Study type: Epidemiological study (observational study)

Cardiovascular mortality and exposure to extremely low frequency magnetic fields: a cohort study of Swiss railway workers. epidem.

Published in: Environ Health 2008; 7 (1): 35-1-35-7

Aim of study (acc. to author)

A cohort study was conducted in Switzerland to examine the cardiovascular mortality and the occupational exposure to intermittent 16.7 Hz magnetic fields.

Further details

Exposure to magnetic fields was determined by measurement and modeling for each occupational group. Cumulative exposure for each individual was achieved by adding up annual workplace specific exposures during his work life.

Endpoint/type of risk estimation

Type of risk estimation: (unspecified)



Exposure groups

Group Description
Group 1 station master: average exposure in 1980: 0.7 µT
Group 2 train attendant: average exposure in 1980: 1.8 µT
Group 3 shunting yard engineer: average exposure in 1980: 5.5 µT
Group 4 train driver: average exposure in 1980: 21.4 µT
Group 5 station master: average exposure in 2000: 1.0 µT
Group 6 train attendant: average exposure in 2000: 4.2 µT
Group 7 shunting yard engineer: average exposure in 2000: 6.0 µT
Group 8 train driver: average exposure in 2000: 21.0 µT
Group 9 station master: median cumulative lifetime expsoure: 5.7 µT-years
Group 10 train attendant: median cumulative lifetime expsoure: 13.3 µT-years
Group 11 shunting yard engineer: median cumulative lifetime expsoure: 42.1 µT-years
Group 12 train driver: median cumulative lifetime expsoure: 120.5 µT-years


Study size

Type Value
Total 20,141

follow-up of 464,129 person-years

Statistical analysis method: ( adjustment: )

Conclusion (acc. to author)

5,413 deaths were observed in the cohort, 3,594 deaths were attributed to cardiovascular diseases. The hazard ratios for all cardiovascular mortality and for the subgroups were not elevated in the separate analysis for train drivers, shunting yard engineers, train attendants or station masters. For cumulative exposure the hazard ratio was not increased.
The results provide evidence against an association between long-term exposure to 16.7 Hz magnetic fields and cardiovascular mortality.

Study funded by

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