Occupational exposure to RF energy and SMFs in MRI units within Mangaung metropolitan region: a study protocol

Through exposure assessments, many studies in American and European countries have associated exposure to static magnetic fields with transient health effects, RF fields with thermal effects and time varying magnetic fields with motion induced effects amongst MRI staff. Literature on the long-term health implications is inconclusive. In South African, MRI staff are exposed to electromagnetic fields from MRI scanners and no exposure assessments have been conducted to quantify the levels. The aim of this study is to investigate the exposure levels of SM and RF fields in MRI units, and to assess the health effects resulting from exposure to SM and RF fields among MRI staff. This study is cross sectional and descriptive in nature. Measurements will be collected from two 1.5 Ts and one 3 T scanners in two academic hospitals. A THM1176 3-Axis hall magnetometer will be used to quantify the exposure levels of SMFs while TM-196 3 Axis RF Field strength meter will be used to measure RF fields. The SMF measurements will be taken per distance interim; 1 and 2 m away from the scanners when brain, cervical spine and extremities are scanned. RF fields’ measurements will be collected 1 m away from the scanners when patients are examined. Questionnaires will be administered on 42 MRI workers works with 1.5 and 3T MRI scanners. Ethical clearance and permission have been obtained. Data will be analyzed by SAS version 9.2. Categorical and numerical data will be calculated, chi-square test will also be used to test for differences between proportions. ANOVA will be used to compare the mean values and Mann-Whitney U-test will be used to compare median values. A significance level (α) of 0.05 will be used. The results from this study will be used to inform health policies related to MRI fields’ exposures in South Africa and to inform hierarchy of control measures that aims to reduce exposure-related effects. The occurrence of exposure-related effects among MRI staff has not yet been extensively studied in South Africa, and this study seeks to provide the exposure scenarios in the South African health care settings.