Exposure to static and time-varying magnetic fields from working in the static magnetic stray fields of MRI scanners: a comprehensive survey in the Netherlands

Schaap, Kristel, Christopher-De Vries, Yvette, Crozier, Stuart, De Vocht, Frank and Kromhout, Hans (2014) Exposure to static and time-varying magnetic fields from working in the static magnetic stray fields of MRI scanners: a comprehensive survey in the Netherlands. Annals of Occupational Hygiene, 58 9: 1094-1110. doi:10.1093/annhyg/meu057


Author Schaap, Kristel
Christopher-De Vries, Yvette
Crozier, Stuart
De Vocht, Frank
Kromhout, Hans
Title Exposure to static and time-varying magnetic fields from working in the static magnetic stray fields of MRI scanners: a comprehensive survey in the Netherlands
Journal name Annals of Occupational Hygiene   Check publisher's open access policy
ISSN 1475-3162
0003-4878
Publication date 2014-11-01
Year available 2014
Sub-type Article (original research)
DOI 10.1093/annhyg/meu057
Open Access Status Not yet assessed
Volume 58
Issue 9
Start page 1094
End page 1110
Total pages 17
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Language eng
Abstract Clinical and research staff who work around magnetic resonance imaging (MRI) scanners are exposed to the static magnetic stray fields of these scanners. Although the past decade has seen strong developments in the assessment of occupational exposure to electromagnetic fields from MRI scanners, there is insufficient insight into the exposure variability that characterizes routine MRI work practice. However, this is an essential component of risk assessment and epidemiological studies. This paper describes the results of a measurement survey of shift-based personal exposure to static magnetic fields (SMF) (B) and motion-induced time-varying magnetic fields (dB/dt) among workers at 15 MRI facilities in the Netherlands. With the use of portable magnetic field dosimeters, >400 full-shift and partial shift exposure measurements were collected among various jobs involved in clinical and research MRI. Various full-shift exposure metrics for B and motion-induced dB/dt exposure were calculated from the measurements, including instantaneous peak exposure and time-weighted average (TWA) exposures. We found strong correlations between levels of static (B) and time-varying (dB/dt) exposure (r = 0.88–0.92) and between different metrics (i.e. peak exposure, TWA exposure) to express full-shift exposure (r = 0.69–0.78). On average, participants were exposed to MRI-related SMFs during only 3.7% of their work shift. Average and peak B and dB/dt exposure levels during the work inside the MRI scanner room were highest among technical staff, research staff, and radiographers. Average and peak B exposure levels were lowest among cleaners, while dB/dt levels were lowest among anaesthesiology staff. Although modest exposure variability between workplaces and occupations was observed, variation between individuals of the same occupation was substantial, especially among research staff. This relatively large variability between workers with the same job suggests that exposure classification based solely on job title may not be an optimal grouping strategy for epidemiological purposes.
Keyword EMF
Exposure assessment
Exposure variability
MRI
MRI staff
Occupational exposure
Static magnetic fields
Time-varying magnetic fields
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
School of Information Technology and Electrical Engineering Publications
 
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