title: Occupational exposure of dentists to extremely-low-frequency magnetic field.
abstract: OBJECTIVE
  To compare occupational exposure to extremely-low-frequency magnetic field (ELF-MF) between dentists practicing in dental clinics and those employed in hospitals.
  
  
  METHODS
  Thirty-two dentists who worked at clinics (n=15) and 33 dentists employed at hospital dental departments (n=7) voluntarily provided their informed consent to participate in this measurement study. The study dentists were requested to wear an ELF-MF dosimeter for some 3 h at work to determine their personal exposure. Spot measurements taken at a number of locations in each dental office were used to indicate the work environment exposure level. Additionally, ELF-MF emitted from common dental equipment was also measured. All measurements were performed with EMDEX Lite meters.
  
  
  RESULTS
  The average environmental exposure to ELF-MF is higher in clinic dental offices than in hospital dental departments (0.55 vs. 0.15 µT, p=0.008). Personal dosimetry showed that on average, clinic dentists spent 35.71 and 19.39% of their time at exposures above 0.3 and 0.4 µT at work, respectively. The corresponding figures for hospital dentists were 19.61 and 13.92%. Additionally, ELF-MF was greater than 0.4 µT at 30 cm from all selected equipment, but the ELF-MF generally diminished as the distance from dental equipment increased. Uultraviolet air sterilization system produced 3 times as much ELF-MF as other dental equipment.
  
  
  CONCLUSIONS
  This study suggests the possibility of over-exposure of dentists to power frequency ELF-MF. Additionally, certain dental equipment may produce ELF-MF levels greater than 0.4 µT in areas where dentists usually work when treating patients.
authors.affiliation: Department of Public Health, College of Medicine, Fu-Jen Catholic University, Taiwan.
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Huang
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Lin
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Li
authors.forename: Ming-Fong
authors.initials: MF
authors.lastname: Chang
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Chen
mesh_terms: D003740:Dental Clinics; D003815:Dentists; D004574:Electromagnetic Fields; D006761:Hospitals; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*