Maccà I, Scapellato M L, Carrieri M, Pasqua di Bisceglie A, Saia B, Bartolucci G B
Department of Environmental Medicine and Public Health, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
Radiat Prot Dosimetry. 2008;128(2):180-90. doi: 10.1093/rpd/ncm309. Epub 2007 Jun 11.
To assess occupational exposure to electromagnetic fields, 11 microwave (MW), 4 short-wave diathermy and 15 magneto therapy devices were analysed in eight physiotherapy departments. Measurements taken at consoles and environmental mapping showed values above European Directive 2004/40/EC and ACGIH exposure limits at approximately 50 cm from MW applicators (2.45 GHz) and above the Directive magnetic field limit near the diathermy unit (27.12 MHz). Levels in front of MW therapy applicators decreased rapidly with distance and reduction in power; this may not always occur in work environments where nearby metal structures (chairs, couches, etc.) may reflect or perturb electromagnetic fields. Large differences in stray field intensities were found for various MW applicators. Measurements of power density strength around MW electrodes confirmed radiation fields between 30 degrees and 150 degrees , with a peak at 90 degrees , in front of the cylindrical applicator and maximum values between 30 degrees and 150 degrees over the whole range of 180 degrees for the rectangular parabolic applicator. Our results reveal that although most areas show substantially low levels of occupational exposure to electromagnetic fields in physiotherapy units, certain cases of over-occupational exposure limits do exist.
为评估职业性电磁场暴露情况,我们在八个理疗科室对11台微波(MW)设备、4台短波透热疗法设备和15台磁疗设备进行了分析。在控制台进行的测量以及环境测绘结果显示,在距离微波(2.45 GHz)施源器约50厘米处,测量值高于欧洲指令2004/40/EC和美国政府工业卫生学家会议(ACGIH)的暴露限值,并且在透热疗法设备(27.12 MHz)附近高于指令中的磁场限值。微波治疗施源器前方的水平随距离和功率降低而迅速下降;但在附近存在金属结构(椅子、长沙发等)可能反射或干扰电磁场的工作环境中,情况可能并非总是如此。不同的微波施源器产生的杂散场强度存在很大差异。对微波电极周围功率密度强度的测量证实,圆柱形施源器前方30度至150度之间存在辐射场,在90度处有峰值,而矩形抛物面施源器在180度的整个范围内,30度至150度之间有最大值。我们的结果表明,尽管大多数区域显示理疗科室的职业性电磁场暴露水平极低,但确实存在某些超过职业暴露限值的情况。