Dr. Magda Havas, PhD Environmental Studies Research Papers

Magnetic Fields on Public Transit

Posted on October 8, 2009

Havas, M., S. Shum, and R. Dhalla. 2004. Passenger Exposure to Magnetic Fields on Go Trains and on buses, streetcars, and subways run by the Toronto Transit Commission, Toronto, Canada. Biological Effects of EMFs, 3rd International Workshop, Kos, Greece 4-8 October, 2004, pp: 1065-1071.


Magnetic flux density was measured in the passenger compartment of buses, streetcars, subways and GO-trains that move millions of commuters daily in the Greater Toronto Area. The highest magnetic fields were found in subways (mean 30 mG, range 3 to 100 mG), followed by streetcars (mean 30 mG, range 2 to 100 mG), buses (mean 11 mG, range 1 to 50 mG) and the GO-train (mean 2 mG, range 1.2 to 2.8 mG). The magnetic field increased with acceleration and deceleration and varied with seat location and this was most obvious in subways and streetcars. All seats on subways, 98% of seats in streetcars, 85% in buses, and 38% on the GO train exceeded 2 mG, the magnetic field associated with childhood leukemia. The magnetic fields in the Toronto public transit system are higher than in most residential and occupational settings and are cause for concern considering that several studies have reported increased incidence of breast cancer, brain tumors, and leukemia among transit employees. Commuters with electrical sensitivity may have difficulty using some forms of public transit and as many as 2% of the 1.4 million daily revenue passengers in the Greater Toronto Area may be electrically sensitive. If the magnetic fields obtained in this study are representative of the transit system, then steps need to be taken to reduce magnetic field exposure of both commuters and transit employees.

Magnetic Exposure of Passengers riding on Public Transit in Toronto

Magnetic Exposure of Passengers riding on Public Transit in Toronto

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