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Magnetic resonance imaging (MRI) staff is exposed to a complex mixture of electromagnetic fields from MRI units. Exposure to these fields results in the development of transient exposure-related symptoms. This study aimed to investigate the exposure levels of radiofrequency (RF) magnetic fields and static magnetic fields (SMFs) from 1.5 and 3.0 T MRI scanners in two public hospitals in the Mangaung Metropolitan region, South Africa. The exposure levels of SMFs and RF magnetic fields were measured using the THM1176 3-Axis hall magnetometer and TM-196 3 Axis RF field strength meter, respectively. Measurements were collected at a distance of 1 m (m) and 2 m from the gantry for SMFs when the brain, cervical spine and extremities were scanned. Measurements for RF magnetic fields were collected at a distance of 1 m with an average scan duration of six minutes. Friedman’s test was used to compared exposure mean values from two 1.5 T scanners, and Wilcoxon test with Bonferroni adjustment was used to identify where the difference between exist. The Shapiro–Wilk test was also used to test for normality between exposure levels in 1.5 and 3.0 T scanners. The measured peak values for SMFs from the 3.0 T scanner at hospital A were 1300 milliTesla (mT) and 726 mT from 1.5 T scanner in hospital B. The difference in terms of SMFs exposure levels was observed between two 1.5 T scanners at a distance of 2 m. The difference between 1.5 T scanners at 1 m was also observed during repeated measurements when brain, cervical spine and extremities scans were performed. Scanners’ configurations, magnet type, clinical setting and location were identified as factors that could influence different propagation of SMFs between scanners of the same nominal B0. The RF pulse design, sequence setting flip-angle and scans performed influenced the measured RF magnetic fields. Three scanners were complaint with occupational exposure guidelines stipulated by the ICNIRP; however, peak levels that exist at 1 m could be managed through adoption of occupational health and safety programs.

The aim of this study was to evaluate the exposure levels of ELF magnetic fields in the residential areas of Mangaung metropolitan municipality. Fifteen residential sites were randomly selected in Bloemfontein, nine in Botshabelo and six in Thaba Nchu areas of Mangaung. Measurements were collected at the distances of 3 m, 6 m and 9 m outside electrical substations, near every corner, using a Trifield meter model XE 100. Measurements were also collected from four different corners inside substations, near barrier screening and were referred to as a distance of 0 m (reference point). The results indicated a non-significant difference among 15 residential areas; BRE1 to BRE15 and six areas; TNRE1 to TRNE6. The exposure levels were significantly high in one residential area BORE1 (0.55 μT) as compared to other residential sites in Botshabelo (p < 0.001). The results obtained from the measurements also show a significant difference between the residential areas BORE4 and BORE8 (p < 0.01) as well as BORE4 and BORE9 (p < 0.006). The four distance interims also demonstrated a highly significant difference (p < 0.0001) when compared to one another. The t test showed a statistically significant difference for exposure levels recorded at 3 m, 6 m and 9 m in comparison to 0 m (p < 0.01). The exposure levels recorded at 3 m were also significantly different to those recorded at 6 m (p < 0.05) and 9 m (p < 0.01). The exposure levels measured at all distances are below the ICNIRP guidelines and the fields decrease rapidly with an increased distance from the source.

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The occupational health and safety of South African farm workers have been largely neglected because of the emphasis specifically put on the industrial environment. Although some studies have been done on the pesticide exposures of farm workers, the occupational health and safety of farm workers have not been studied as a whole and therefore there is no comprehensive occupational health and safety programme for farm workers. The aim of the study was to compile an applicable occupational health and safety programme for crop farm workers in the Mangaung local municipal district. Twenty-five farms in this region were selected and a list that included the different activities on the farms, the number of workers on each farm and the work hours of the workers was completed. The different health and safety hazards and associated risks were identified on each of the selected crop farms. A hazard identification risk assessment (HIRA) was compiled and completed to rate the different health and safety risks. The results of the study indicated that the main activities executed on the farms were preparation and ploughing of land, planting of crops, application of pesticides and the harvesting of crops. The HIRA indicated eleven "high" risks, seven "moderate" risks and only one "low" risk. An applicable overall occupational health and safety programme that included the abovementioned "high, moderate and low" risks was compiled. Individual occupational health and safety programmes for the control of 3. OCCUPATIONAL HEALTH AND SAFETY HAZARDS AND RISK ASSOCIATED WITH AGRICULTURAL WORK 4. HEALTH HAZARDS ASSOCIATED WITH AGRICULTURE 4.1 Chemical stresses associated with agriculture 4.2 Physical stresses associated with agriculture 5. SAFETY HAZARDS ASSOCIATED WITH AGRICULTURE 6. AGRICULTURAL EXPOSURE 7. HAZARD IDENTIFICATION RISK ASSESSMENT (HIRA) 8. OCCUPATIONAL HEALTH AND SAFETY PROGRAMME 9. REFERENCES CHAPTER 3 A WALK-THROUGH SURVEY OF CROP FARMS IN THE MANGAUNG MUNICIPAL DISTRICT 1. 4. DISCUSSION 5. CONCLUSION 6. REFERENCES CHAPTER 4 HAZARD IDENTIFICATION RISK ASSESSMENT ON CROP FARMS IN THE MANGAUNG MUNICIPAL DISTRICT CONCLUSION 7. REFERENCES CHAPTER 6 FEEDBACK FROM A FOCUS GROUP OF CROP FARMERS OF THE MANGAUNG MUNICIPAL DISTRICT ON THE SUGGESTED OCCUPATIONAL HEALTH AND SAFETY PROGRAMME 1. Diseases associated with agricultural work vary substantially from country to country. There are a range of factors which condition their existence: climate, fauna, population density, living conditions, eating habits, standards of hygiene, level of education, occupational training, working conditions, technological development and quality of and access to services (Forastieri, 2001). The major diseases occurring in agricultural work are infectious diseases such as those transmitted through contact with domestic or wild animals, respiratory infections, dermatosis, allergies, cancer and illnesses arising from working in the open air environment (Fenske, Hidy, Morris, Harrington and Keifer, 2002). Poisoning may With reference to the occupationa...