Browsing by Author "Shisia, Silvanus"

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    Assessment of Heavy Metals Pollution in Urban Soils and the Implications to Consumers Health
    (Journal of Natural Sciences Research, 2015-01) Ngure, Veronica; Sitati, Noah; Shisia, Silvanus; Kinuthia, Geoffrey K.
    Elevated levels of metals due to anthropogenic activities are a cause of environmental concern because of their effects on human health. Eldoret Municipality, in Kenya, is one of the fastest growing municipalities with both industrial and agricultural developments. The study aimed at determining the concentration of five elements namely zinc (Zn), lead (Pd), copper (Cu), chromium (Cr) and cadmium (Cd) in five sample sites within the municipality and established the possible health risks in the residents. Measured concentrations of Zn, Pb, Cr, Cu and Cd in surface horizon soils were used to estimate the geochemical load indices and their spatial distribution. Four soil samples were collected monthly from each sample site on the same farms totaling 200 soil samples. The samples were dried, ground and sieved for metal digestion using varied acids in the laboratory and analysis was done against metal standards using Atomic Absorption Spectrometry (AAS). Only Cd concentration (0.0286mg/kg) in all sites was above the recommended unpolluted soils. Epidemiological data were obtained from the residents and hospitals to establish associated health risks. Determination of metals’ combined effects using multivariate Principal Component Analysis showed that varying concentrations of Zn and Pb tended to increase incidences of cancer, hypertension and stroke. Metals Zn, Pb and Cu concentrations correlated with development of cardiovascular diseases. Awareness rising to residents of Eldoret Municipality on high Cd concentration in the soil and use of alternative forms of fertilizers and related chemicals with low Cd content is recommended.
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    Concentration levels of potentially harmful elements from gold mining in Lake Victoria Region, Kenya: Environmental and health implications
    (Journal of Geochemical Exploration, 2014) Ngure, Veronica; Davies, Theophilus; Kinuthia, Geoffrey K.; Sitati, Noah; Shisia, Silvanus; Okoth, Elijah Oyoo
    Second only to the agricultural industry, mining is often considered to be the largest source of pollution in most mineral-rich countries. Minewastes and tailings commonly generate large concentrations of effluents containing high levels of potentially harmful elements (PHEs) which migrate into various compartments of the ecosystem with obvious undesirable health consequences. In this study, the concentrations of As Cd, Hg and Pb were determined on samples of soil, stream water and fish (Rastrineobola argentea) collected from the Migori Gold Belt (MGB) in Kenya. Maximum total concentrations of Cd, Pb, As and Hg recorded in some samples in the study area were found to be far above the World Health Organization (WHO) and the Food and Agriculture Organisation (FAO) maximum allowable concentrations (MAC), respectively, including some from the control site, 150 km away from the MGB. The calculated geometric means showed that the PHE concentrations were significantly above MAC levels (p b 0.05) in the three sample types. The PHE concentrations were as follows: in water, Cd: 1.5–10.5 μg l−1, Pb: 0.4–13.1 μg l−1, As: 0.06–23.0 μg l−1, and Hg: 0.36–52.1 μg l−1; in soil, Cd: 4.5–570 mg kg−1, Pb: 5.9–619 mg kg−1, As: 0.08–86.0 mg kg−1, and Hg: 0.51–1830 mg kg−1; and in fish; Cd, 1.9–10.1 mg kg−1, Pb: 2.0–13.1 mg kg−1, As: 0.02–1.92 mg kg−1, and Hg: 0.26–355 mg kg−1. Concentrations of PHEs were much higher in the area affected by gold mining area than at point S4 which was sampled for comparison and was 70 km away from the gold mining area. We conclude that gold mining and other human activities in the MGB have led to the release of toxic levels of Cd, Pb, As and Hg, which may lead to serious environmental health consequences in humans. We recommend that the public health sector addresses in a timely fashion, these sources of contamination (gold mining and associated human activities), in order to obviate impending health problems.
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    Health Implications of Heavy Metals in Soil, Scalp Hair and Selected Food Crops within Eldoret Municipality, Kenya
    (IOSR Journal Of Environmental Science, Toxicology And Food Technology, 2013-12) Ngure, Veronica; Sitati, Noah; Shisia, Silvanus; Simiyu, Gelas; Kinuthia, Geoffrey K.; Kelonye, Festus
    Heavy metals were analyzed in soils, food crops and male scalp hair samples collected from two age group subjects; adults (18 - 45 years) and old age (46 - 55 years) males from polluted and relatively less polluted areas in Eldoret Municipality environs, Kenya. The samples used were collected from same sites as the individuals who had stayed in the sampled regions for more than five years. The samples were digested using acids and analyzed using Atomic Absorbtion Spectrometry (AAS). The results revealed that the consumption of food crops grown on contaminated soils have significantly increased the concentrations of selected metals in the human hair. Pd and Cd concentrations in soils and food crops showed elevated levels above the WHO recommended limits. Pb, Cd, Cr, Cu, and Zn concentrations were significantly higher (p < 0.05) in male scalp hair samples collected from polluted area as compared to control area. In conclusion, consumers in the study area are exposed to high health risks associated with bioaccumulation of heavy metals through ingestion of heavy metals resulting from contamination of food crops grown in the study area and should be sensitized on the dangers of heavy metals on their health
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    Monitoring Exposure to Heavy Metals through Maize Consumption Using Human Hair among Male Adults in Eldoret Municipality, Kenya
    (Laikipia University College, Moi University, Daystar University, 2011-09-01) Ngure, Veronica; Simiyu, Gelas; Sitati, Noah; Kinuthia, Geoffrey K.; Shisia, Silvanus
    This paper reports on findings using hair as biomonitor marker for heavy metals (Pb, Cd, Cr and Cu) from geological source and exposure through regular maize consumption among selected male adults in Eldoret Municipality who had resided for five continous years. Concentration of Pb and Cu in anthropogenic pathways, while Cd and Cr reflected accumulation from the human activities. Usually higher concentration of heavy metals hair samples suggest longer term exposure. The estimated intake of Cd and Cr from maize in one zone associated with high concentration of the metals from geological source was appreciably above the respective recommended daily allowance (RDA), signifying possible health risks to humans. Significant correlations between Pb, Cd and Cu in hair and heavy metals from maize consumed suggested maize consumption as possible pathways of exposure of heavy metals in humans. Possible health risks from heavy metals were likely due to consumption of higher quantities of maize contaminated from geological and human activities