Non ionising radiation

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Non ionising radiation

  1. 1. Hazards and principles of control
  2. 2. Non-ionising radiation  Photons with energy less than 12.4 eV  Wavelength > 100nm
  3. 3. Non - Ionizing Ionizing
  4. 4. Region Wavelength Frequency Ultraviolet 100 – 400 nm Visible 400 – 770 nm Infrared 770 nm – 1 mm Radio frequency 3 kHz - 300 GHz Extremely low 3 Hz - 3 kHz frequency
  5. 5. The harmful effects caused by non-ionising radiation are mainly due to the absorption of energy which results in tissue heating
  6. 6. The longer the wavelength, the deeper the radiation will penetrate into the body
  7. 7. Higher energy NIR (in the UV region) can also cause photochemical interactions
  8. 8. Biological effects  Effects on the eye  Skin burns  Damage to internal organs  Cancer (UV)
  9. 9. The type of eye damage depends on the wavelength
  10. 10. The type of eye damage depends on the wavelength
  11. 11. 100 to 400 nm
  12. 12. UV Regions Wavelength (nm) UVA “Black light” 315–400 UVB Erythema 280-315 UVC Germicidal 100-280
  13. 13. UV – Effects on the skin Skin ageing UV-A Erythema (“Sunburn”) UV-B Cancer UV-B Photosensitisation
  14. 14. UV-C UV-B UV-A Picture source: Canadian Centre for Occupational Health and Safety www.ccohs.ca/oshanswers/phys_agents/ultravioletradiation.html
  15. 15. Erythema Reddening is due to blood flowing to the affected area in response to skin damage
  16. 16. Erythema Delayed response  Starts 2 to 4 hours after exposure  Peaks after 14 to 20 hours  Can last 48 hours
  17. 17. Skin Cancer
  18. 18. Basal cell carcinoma Rarely metastasize and rarely cause death Easily treated with surgery or radiation
  19. 19. Squamous cell carcinoma Can metastasize if untreated
  20. 20. Malignant melanoma Most serious type of skin cancer Less common than other types
  21. 21. Sunbeds emit mostly UVA, but between 0.5 and 4% of their total output can be UVB Source: www.sunsmart.org.uk/
  22. 22. Sunbeds are estimated to cause around 100 deaths from melanoma every year in the UK Source: www.sunsmart.org.uk/
  23. 23. Keratitis Cataracts
  24. 24. UV – Effects on the eye Photokeratitis “welder’s flash” Caused by exposure to UV-B or UV-C
  25. 25. UV – Effects on the eye  Cataracts – caused by UV-A
  26. 26. 100 to 400 nm
  27. 27. Infrared regions Wavelength IR-A 770–1400 nm IR-B 1.4–3.0 mm IR-C 3.0 mm–1 mm
  28. 28. Infrared radiation  Skin burns  Effects on eyes
  29. 29. “Glassworker’s cataract” Picture source: National Eye Institute, U.S. National Institutes of Health
  30. 30. IR – Eye absorption
  31. 31. IR – Skin absorption
  32. 32. Radiofrequency radiation Extremely Low Frequency (ELF) <3KHz Low Frequency (LF) 300KHz-30KHz Medium Frequency (MF) 3MHz-300KHz High Frequency (HF) 30MHz-3MHz Very High Frequency (VHF) 300MHz-30MHz Microwave 300GHz-300MHz
  33. 33. Microwaves and Radio Waves  Tissue heating  Burns  Organ damage  Reproductive effects
  34. 34. Microwaves and Radio Waves The most dangerous frequencies have wavelengths similar to body dimensions
  35. 35. <30 MHz 30-300 MHz >300 MHz Low absorption High absorption Surface heating Uniform distribution
  36. 36. Microwaves and Radio Waves Indirect effects  Electric shock  Pacemakers
  37. 37. Extremely Low Frequency (ELF) Electromagnetic Fields  Frequency < 3 kHz  Wavelength considerably larger than human body
  38. 38. Extremely Low Frequency (ELF) Electromagnetic Fields  Some concerns regarding  Cancer  Reproductive effects  Neurological effects  Other effects  Jury still out
  39. 39. Prevention Turn off the source before starting work on equipment
  40. 40. Containment
  41. 41. Shielding
  42. 42. Distance
  43. 43. Distance Inverse square law applies
  44. 44. Distance Relative exposure 1 metre 1 2 metres 0.25 4 metres 0.06
  45. 45. Restrict access No entry
  46. 46. Reduce exposure time
  47. 47. PPE
  48. 48. Occupational Health Management Supervision Maintenance Procedures Prevention Auditing Engineering Testing Health surveillance Work Practices Monitoring PPE Information Training Housekeeping
  49. 49. Further information  www.hse.gov.uk/radiation/nonionising/  www.sunsmart.org.uk/  www.radhazonline.com/Appnotes.asp  www.cdc.gov/niosh/emf2.html  www.cdc.gov/niosh/topics/emf/  www.ccohs.ca/oshanswers/phys_agents/ultravi oletradiation.html  www.hpa.org.uk/Topics/Radiation/RadiationAZ/
  50. 50. Picture credits  Kavitha @Stock.xchng (www.sxc.hu)  Zulema011 @Stock.xchng (www.sxc.hu)  Mailsparky @Stock.xchng (www.sxc.hu)  Chillipadi @Stock.xchng (www.sxc.hu)  Canadian Centre for Occupational Health and Safety (www.ccohs.ca)  National Eye Institute, U.S. National Institutes of Health (http://www.nei.nih.gov/)  Occupational hygiene training association (www.ohlearning.com)  www.sunsmart.org.uk  WHO (www.who.int)  Wikipedia commons
  51. 51. http://www.slideshare.net/mikeslater occhygiene@btconnect.com http://diamondenv.wordpress.com Twitter @diamondenv Mike Slater
  52. 52. Mike Slater, Diamond Environmental Ltd. (occhygiene@btconnect.com) This presentation is distributed under the Creative Commons Attribution-NonCommercial-ShareAlike UK:International Licence

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