Assessment of heavy metal pollution in drinking water due to mining and smelting activities in Ajaokuta, Nigeria

Mining and smelting activities are the main causes for the increasing pollution of heavy metals from water sources. The toxicity of these heavy metals from the mining, milling and smelting companies can cause harmful and even lethal effects on the human health. The objective of this study was to investigate the level of As, Cr, Zn, Mg, Fe, Pb, Cd, Cu, Ag and Mn in well and tap water and assess the degree of pollution in the study area. Atomic Absorption Spectrometry investigation was carried out on 60 samples of water (Well and Tap) collected within and outside the mining and smelting area of Ajaokuta to determine the extent of these heavy metals contamination in their drinking water. The data of heavy metal concentrations reveal that the area has been slightly contaminated with the heavy metals, with As and Cr having the highest level of contamination. Correlation analysis between the selected heavy metals was conducted to further investigate the relationship between the metals. The result shows that these selected metals have common pollution sources related to the mining and smelting activities in the area.Keywords: Heavy metals, atomic absorption spectrometry (AAS), smelting, pollution, well wate

Natural Radioactivity and Radiological Impact Assessment of Soil, Food and Water around Iron and Steel Smelting Area in Fashina Village, Ile-Ife, Osun State, Nigeria

This study assessed the natural radioactivity and radiological health impact of thirty-eight (38) samples of soil, food and water in Fashina village, Ile-Ife, Osun State, Nigeria using portable survey meter with a Global Positioning System (GPS) and well-calibrated NaI(Tl) detector system The mean exposure rates in the study area were 0.14 μSv hr-1 and 0.12 μSv hr-1 in soil/food and water samples respectively. The mean radioactivity content obtained for 238U, 232Th and 40K were 12.14 ± 4.17Bq kg-1, 23.23 ± 7.67 Bq kg-1 and 270.14 ± 61.79Bq kg-1 respectively in soil samples and 8.56 ± 2.80Bq kg-1, 13.17 ± 4.48Bq kg-1 and 89.41 ± 24.15Bq L-1 respectively for 238U, 232Th and 40K in water samples. The mean values of 30.91, 15.64 and 12.47 nGy h-1 were obtained for the absorbed dose rate in soil, food and water, respectively, while 37.90,  178.79 and 1085.23 μSv y-1 were obtained for the Annual Effective Doses (AED). Similarly, the Radium equivalent (Raeq) were 66.16 Bq kg-1, 34.28Bq kg-1 and 27.31BqL-1, in soil, food and water, respectively. The external and internal radiation hazard indices were 0.18 and 0.21, 0.09 and 0.12, 0.07 and 0.09, respectively for soil, food and water. The values obtained for the Excess Lifetime Cancer Risk (ELCR) in (x 10-3) were also 0.13, 0.63 and 3.80 for the soil, food and water samples, respectively. It was found that the values of some exposure rate, radioactivity contents and radiological impact parameters in the study area which were higher than those of the control area and the world average values poses a serious health risk to the environment and its inhabitants.Keywords: Radioactivity, Scrap Metal, Gamma Spectrometry, Radiological Impact Paramete

Radiological Impacts of Natural Radioactivity in Locally Produced Tobacco Products in Ibadan, Oyo State, Nigeria

Radionuclides are found naturally in air, water and soil. They are even found in vegetation, consumer products and in human body. Everyone on the planet is exposed to some background level of ionizing radiation through external exposures that occurs as a result of irradiation, and internal exposures that occurs as a result of ingestion and inhalation. Studies have shown that tobacco contains minute quantities of radioisotopes from uranium and thorium-decay series which are radioactive and carcinogenic. Tobacco product increases both external and internal exposure due to these radioisotopes. In fact, tobacco products have been considered to be one of the most significant causes of lung cancer. Owing to the large-scale consumption of tobacco in Nigeria at the present time, locally produced tobacco products in Nigeria were collected from the market and the naturally-occurring 238U and 232Th decay series, as well as non-series decay 40K in these products were measured using γ-ray spectrometer. The radiological impacts of the radionuclides in these products were assessed from their specific activities. The average values of the absorbed dose rate were 19.72 and 17.59 nGy h-1 for snuff and cigarette products respectively. The average values of the effective doses due to daily inhalation of smoke by consumers from one wrap of snuff and one stick of cigarette products is 592.32 and 66.62 μSv yr-1 respectively. Similarly, the values of the radium equivalent activity index for snuff and cigarette samples were 40.95 and 38.95 Bq kg-1 respectively. Also the external radiation hazard index were 0.12 and 0.11 for snuff and cigarette samples respectively while the internal radiation hazard index were 0.17 and 0.15 for the two samples respectively. The average excess lifetime cancer risk (x 10-3) values for daily inhalation of smoke from one wrap of snuff and one (1) stick of cigarette were 2.07 and 0.23 x 10-3 respectively. The estimated values of some of these parameters were found to be lower than the recommended limit by UNSCEAR (2000). However, the effective dose poses a serious health risk to addicted consumers of the product when three (3) or more wraps of snuff and one (1) or more packs of cigarette products are consumed daily. The mean excess lifetime cancer risks values estimated were also much higher than the recommended limits by UNSCEAR (2000). This then makes the risk of suffering cancer and other radiation injuries to be high.Keywords: Radiological impacts, Tobacco, Cigarette, Snuff, Cancer, Radiation injury, Nigeria

