Levels of cobalt and silver in water sources in a mining area in Ghana

The study reported herein looked at the quality of drinking water sources (underground water and river water) from a mining community in Ghana. The water samples were treated in the laboratory by acid digestionand the concentration of silver and cobalt were analysed with Atomic Absorption Spectrophotometer. The results of the analysis indicated that all the water sources of Bogoso-Domase analyzed had levels of silver andcobalt above US-EPA limit 0.01 mg/L of silver and 0.079 mg/L of cobalt. The high mean concentration of cobalt in the underground and the river water sources may have been responsible for a deep blue colour changeof the water whenever it got into contact with tannin in plant, hence affecting the cooking of certain foodstuffs such as cassava and plantain. However, these metals are seldomly discussed when it comes to those metals of concern of mining pollution. This calls for extensive research into the lesser known metals in the mining environment which might equally pose health problems since some of the studies on their cancer effect onpeople are inconclusive. Keywords; Biomagnifies, photographic industry, Telluride, Argyria, Tannin, Dumase, Bogoso

Levels of arsenic in human hair as biomarkers of arsenic exposure in a mining community in Ghana

Arsenic levels were determined in human hair samples collected from a mining and non-mining community in Ghana. Hair samples were digested and analyzed using inductively coupled plasma atomic emission spectrometer (ICP–AES). Elevated levels of arsenic were found in the samples obtained from the mining community, the mean levels in the hair ranged from 0.0142–0.0515 μg/g, whereas arsenic was not detected in the hair samples from the non-mining community. The values obtained from the mining community were all below background levels set by the Agency for Toxic Substance and Disease Registry (ATSDR). The results therefore indicate that arsenic pollution may indeed be associated with mining, inducing human environmental exposure

Assessing the extraction efficiency of CaCl2 and rhizon extraction methods after the application of organic matter and CaCl2 as soil amendments to enhance the mobility of Cd and Zn

A pot experiment was conducted to study the extractability of cadmium and zinc by CaCl 2 and rhizon extraction methods after the application of organic matter and chloride as soil amendments. Two methods, Rhizon and CaCl 2 extraction methods were concurrently employed to study the effects of the various amendments on the mobility of Cd and Zn. Both CaCl 2 and Rhizon extraction methods generally extracted appreciable amounts of the heavy metals after the application of the amendments. However, the results from the experiment shows that the Rhizon samplers extracted higher concentrations of both Cd and Zn as compared to the CaCl 2 extraction method. The use of rhizon soil moisture sampler is also non destructive to the soil and makes it possible to ascertain levels of heavy metals at equilibrium in the soil solution without changing the compisition of the soil solution in the process of extracting it. Assessment of the soil pH in the soil samples and the Rhizon extracts after the application of the amendments showed no significant difference with the control. Comparatively, application of CaCl 2 had a significant mobilizing effect on the mobility of both Cd and Zn as a result of the combined effect of complexation of Cd and Zn by the chloride anion, and by the fact that Cd and Zn are referentially absorbed in cation exchange positions. Therefore the Ca 2+ ion can displace these metals into the soil solution

Lindane and propuxur residues in the top soils of some cocoa growing areas in five districts of the Central Region of Ghana

Lindane and propoxur residues in some topsoil samples from five cocoa growing districts in the Central Region of Ghana have been determined. Ten soil samples were taken randomly at a depth of 0-10 cm from pre-selected farms in each district. Some physical and chemical properties of the soils were determined. The pesticide residues were extracted from 50 g of topsoil by continuous Soxhlet extraction using a (1:1 v/v) acetone-chloroform mixture for six hours. Clean up of the extract was done by liquid-liquid partitioning and column chromatography using alumina and silica gel adsorbents. The pesticide residues were finally analysed by gas- chromatography using 63Ni electron capture detector (ECD) and flame ionization detector (FID) for lindane and propoxur, respectively. Lindane and propoxur pesticide residues were found to be present in all the soils to which these pesticides had already been applied. Generally, lindane residues occurred in greater amounts than propoxur. The concentrations of lindane ranged from 2.1 to 15.4 mg kg-1 and propoxur from 1.71 to 7.95 mg kg-1. Both the extracted lindane and propoxur residues correlated negatively with pH, cation exchange capacity, moisture content, and organic carbon. Propoxur correlated positively with the amount of clay but there was no significant correlation between the amount of clay and the extracted lindane concentration.KEY WORDS: Lindane, Propoxur, Soil, Pesticide monitoringBull. Chem. Soc. Ethiop. 2006, 20(2), 193-199

Comparative Studies of the Physicochemical Properties and Heavy Metals adsorption Capacity of Chemical Activated Carbon from Palm Kernel, Coconut and Groundnut Shells

Comparative studies of the physicochemical properties of chemical activated carbon from palm kernel (PKS), coconut (CNS) and groundnut (GNS) shells were investigated. The properties investigated were pH, moisture content, specific gravity, BET surface area, pore volume, porosity, ash content and metal ions present. From the results obtained, the chemical activated carbon prepared from palm kernel, coconut and groundnut shells shows good physicochemical properties and adsorption capacity. However coconut shell with BET surface area 1177.520 (m2/g), potassium content of 179.33ppm and pH 7.5, having a better advantage to be used as organic fertilizer compare to groundnut shell with BET surface area 950.069 (m2/g), potassium content of 140.00ppm & pH 8.4 and palm kernel shell with BET surface area 717.142(m2/g), potassium content of 128.00ppm and pH 8.7 respectively in that order. Also, coconut shell with pore diameter of 2.840e+00, specific gravity of 1.42 & moisture content of 19.7% makes it a prefer option compare to groundnut shell with pore diameter of 2.920e+00, specific gravity of 148 & moisture content of 19.8% and palm kernel shell with pore diameter of 2.840e+00, specific gravity of 1.61 and moisture content of 20.4% respectivelyKeywords: Chemical activated carbons, physicochemical properties, BET surface area and heavy metal

Increasing Pesticide Use and Knowledge of the Health Effects of Endocrine Disrupting Chemicals in the Environment: A Study of Three Communities in Ghana

Population growth and urbanisation are contributing to the growth of the use of pesticides in Africa. However, poor understanding of the health and environmental effects of these chemicals represents a significant risk to both human health and ecosystems. Knowledge of health effects of pesticide use and endocrine disrupting chemicals (EDCs) was assessed using 300 respondents in three communities of Ghana. The data were fitted to bivariate and multivariate ordinary least squares regression models. About 76 per cent of the respondents used pesticides while 82 per cent had no knowledge of human diseases associated with pesticide use and EDCs. At the bivariate level, individuals who used pesticides had less knowledge of health effects of EDCs and pesticide use compared to their counterparts who did not use pesticides. Urban residents had more knowledge compared to rural dwellers and this robust relationship persisted at the multivariate level. Females of all ages had more knowledge of pesticides and EDCs’ effects than their male conterparts. Formal and informal education is required to improve knowledge on appropriate chemical use

Heavy metal content and health risk assessment of commonly patronized herbal medicinal preparations from the Kumasi metropolis of Ghana

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