Calibration and Performance Testing of Sodium Iodide, NaI (Tl), Detector at the Food and Environmental Laboratory of the Radiation Protection Institute of the Ghana Atomic Energy Commission

The performance testing of a newly acquired sodium iodide detector (NaI), (Tl)) at Ghana Atomic Energy Commission (GAEC) was investigated by carrying out energy and efficiency calibration on the detector, as well as validation of its calibration. The energy and efficiency calibrations were performed using mixed radionuclides 241 109 57 137 60 standard containing Am, Cd, Co, Cs and Co in the energy range of 60–1333 keV. The energy and efficiency calibration curves obtained compare well with what is available in the literature. Results of the validation of the calibration showed that there were no significance differences between the measured and the calculated activities of the standard radionuclides with activity ratios in the range of 0.90-0.98 and the corresponding percentage deviation in a range of 1.43–10.47%. The average MDA of 238U, 232Th, 40K and 137Cs from background counting rates were estimated to be 0.099 ± 0.055 Bq, 0.061 ± 0.037 Bq, 0.727 ± 0.300 Bq and 0.014 ± 0.006 Bq, respectively

Artificial and Natural Radioactivity Measurements and Radiation Dose Assessment in the Vicinity of Ghana Nuclear Research Reactor-1 (GHARR-1)

Radioactivity concentrations of <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs in soil samples and water sources around the Ghana Research Reactor-1 (GHARR-1) and the immediate surroundings have been measured using gamma spectrometry. The primary aim of the study was to establish baseline radioactivity levels in the environs of GHARR-1. The average activity concentration of <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs were 22.3 ± 1.12 Bq kg<sup>-1</sup>, 49.8 ± 1.60Bq kg-1, 99.60 ± 5.81 Bq kg<sup>-1</sup> and 1.48 ± 0.25 Bq kg<sup>-1</sup> for soil and 0.60 ± 0.11 Bq l<sup>-1</sup>, 2.13 ± 0.21 Bq l<sup>-1</sup>, 10.75 ± 0.84 Bq l<sup>-1</sup> and 0.47 ± 0.05 Bq l<sup>-1</sup>for the water, respectively. The <sup>226</sup>Ra and <sup>232</sup>Th concentrations compare quite well with world averages, whilst the <sup>40</sup>K concentration was lower than the world average. The levels of <sup>137</sup>Cs observed in the samples are within the range of ‘background’  concentrations. The estimated average annual effective doses from external exposure to soil and ingestion of water samples were calculated to be 0.06 mSv and 0.53 mSv, respectively. The estimated outdoor  external gamma dose rate measured in air ranged from 20-430 nGy h<sup>-1</sup> with an average value of 100 nGy h<sup>-1</sup>, which is higher than the world average value of 59 nGy h<sup>-1</sup>. In the case of water samples, the average value was higher than the guidance level of 0.1 mSv y<sup>-1</sup>, as recommended by the European Union and the World Health Organization

Energy price risk and the sustainability of demand side supply chains

AbstractEnergy is a critical input for production industries. As production becomes increasingly fragmented the management of inputs along the supply chain is a significant factor to stability and the competitiveness of the individual firm and the wider chain. Sustainable supply systems will require changes in how energy is managed particularly to ensure energy security. Rising and increasingly volatile industrial prices create technical price risks to individual firms and the supply chains they are within. A comparison is made between the management of metal and energy price volatility in the intermediate metal processing industry (IMP) in the West Midlands, UK. Results indicate significant variance between the management of price risks from the inputs due to the structure of the supply market, the political-economic context of energy as a carbon source and industrial conventions within the sector. Interdependence between economic actors in the demand-side supply chain can generate risk to the competitiveness of the firm and supply chain from the ability to transfer, or share, price changes in energy inputs through the supply chain. This is an important aspect of energy security in demand-side chains that threatens the sustainability of industrial activity

Diversification and agrarian change under environmental constraints in rural China: Evidence from a poor township of Beijing municipality

Working paper du GATE 2007-11This article illustrates the impact of changes related to market reforms and environmental policies on the economic structure in rural China by providing a comparative analysis of several villages in a poor township in Beijing municipality. Two main concomitant phenomena are affecting agricultural and non-agricultural choices in the studied area. First, the introduction of market mechanisms is encouraging local population to engage in new activities that are closer to local comparative advantages. Second, rural households are facing new constraints in the form of environmental protection measures, which have weakened traditional insurance channels provided by forest resources and cattle stock. Drawing on household-level survey data and interviews with village heads conducted in ten villages of Labagoumen township in December 2003, this article analyzes households decisions in response to market reforms and environmental constraints. We find large disparities both between villages and households in the diversification process and discuss the reasons of observed inertia in the region, most households still heavily relying on corn production

Natural radioactivity concentrations in beach sands from some tourist resorts., Research Journal of Environment and Earth Sciences

Abstract: Beaches along the coastlines in Ghana are important holiday destinations for tourists from many countries around the world. The radiological quality of sand from these beaches is very important to assess exposure of the public who use the beaches for recreational purposes and other activities. This study investigates the levels and hazards associated with the U-Th series and 40 K in beach sands from some renowned tourist resorts in the Greater Accra region of Ghana. Samples of beach sand from eleven beaches were analyzed using direct gamma-ray spectrometry. The total absorbed dose rate and the annual effective doses were calculated. The radiation hazards and risks associated with the use of the beach sand as construction material were also determined. The results show specific activities in the range 11.0-31.8 Bq/kg for 238 U, 0.5-1. U activity ratios calculated for the beaches is in the range of 0.032-0.053 with an average of 0.045±0.007 and that of the other radionuclides are close to unity, indicating only natural radionuclides were detected in the samples investigated. The results are within the values found in literature and show that the natural radionuclides in samples of the beach sand do not pose any significant risk to tourists and other holiday makers. Sand from the beaches is also safe for use as construction material, indicating the relevance in terms of the radiological quality of the beaches from both human and environmental health view points

Socio-economic characteristics and obesity in underdeveloped economies: does income really matter?

Available evidence suggests that overweight and obesity prevalence is increasing worldwide at an alarming rate in both developed and developing countries. This study focuses on the determinants of overweight in mothers and children, using a unique dataset collected in urban Accra, in Ghana. The findings show that mothers' education, employment status and ethnicity significantly exert influence on the generation of body weight. In particular, those who attained secondary and tertiary education had lower body mass indices and were much less likely to be overweight or obese, lending support to the notion that more educated women normally have better health knowledge and are more likely to consume healthy foods and also engage in physical exercises that help to control weight gain. Mother's education was also found to exert a negative and significant impact on the weight status of children. Furthermore, household expenditure was found to exert a positive and significant impact on the probability of a mother being overweight or obese, but no significant impact on the probability of a child being overweight.