During July 1976 a survey of the electromagnetic radiation emissions from the eN
Tower was made, to assess any possible health hazards to the general public and employees
working within the tower. Field intensity measurements were taken at all levels of occupancy
within the eN Tower, on the roofs of 5 downtown Toronto buildings, on 3 floors of the Bank
of Montreal Building, and at ground level of the Toronto Dominion Plaza. Measurements were
also taken along east, west and north radials from the eN Tower for distances up to 20 miles.
Unfortunately, at the time of the survey, not all the broadcast equipment had been
installed into the eN Tower and some of the stations were not operating at their fully licenced power levels. However, the survey results indicate that microwave radiation exposure levels are within currently accepted limits for both microwave radiation workers in the tower and for the general public. There does not appear to be a health hazard from the electromagnetic radiations emitted from the CN Tower.
Some interesting results from this document are as follows:
1. The highest reading (2000 microW/cm2), in FM transmitter rooms Level 5, was double the Canadian guideline (1000 microW/cm2) but was in a location that is not easily accessible and not frequently accessed. I wonder if this area has signs stating that levels are above guidelines to warn workers? Level 5 is located right beside the EdgeWalk platform.
2. The next highest reading (13 microW/cm2) was at a height of 477 m.
3. Power density readings are provided individually for each frequency on the space deck, sky pod roof, restaurant, upper and lower observation decks, outdoor terrace, and for the surrounding buildings. This doesn’t make any sense from an exposure perspective as people in these areas are exposed to all of the frequencies simultaneously. As a result this is a serious underestimation of the actual exposure and may account for difference in interpretation with Health and Welfare Canada stating this was safe and the US government recognizing that the cumulative frequencies are important and stating it was unsafe.
4. It would be worth repeating these measurements in the same locations to see how much they have increased before opening this rooftop amusement attraction to the public. Click here to learn more about safety procedures for workers that repair TV, radio and cell towers like the CN Tower.