Radioactivity and hydrocarbon generation potential of sediments, Gongola Basin, Nigeria

Samples taken from Well Kolmani-1 in the Gongola Basin in the Upper Benue Trough of Nigeria were studied to estimate the radiogenic heat generated and to analyze the possible impact of radiogenic heat on hydrocarbon generation potential of the sediments. Thirty-eight samples taken from the different formations at intervals of 73.2 m including sand, shale, coaly shale, sandy shale, and shaly sand were analyzed for 40K, 238U, and 232Th using the well calibrated NaI (Tl) Gamma Ray detector System. The results showed that the activity concentrations of the radio-nuclides varied significantly within the sediments. The 40K concentrations were the highest. The radiogenic heat produced ranges widely from 228.44 pW/kg to 1 412.82 pW/kg. In Well Kolmani-1, sands and sandy shale are low heat production sediments, while the shale, coaly shale and silty sands are medium heat production sediments, the potential source rock (shale and coaly shale) medium in heat production (750 pW/kg to 1 500 pW/kg), can produce liquid and gaseous hydrocarbons. It is estimated that the radiogenic heat from the sediments contributed about 10.9% to 20.9% to the total surface heat flux in the basin. Therefore, the radiogenic heat generated by the sediments contributed significantly to the total surface heat flux, and should be taken into consideration in the simulation of basin thermal evolution. Key words: radioactivity, radiogenic heat, hydrocarbon generation potential, Gongola Basi

Assessment of Heavy Metal Pollution in Drinking Water Due to Mining and Smelting Activities in Ajaokuta, Nigeria

Mining and smelting activities are the main causes for the increasing pollution of heavy metals from water sources. The toxicity of these heavy metals from the mining, milling and smelting companies can cause harmful and even lethal effects on the human health. The objective of this study was to investigate the level of As, Cr, Zn, Mg, Fe, Pb, Cd, Cu, Ag and Mn in well and tap water and assess the degree of pollution in the study area. Atomic Absorption Spectrometry investigation was carried out on 60 samples of water (Well and Tap) collected within and outside the mining and smelting area of Ajaokuta to determine the extent of these heavy metals contamination in their drinking water. The data of heavy metal concentrations reveal that the area has been slightly contaminated with the heavy metals, with As and Cr having the highest level of contamination. Correlation analysis between the selected heavy metals was conducted to further investigate the relationship between the metals. The result shows that these selected metals have common pollution sources related to the mining and smelting activities in the area

Determination of selected heavy metals and human health risk assessment in fishes from Kiri Dam and River Gongola, Northeastern Nigeria

The concentrations of Pb, Cd, Cr, Fe and As in the Catfish and Tilapia from Kiri Dam and River Gongola, Northeastern Nigeria were analyzed using Atomic Absorption Spectrometer (AAS). The result reveals that these selected heavy metals are higher in Catfish than Tilapia irrespective of the location. Assessment of the health risks due to consumption of these fishes suggests that both fishermen and the general populace are not subjected to a significant potential health risk. The results of this study regarding metal contents in fishes from the study areas also suggest that theconsumption of catfish and tilapia from the study area is not free of risks. And that the complex THQ and TTHQ parameters used in health risk assessment of heavy metals provides a better image than using only a simple parameter like the content of the metals in the samples