Objective
The purpose of this population-based case control study was to investigate a possible association between occupational exposure
to low frequency magnetic fields and the risk of low grade glioma (LGG) and high grade glioma (HGG).
Methods
The study population consisted of 414 histologically confirmed cases of glioma (LGG = 110, HGG = 304), first diagnosed between
July 1987 and December 1991, and 421 controls from Melbourne, Australia, matched by age, sex and postcode of residence. A
detailed occupational history was obtained for each subject. Exposure to low frequency magnetic fields was estimated using
three different methods: self-report, expert hygienist review and a job exposure matrix (JEM).
Results
Elevated but statistically non-significant risk estimates were found for all glioma and HGG when exposure was assessed by
the expert hygienist. The odds ratios (OR) for the highest exposed group of workers when assessed by the expert hygienist
were 1.4 (95% confidence interval, CI: 0.85–2.27) and 1.51 (95% CI: 0.90–2.53) for all glioma and HGG, respectively. There
were inverse associations for the self-reported and JEM exposures for both LGG and HGG but these may reflect limitations in
these exposure assessment methods.
Conclusions
Our results do not support a role for occupational exposure to low frequency magnetic fields in the development of either
LGG or HGG.
Keywords Low grade glioma - High grade glioma - Case–control study - Magnetic fields - Occupational exposure
This work was performed at the Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia