A General Survey of Radon Concentration in Water from Rivers in Gauteng, South Africa Using a Solid-State ÃŽÂ±-DetectorMasevhe L1, Mavunda RD1,2* and Connell S1
- *Corresponding Author:
- Mavunda RD
Radiation Protection Training Centre (RPTC)
South African Nuclear Energy Corporation (NECSA)
Pelindaba, Britz, South Africa
E-mail: [email protected]
Received date: April 29, 2017; Accepted date: May 13, 2017; Published date: June 01, 2017
Citation: Masevhe L, Mavunda RD, Connell S (2017) A General Survey of Radon Concentration in Water from Rivers in Gauteng, South Africa Using a Solid-State α-Detector. J Environ Anal Toxicol 7:472. doi: 10.4172/2161-0525.1000472
Copyright: © 22017 Masevhe L, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In view of the geological setup and the long-standing mining history of the Gauteng Province, South Africa, it is expected that the mine dumps around the gold mines could contribute to a significant radium (226Ra) concentration in water in Gauteng Province. Radium decays to its daughter radioisotope radon (222Rn) which is a potential source of radiation exposure to the general public. Radon-222 easily escapes from surface of mineral grains and it becomes dissolved in ground water, rivers and dams which are ultimately used by the public. The research study was carried out to determine the effective dose (mSv) to the general public from radioactive (222Rn) in the water from 25 rivers and tributaries in the surrounding areas of Krugersdorp, Johannesburg, Pretoria and Vaal regions.
Water samples were collected from the rivers and analysed in the laboratory at Necsa in Pretoria. An α - spectrometry analysis using a solid-state alpha detector (RAD-7) was optimized to measure (222Rn) in the water by counting α - particles emitted by 218Po and 214Po in secular equilibrium with their parent, (222Rn).
The measured (222Rn) concentrations ranged from 1.4 × 10-1 to 3.56 Bq.l-1 with an average of 1.43 ± 4.3 × 10-1 Bq.l- 1. The average annual effective dose was found to be 4 × 10-3 μSv. The study showed that 222Ra concentration in river water from Gauteng is lower than international acceptable limits cited in the United States Environmental Protection Agency and the World Health Organisation of 1.11 × 10-1 Bq.l-1 and 1.0 × 10-2 Bq.l-1 respectively. The average effective dose is negligible (about 0.32%) as compared to the worldwide average annual effective dose from inhaled 222Rn of 1.26 mSv. Hence, the effective dose of 4 × 10-3 μSv does not pose any health threat to the general public that use water from Gauteng Rivers.