal variation and the correlation matrix (ANOVA) of heavy metals were analyzed. The results obtained showed that the mean concentrations of physicochemical parameters ranged as follows: Temperature (26.04-29.35); pH (7.17-7.77); Free CO2 (9.78-10.34); BOD (10.14-10.42); TDS (22.23-28.04); EC (0.30-0.49); DO (5.69-5.86); Total Hardness (18.49-21.00); Turbidity (15.0317.76); Alkalinity (15.64-16.66); Sulfate (2.19-2.55); Ammonium (0.26-0.40). Comparison with WHO guidelines indicated that most parameters assayed were within permissible limits. The mean concentrations of heavy metals in water were: Pb (0.19±0.05); Cd (0.41±0.07); As (0.01±0.001); Ni (0.59 ±0.1); Mn (0.02±0.006); and Cu (2.24 ± 0.31). while the mean concentrations of heavy metals in sediment were: Pb (0.26±0.04); Cd (1.04±0.15); As (1.02±0.16); Ni (1.22± 0.24); Mn (1.98±1.68); and Cu (1.87 ± 0.58). Positive correlations were observed for the following pairs of metals in water and sediments: Pbw and Nis (r = 0.356), Cdw and Nis (r =0.237), Cuw and Mns (r = 0.325), Cdw and Pbs (r = 0.969*), and Asw and Ass (r = 0.967) at p< 0.05. Bioaccumulations of heavy metals were in the following order: fish > algal > snail > insect. The estimated daily intake of heavy metals from consuming fish, algae, and snails indicated that none of the heavy metals currently pose a health risk to consumers of these organisms in the study area, based on the dose. The results obtained from this study showed that heavy metal pollution is not yet a significant problem in Oguta Lake as of the time of this investigation.
Description
Master's thesis in environmental conservation and management .
Keywords
Oguta lake, heavy metals, bioaccumulation, fish, insects, snails, argar, department of biological sciences
Citation
Shittu, U. A. (2024). Accumulation of heavy metals in fish, water, and sediment samples from Oguta lake. (Unpublished Master's Thesis), Federal University of Technology, Owerri