1. Ibrahim Omar Habiballah KFUPM May 28, 2008 1

2.  Objectives  Review of the Standards & Literature  Study Data  Calculation of External Fields  Compliance with the Standards and Guidelines  Calculation of Internal Induced Current Density and Electric Field  Compliance with the Standards and Guidelines  Conclusions 2

3.  To compute external EF & MF and the internal electric fields and current densities induced in a realistic, anatomically derived human body model for people working under 132 kV SEC T.L. 3

4.  IEEE Std C95.6, “IEEE Standard for Safety Levels with Respect to Human Exposure to Electromagnetic Fields, 0–3 kHz”, 2002.  International Commission on Non-Ionizing Radiation Protection (ICNIRP), “Guidelines limiting exposure to time-varying electric, magnetic, and EM fields (up to 300 GHz)”, 1998. 4

5.  National Radiological Protection Board, UK (NRPB) “ELF Electromagnetic fields and the risk of cancer”. Documents of the NRPB. Vol. 12, No 1, 2001.  Publication of American Conference of Governmental Industrial Hygienists (ACGIH) “Radio-Frequency and ELF Electromagnetic Energies: A Handbook for Health Professionals” 1995. 5

6. 6

7. 7

8. 8

9. 9

10. 10

11. 11 Double circuit line: Nominal voltage 132 kV, Power ratings 293 MVA. 1 2,3 4 9 6510117,8

12. 12  Calculation of External Electric Field Methodology: Charge Simulation Method Software:EMF Workstation Provider: EPRI  Calculation of External Magnetic Field Methodology: Biot Savart Law Software: EMF Workstation Provider: EPRI

13. 13 Calculation of External Field Based on Charge Simulation Method Centre Line Lateral Distance Minimum Clearance = 30 ft Maximum Clearance = 60 ft Lateral Distance Example of Electric Field Profile

14. 14 Centre Line Lateral Distance Minimum Clearance = 30 ft Maximum Clearance = 60 ft Calculation of External Field Based on Charge Simulation Method Example of Electric Field Profile in 3-D Lateral Distance

15. 15 Calculation of External Field Based on Biot Savart Law Lateral Distance Example of Magnetic Field Profile Centre Line Lateral Distance Minimum Clearance = 30 ft Maximum Clearance = 60 ft

16. 16 Calculation of External Field Based on Biot Savart Law Example of Magnetic Field Profile in 3-D Centre Line Lateral Distance Minimum Clearance = 30 ft Maximum Clearance = 60 ft

17. 17

18. 18 1 2,3 4 9 6510117,8

19. 19

20. 20 1 2,3 4 9 6510117,8 4.95 kV/m 521 mG 6.06 kV/m 621 mG 6.48 kV/m 664 mG 0.165 kV/m 21.4 mG 0.745 kV/m 37.3 mG 0.77 kV/m 40.8 mG 1.69 kV/m 91.4 mG 1.8 kV/m 105 mG Summary of Exposure Scenarios Evaluation for all Scenarios 4.95 kV/m 521 mG

21. 21 Compliance with International Standards At the right of way “ Scenario 5” the external electric field is significantly lower than general public exposure limits

22. 22 Compliance with International Standards At the right of way “ Scenario 5” the external magnetic field is significantly lower than general public exposure limits

23.  Methodology:FDTD method  Software:Empire  Provider:IMST Germany 23

24. 24 * AFRL: Air Force Research Laboratory (AFRL)Air Force Research Laboratory (AFRL)

25.  For standing position  42 different tissue types are represented  The raw file obtained from Air Force Research Laboratory (AFRL).  Model available in 3 mm and 6 mm voxel size  For sitting position  A less detailed model with only 8 tissues and air is utilized in EMPIRE software  Model available in 5 mm voxel size 25

26. Scenario Number Magnetic Flux Density B (mG) Electric Field E (kV/m) 1521.474.949 2621.516.065 3621.516.065 4663.586.485 521.380.165 637.290.745 740.780.766 840.780.766 9521.474.949 1091.411.689 11104.81.806 26 External exposure values of magnetic flux density and electric field for all the eleven exposure scenarios.

27.  Scenario #4 simulation has been conducted for 6 mm voxel model 27

28. 28

29. 29

30. 30 EmaxJmax

31. 31 Anatomical structure of brain location of maximum induced current density in brain

32. 32 location of maximum induced current density in heart Anatomical structure of heart

33. 33 Simulation of Scenarios 7, Scenario 8, Scenario 9, and Scenario 11 were conducted using the sitting body model “less detailed model than the sitting position.

34. 34

35. 35 The maximum induced electric field for all scenarios.

36. 36

37. 37 Induced Maximum Electric Field in the Hands, Writs, Feet and Ankles 0 500 1000 1500 2000 12456791011 Scenario Number Electrioc Field (mV/m) IEEE Worker Limit=2100mV/m

38. 38

39.  A thorough literature survey for exposure to extremely low frequency electro-magnetic field has been conducted and occupational exposure limits have been extracted from relevant standards and guidelines  An Actual 132 KV SEC transmission line data and work exposure scenarios which represent real working condition has been collected from SEC. 39

40.  The external and internal fields as well as induced current densities has been calculated.  The worst case condition in external electric field is less than 75% from ICNIRP occupational limits and less than 30% from IEEE occupational limits.  The worst case condition in external magnetic field is less than 15 % from ICNIRP limits and less than 5% from IEEE occupational limits.  The worst case studied scenario has induced maximum current density for whole body exposure less than 68% from the maximum allowable limit. 40

41.  There is no need for any mitigation actions for the selected working conditions examined in this study. 41

42.  Launching of public awareness campaign to educate general public and reveal the true size and risk of the exposure to EMF problem  Development and/or adoption of exposure limits for external and internal fields. As a starting point, the IEEE standard and limits along with other international standards, should be taking into consideration during preparation of Saudi Standards  Assessment of exposure of EMF for HV 380 KV transmission lines and substations through measurements and simulation. 42

43.  The development of standardized measurement and survey techniques and retain survey reports than include details of the exposure conditions.  Continuous monitoring of the scientific progress of the proposed long term mechanism of interaction between power line EMF and human and adopt their limits when they become established mechanisms. 43

44. 44 Q&A

45. ModelNRPBUniversit y of Utah University of Victoria AFRL Height and Mass 1.76 m 1.77 m1.87 m Original Voxel 2.077x2.077x2.0 21 2x2x3 mm 3.6x3.6x3.6 m 3x3x3 mm Resolution in calculation 2 mm6 mm3.6 & 7.2 mm3 mm & 6 mm Frequency in computation 50 Hz60 Hz 45 AFRL: Air Force Research Laboratory (AFRL) NRPB: National Radiological Protection Board

46. TissueNRPBUniversity of Utah University of Victoria AFRL Brain0.080.170.10.08 Heart0.080.50.10.086 Kidney0.090.270.10.093 Liver0.070.120.070.0374 CSF2.01.51.62.0 46 Comparison Between Conductivity Values for Selected Organs [s/m] CSF:CEREBRAL SPINAL FLUID

47. TissueUTAH Javg (mA/m2) EMPIRE (mA/m2) Relative Difference (%) Brain1.91.6912% Heart2.21.631% Kidney2.82.128 % Liver1.41.344 % CSF4.84.624 % 47 Ez = 10 kV/m By = 33 uT Javg: Organ Average Current Density

48.  Comparisons show that there is difference in results reported because of  Difference in accuracy of the utilized numerical methods  Voxel size, human body model, and organs size and shape  Difference in conductivity values assigned to different organs inside the human body 48