Preliminary Assessment of Some Heavy Metals Pollution Status of Lisikili River Water in Zambezi Region, Namibia (Published)
Good water quality is fundamental to human health and sustenance of aquatic ecosystems. The Lisikili river in Zambezi region, Namibia is a major perennial river which serves diverse economic purposes in the host community. However, it is now receiving pollution threat from effluents discharge and surface run-off from large agricultural lands. Eight (8) water samples were collected at 8 random points within a stretch of approximately 2km on each extremity and median parts of the river. Two major economic fish from the river, tilapia fish (Oreochromis niloticus) and cat fish (Siluriformes) (8 samples of each) were collected using fish net at the points of water sampling. The samples were transported to analytical laboratory in ice boxes for processing and analyses for the levels of Pb, As, Cr, Cd, Cu, Zn, Mn and Fe using Inductively Coupled Plasma-Optical Emission Spectrophotometer (ICP: Perkin Elmer Optima 7000 DV). The results obtained showed wide mean concentrations of the heavy metals in the river water; iron recorded the highest level of 2.375 mg/l and arsenic (0.047 mg/l) recorded the lowest level. Apart from Zn (0.259 mg/l) and Cu (0.073 mg/l) with the present concentrations lower than their guideline permissible limits, the mean concentrations of the other heavy metals exceeded their maximum permissible guideline values for the protection of human and aquatic health. Based on the classification of metal pollution index (PI) for water, apart from Cu (PI = 0.03) and Zn (PI = 0.04); all the other heavy metals recorded pollution indices which suggest moderate to strong effect on the river water quality. In both the catfish and tilapia fish (wet weight whole sample), iron (4.926 mg/kg and 3.323 mg/kg) recorded the highest mean concentration while Cd (0.136 mg/kg and 0.078mg/kg) recorded the lowest level respectively. Generally, the present levels of the heavy metals were below their regulatory limits for the protection of human health. However, the fish’s bio-accumulation factors of the metals suggest that they have high potentials to bio-accumulate some of the heavy metals to high levels and this has adverse implication for human consumption. Because heavy metals are non-biodegradable and bio-accumulative in nature which therefore, make their presence in human foods even at very minute levels potential toxins, it is important to monitor their accumulations in the river and fish and advice precautionary measures to limit excessive human exposures to the heavy metals content.
Keywords: Fish, Heavy Metals, Human Health, Pollution, River Water
Environmental Impact of Microbes on Awba Dam; Its Effect on Ecotourism (Published)
Recreational use of water is often given inadequate consideration and care. This is of particular concern as the recreational use of water is becoming popular in Nigeria. Many of these are increasingly contaminated by domestic sewage and industrial effluents. This study is therefore relevant in assessing the environmental impact of microbes on ecotourism in Awba dam. A total of nine water (n=9) and soil (n= 9) samples were collected at entry, middle and the end of the Awba dam for heavy metal analysis and microbial assay. Samples were assessed for heavy metals using an official procedure and atomic absorption spectrophotometry. Total aerobic plate count, Isolation and characterization of strains was done using standard methods. For enumeration of E. coliO157:H7, colonies were characterized using standard methods. The direct slide agglutination technique was utilized for serology. The presumptive E. coli isolates were subjected to agglutination tests with specific E. coli O157:H7 . For the antibiotic sensitivity test, the Bauer-Kirby disc diffusion method was used to test the sensitivity of the isolates. Statistical analysis of ANOVA was used and Duncan multiple range test was used to separate the means. All the values obtained for the total aerobic count and total coliform count for soil and water were higher than EPA recommended value for recreational waters. For the antibiotic Sensitivity Profile, isolates from Awba dam showed the highest sensitivity (16.17mm) to ciprofloxacin while lowest was with Augmentine (8.25mm).Furthermore the isolate from the control point showed highest sensitivity to CPR and NIT ( 14mm) and least for AUG (5mm) Generally, E.coliO157:H7 isolates were highly sensitive to Oflatoxin and Ciproflaxin(93.3%) while the isolate was completely resistant to Ampicilin and Cefuroxime. The presence of E.coliO157:H7 in the dam can make the dam unfit for recreational activities and also for the community household chores, if not well treated . The University management should device means of controlling waste water that enters into the dam by providing alternate channels of discharge .This will reduce the growth and spread of the microbes in the soil and water of the dam.
Keywords: E. coli O157:H7, Heavy Metals, Physico-chemical parameters, Total Coliform Count
Using EF, PLI and Igeo for the Assessment of Heavy Metal Pollution and Sediment Quality of Asejire Reservoir, Southwest Nigeria (Published)
Asejire Reservoir is the largest lake in Southwest Nigeria, supplying domestic and industrial water to more than two million inhabitants of Ibadan and adjoining villages and towns in Oyo and Osun States. A study on the characteristic of sediment quality was conducted to evaluate the heavy metal content of the reservoir. Twenty stations were selected, sampled and analyzed using standard methods.Standard pollution indices such as Igeo, Enrichment Factor, Contamination Factor and Pollution Load Index were deployed to assess the level of heavy metals contamination in the reservoir. The result showed that the sediment was slightly acidic across the study stations, with low conductivity and organic matter content. The heavy metals order of dominance was: Fe>Pb>Cu>Zn>Mn>Ba>Ni>Cr. The mean concentration levels of all the heavy metals were lower than mean background value except Fe and Pb. Analysed data shows that the sediments in the area are rich in Fe with Igeo values > 6, high enrichment and contamination factor. Igeo and CF levels of Pb indicate moderate to no pollution, while other heavy metals indicated low calculated Igeo, EF and CF respectively. The calculated PLI values for all the heavy metals in all the location were < 1, indicating low anthropogenic contamination by these elements and suggesting that the heavy metals were derived mainly from natural sources such as bedrock materials and weathering processes.
Keywords: Asejire, Geo-accumulation Index, Heavy Metals, Pollution Load Index, Sediment
Assessment of Selected Heavy Metal Residues in the Kidney, Liver, Muscle and Gizzard of Chickens Raised Within Enugu Metropolis (Published)
Studies were carried out for possible bioaccumulation of the following heavy metals; Pb, As, Cd, Cr, Hg, Ni, V and Cu in the internal parts (kidney, liver, gizzard and muscle) of twenty seven (27) local and exotic chickens raised within Enugu metropolis after wet digestion of samples and subsequent use of atomic absorption spectrometer. All the selected heavy metals were found to be present in the studied parts of the chickens although at concentrations within their respective established permissible limits for meats consumption. The internal organs of experimental chickens accumulated heavy metals in the following increasing order: liver > kidney > gizzard > muscle. Except vanadium, the concentrations of all other metals in the studied parts of the chickens showed significance at p < 0.05 from the anova analysis. The mean concentrations of Pb, Cd and Hg were very much higher in the kidney and liver the chickens than other studied metals. The experimental chickens accumulated heavy metals in the following increasing order: local chicken > layer chicken > broiler chickens.
Keywords: Bioaccumulation, Chickens, Heavy Metals, Kidney, Liver