This article is from the Static Electromagnetic Fields and Cancer FAQ, by John Moulder firstname.lastname@example.org and the Medical College of Wisconsin with numerous contributions by others.
Persons with occupational exposures to static fields include operators
of magnetic resonance imaging (MRI) units, personnel in specialized
physics and biomedical facilities (for example, those working with
particle accelerators), and workers involved in electrolytic processes
such as aluminum production. Some aluminum manufacturing workers are
reported to be exposed to fields of 5-15 mT for long periods of time,
with maximum exposures up to 60 mT [2,3]; but another study reports
average fields of only 2-4 mT . Workers in plants using electrolytic
cells are reported to be exposed to fields of 4-10 mT for long periods
of time, with maximum exposures up to 30 mT [5,6]. Individuals working
with particle accelerators are exposed to fields above 0.5 mT for long
periods of time, with exposures above 300 mT for many hours, and maximum
exposures of up to 2,000 mT .