5 research outputs found

    gamma-ray mapping of environmental radioactivity at

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    In-situ and ex-situ measurements of environmental radioactivity were made on the iThemba LABS (iTL) grounds in South Africa. The MEDUSA and HPGe detector systems were used to make in-situ and ex-situ measurements, respectively. The MEDUSA was mounted ~0.5 m above the ground on a 4 × 4 vehicle to traverse [at ~2m∙s-1] the accessible portions of the iTL grounds. Spatial data (via a GPS receiver) were acquired every 1 s, and γ-ray spectra every 2 s. MEDUSA count rate maps were produced to show the spatial distribution of radioactivity on the grounds. The HPGe was used to measure the radioactivity in soil (and also in some grass) samples collected at particular spots on the iTL grounds. The sampled spots include six identified high activity spots (“hot spots”) and two “calibration spots”. The activity concentrations were determined for both the natural and anthropogenic radionuclides. The absorbed and effective doses (from external γ-ray irradiation) were also determined for the natural and anthropogenic radionuclides. The maximum effective dose to humans on the iTL grounds as a result of external exposure to natural and anthropogenic radionuclides was found to be well below the regulatory 1 mSv per year per member of public

    The contribution of trees and green spaces to household food security in eThekwini Metro, KwaZulu-Natal

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    One of the most significant issues faced by many low- and middle-income nations, including South Africa, is ensuring access to healthy, affordable, and sustainable food. South Africa is renowned worldwide for its rich biodiversity and a vast body of traditional knowledge among those who consume forest foods. However, despite ecological diversity, frequent barriers remain to getting diversified household diets. This study sought to investigate the contribution of trees and green spaces to household food security in eThekwini. A total of 280 households met the inclusion criteria and consented to participate in this study by responding to questionnaires. The collected data were analysed using descriptive statistics, the computation of the Household Food Insecurity Access Scale (HFIAS), and the Instrumental Variable Poisson model. The study’s results revealed that only 29% of the respondents were food secure, 36% were mildly food insecure, 27% were moderately food insecure, and 8% were severely food insecure. The Instrumental Variable Poisson model results revealed that cultivated green spaces, wealth index, gender, education level of the head of households, and grants had a negative correlation with household food insecurity. On the other hand, non-cultivated green spaces, local trees, age, marital status, number of dependents, and monthly income positively correlated with food insecurity. Given the existence of trees and green spaces in eThekwini, there is potential for food security solutions to be formed around both cultivated and uncultivated green spaces to promote sustainable access to food and nutritious diets in low-income households. Policy interventions should adopt an approach that encourages the incorporation of foods from both cultivated and uncultivated trees and green spaces in people’s diets

    Determination of soil, sand and ore primordial radionuclide concentrations by full-spectrum analyses of high-purity germanium detector spectra. Applied Radiation and Isotopes

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    Abstract The full-spectrum analysis (FSA) method was used to determine primordial activity concentrations (ACs) in soil, sand and ore samples, in conjunction with a HPGe detector. FSA involves the least-squares fitting of sample spectra by linear combinations of 238 U, 232 Th and 40 K standard spectra. The differences between the FSA results and those from traditional windows analyses (using regionsof-interest around selected photopeaks) are less than 10% for all samples except zircon ore, where FSA yielded an unphysical 40 K AC
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