Playing Near Power Lines: Cause for Concern

1. Playing Near Power Lines: Cause for Concern? Toronto Public Health November 2005

2. Overview Introduction Policy Process Background Literature Review Discussion of Field Sampling Context Challenges in Developing a Policy Potential Approaches to EMF Policy

3. Introduction Municipalities were requested by the province to identify interests in the secondary use of hydro corridors Toronto Public Health was requested to provide a health perspective on the secondary use of hydro corridors in Toronto

4. Policy Process Review of literature Consultation Field sampling of magnetic fields Preparation of draft policy Further consultation!

5. Background �EMF� is used to refer to electric and magnetic fields at extremely low frequencies Focus on 60 Hz fields produced by the generation, transmission and use of electricity Toronto currently has 243 hectares (600 acres) of park space in hydro corridors Opportunity to expand park space by a similar area

6. Literature Review Magnetic fields a �possible� human carcinogen based on childhood leukemia studies (IARC) Weaker evidence of other potential health effects Review of international policies and standards MF levels reported for hydro corridors Community benefits derived from park use

7. EMF Standards and Policies Standards ICNIRP: 833 mG (based on acute effects) Different approaches taken in Switzerland, Italy, Sweden, California Swiss standard (10 mG for sensitive sites most precautionary) Prudent Avoidance Policy in the former City of Toronto (1993) In 1993, the former City of Toronto adopted a policy of prudent avoidance, which advocated limiting exposure to electric and magnetic fields in public spaces where practical and feasible at little or not cost. The policy used a case-by-case approach in determining how prudent avoidance should be implemented. Specific references were made in the policy with respect to requesting that utilities use technology to mitigate magnetic fields, locating playgrounds, day care centres and schools away from power lines and transformers, and ensuring that new residential units are as far away from the power lines as possible and at least as far as other residences in the area. No distances or acceptable levels of magnetic fields were specified In 1993, the former City of Toronto adopted a policy of prudent avoidance, which advocated limiting exposure to electric and magnetic fields in public spaces where practical and feasible at little or not cost. The policy used a case-by-case approach in determining how prudent avoidance should be implemented. Specific references were made in the policy with respect to requesting that utilities use technology to mitigate magnetic fields, locating playgrounds, day care centres and schools away from power lines and transformers, and ensuring that new residential units are as far away from the power lines as possible and at least as far as other residences in the area. No distances or acceptable levels of magnetic fields were specified

8. Field Sampling Objectives To obtain an indication of the environmental levels of extremely low frequency (ELF) magnetic fields in hydro corridors To gather evidence to inform a policy on the secondary uses of hydro corridors

9. 9 Development of Sampling Protocol Literature best practices in magnetic field sampling Consultations Industry professionals in North America University Researchers Health Canada

10. Field Sampling Site Selection 18 Hydro Corridor and 18 Non-Hydro Corridor Park Sites Selection Criteria Geographic distribution Park use (e.g. sports fields, community gardens, playgrounds, trails) Non-hydro corridor sites were selected with respect to proximity to hydro corridor sites

11. ResultsComparison of HC and NHC Parks Hydro Corridor Park Sites 18 sampling sites Range: 0.6 to 102 mG Median: 22.8 mG Measurements above 10 mG (Swiss guideline) observed at 17/18 sites Non-Hydro Corridor Park Sites 18 sampling sites Range: BDL to 16 mG Median: 0.4 mG all measurements above 2 mG were taken directly under distribution lines

12. Results: Summary Magnetic fields are higher in hydro corridor sites than in non-hydro corridor park sites Much variation in the levels of magnetic fields between hydro corridor sites Substantial variation within each hydro corridor site levels are typically highest directly under the lines and decrease with increasing distance from the lines Minimal variation both between and within non-hydro corridor sites Time of day variations are present

13. Limitations Spot measurements daily, time of day, seasonal variation fluctuation of readings Focus on park settings Environmental levels not Exposure

14. Context Magnetic fields are considered a �possible human carcinogen� based on studies revealing an excess risk of childhood leukemia associated with exposure to ELF magnetic fields at levels above 3 mG and 4 mG. Levels above 3 mG were observed in all hydro corridor sites and elsewhere in the urban environment 833 mG ICNIRP standard

15. Context (cont.) Health benefits of secondary uses of hydro corridors Access to affordable physical activity Food security Safe communities

16. EMFs are in most urban settings (home, work, street level) Limitations to health studies Mode of action has not been established Studies reflective of exposure are difficult to design What levels may be of most concern? Short term vs. Long-term exposure Challenges in Developing EMF Policy

17. Further Challenges To reflect the health findings, some argue for a standard of 2 mG Median measurement in hydro corridor was 22.8 mG Levels in homes at times exceed 2 mG Hypersensitivity

18. Further Challenges Varying international approaches to EMFs Existing parkland in hydro corridors � 243 hectares (600 acres) Parks in hydro corridors offer the only park space in some �at-risk� parts of the City City has identified the need for more park and recreational space Limited opportunities to increase parkland in the City of Toronto Existing uses of land adjacent to hydro corridors (e.g. housing)

19. Prudent Avoidance Encouraging the adoption of individual or societal actions to avoid unnecessary exposures to magnetic fields that entail little or no cost. How might this apply to the secondary uses of hydro corridors?

20. Potential Policy Approaches Status quo No public uses within hydro corridors Posting signs advising users of potential risk Low-cost actions to minimize exposure Move existing facilities Require that MF measurements are taken when new recreational sites are planned in hydro corridors Place recreational facilities in areas where lower magnetic fields are expected based on measurements

21. Potential Policy Approaches(cont.) Consider estimated exposure time of the proposed secondary use when contemplating the development of recreational spaces in hydro corridors Request that hydro utility companies take measures to reduce magnetic fields where it can be done safely

22. Next Steps Further consultation Board of Health (2006)

23. Melanie LalaniResearch Consultant Environmental Protection OfficeToronto Public Healthe-mail: mlalani@toronto.caPhone: (416) 338-8095