M.Tech. (Biomedical Technology) / TB continues to be one of the major causes of morbidity and mortality in developed and developing countries, (Mauch, 1993), despite the development of drugs and vaccines. Today, TB is one of the most serious health problems not only in South Africa, but worldwide. The transmission rate for TB for the population of Cape Town is 3% per year, while the transmission rate in gold mineworkers is estimated at 10% per year (Churchyard and Corbett, 2001). Tubercle bacilli have the ability of evading the immune system by entering a dormant phase while in the human host, and are able to reactivate at a later stage. Little is known about the mechanisms of this reactivation. TB remains a global emergency because of our lack of understanding of the details of its pathogenesis (Rook and Zumla, 2001). Since radioactive minerals are found in mines, it was postulated that radioactivity may be the reason for pulmonary cancers, a fact which is now well established. The biologic effects of radiation have been shown to produce irreparable deoxyribonucleic acid double-strand breaks or singlestrand breaks, or create structural changes by damaging the nucleus. Although no studies have shown toxic effects resulting from long-term, low-dose radiation exposure, risks are still assumed, (Herscovici and Sanders, 2000), and research concerning the mutagenic affects of lowdose radiation exposure is necessary. All the risk factors for pulmonary tuberculosis (PTB) in mineworkers are not known, although many have been identified, such as age and mining occupation. This study aimed to determine if long-term, low-dose exposure to ionizing radiation has an effect on the reactivation of dormant tubercle....
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:3663 |
| Date | 05 February 2014 |
| Creators | Houreld, Nicolette Nadene |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
Page generated in 0.0029 seconds