Medical Officer of Health 2007 Technical Report

This report is an update to a 1999 Toronto Public Health (TPH) review summarizing research on exposure and health effects from radiofrequency (RF) emissions. The recent literature on RFs leads TPH to conclude that many of the uncertainties in the science identified in the 1999 review remain. Despite limitations in the body of research to date, the possibility of harmful health effects from RF exposures cannot be ruled out. 

Current safety standards for RF exposure are based on avoiding tissue damage from heating effects. The standards do not account for the effects that may occur at exposure levels that do not involve tissue heating. The public and some scientists have concerns about the potential for cumulative, whole-body exposure to RFs from their widespread use and presence in the environment. 

There is agreement that biological (i.e. non-thermal) effects from radiofrequencies are evident from research with animals, cell cultures and in humans. Continued research into these effects, including potential mechanisms of action and the significance of these effects for long-term human health, is warranted. 

Despite diverse views on whether exposure limits are adequately health protective, a number of jurisdictions have moved to adopt more stringent exposure standards. The Prudent Avoidance Policy previously endorsed by the Board of Health in 1999 requests that applicants who wish to install new antennas or modified antennas demonstrate that radio frequency (RF) exposures in areas where people normally spend time, (that is, workplaces, residences or areas where the public has unrestricted access) will be at least 100 times below those currently recommended by Health Canada’s limits for public exposure, known as Safety Code 6. 

The approach of the TPH Prudent Avoidance Policy has been applied successfully already to cell tower and wireless antenna sitings and has not placed undue burden on staff time or on the industry’s ability to comply. 

Health Canada has not revised its guidelines to address the concerns raised in 1999. This review indicates that, in the face of uncertain risks, prudent avoidance is still the best approach to minimize public exposure from the new and increasing number of RF sources in Toronto. The Medical Officer of Health recommends that the City continue with a prudent avoidance approach in siting new telecommunication towers and antennas in the City. Initial consultations can be used to collect data from cell phone carriers on predicted RF levels of proposed towers and antennas. This will allow the City to monitor the potential impact of proposed telecommunications facilities in Toronto and to encourage voluntary adoption of the Prudent Avoidance Policy.