Assessment of exposure to magnetic fields in occupational settings.
OBJECTIVE
It is important to have data about occupational magnetic field intensity to consider the contribution of occupational magnetic field exposure on the human body. We conducted research on exposure to occupational magnetic fields and tried to qualify data on the distribution of magnetic field' intensity in certain general working environments with individual measurements.


METHODS
We performed sample research on the exposure to low-frequency magnetic fields of workers in certain occupations and in the working environment. We also assessed the relationship between working environmental magnetic field distribution and individual exposure.


RESULTS
Some occupations were found to be exposed to high magnetic fields. We observed that some workspaces, such as the transformer substation, generally had a uniform and high magnetic field measurement but employees were exposed to a lower intensity. We also found that welders were exposed to high magnetic fields at about 600 microT in a very short time but with a geometrical value of 0.08 microT.


CONCLUSIONS
The determination of administrative levels and control levels, not only of the time weighted average of threshold limits or short term exposure limits, but also ceiling limits should be considered. More systematic research is necessary to determine variables such as operating conditions, measuring position, and frequency bands. Also, further studies will be needed to make a job-exposure matrix for the magnetic fields for each occupation type and to combine it with exposure in non-occupational settings such as commuting and ordinary life situations to explore the causal relationship between exposure to magnetic fields and disease.
Sakurazawa
Hirofumi
H
Department of Environmental Health, School of Medicine, Fukui Medical University, Japan.
Iwasaki
Akio
A
Higashi
Toshiaki
T
Nakayama
Takeo
T
Kusaka
Yukinori
Y
D004574:Electromagnetic Fields; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*; D009790:Occupations