title: Exposure classification of MRI workers in epidemiological studies.
abstract: We estimate that there are about 100,000 workers from different disciplines, such as radiographers, nurses, anesthetists, technicians, engineers, etc., who can be exposed to substantial electromagnetic fields (compared to normal background levels) around magnetic resonance imaging (MRI) scanners. There is a need for well-designed epidemiological studies of MRI workers but since the exposure from MRI equipment is a very complex mixture of static magnetic fields, switched gradient magnetic fields, and radiofrequency electromagnetic fields (RF EMF), it is necessary to discuss how to assess the exposure in epidemiological studies. As an alternative to the use of job title as a proxy of exposure, we propose an exposure categorization for the different professions working with MRI equipment. Specifically, we propose defining exposure in three categories, depending on whether people are exposed to only the static field, to the static plus switched gradient fields or to the static plus switched gradient plus RF fields, as a basis for exposure assessment in epidemiological studies.
authors.affiliation: Department of Radiation Sciences, Umeå University, Umeå, Sweden. kjell.hansson.mild@radfys.umu.se
authors.forename: Kjell
authors.initials: K
authors.lastname: Hansson Mild
authors.forename: Jeff
authors.initials: J
authors.lastname: Hand
authors.forename: Maila
authors.initials: M
authors.lastname: Hietanen
authors.forename: Penny
authors.initials: P
authors.lastname: Gowland
authors.forename: Jolanta
authors.initials: J
authors.lastname: Karpowicz
authors.forename: Stephen
authors.initials: S
authors.lastname: Keevil
authors.forename: Isabelle
authors.initials: I
authors.lastname: Lagroye
authors.forename: Eric
authors.initials: E
authors.lastname: van Rongen
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Scarfi
authors.forename: Jonna
authors.initials: J
authors.lastname: Wilén
mesh_terms: D000818:Animals; D016021:Epidemiologic Studies; D006801:Humans; D060526:Magnetic Fields / Q000009:adverse effects; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D016273:Occupational Exposure / Q000032:analysis / Q000145:classification*; D011829:Radiation Dosage; D011846:Radio Waves / Q000009:adverse effects