Hazards and principles of control
Non-ionising radiation
 Photons with energy less than 12.4 eV
 Wavelength > 100nm
Non - Ionizing   Ionizing
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
The harmful effects caused by
non-ionising radiation are mainly
due to the absorption of energy
which results in tissue heating
The longer the wavelength, the
deeper the radiation will
penetrate into the body
Higher energy NIR (in the UV region)
can also cause photochemical
interactions
Biological effects
 Effects on the eye
 Skin burns
 Damage to internal organs
 Cancer (UV)
The type of eye damage depends on the wavelength
The type of eye damage depends on the wavelength
100 to 400 nm
UV Regions

                         Wavelength (nm)
   UVA   “Black light”      315–400

   UVB   Erythema           280-315

   UVC   Germicidal         100-280
UV – Effects on the skin

    Skin ageing            UV-A
    Erythema (“Sunburn”)   UV-B
    Cancer                 UV-B
    Photosensitisation
UV-C                   UV-B        UV-A


Picture source: Canadian Centre for Occupational Health and Safety
www.ccohs.ca/oshanswers/phys_agents/ultravioletradiation.html
Erythema
Reddening is due to
blood flowing to the
affected area in
response to skin
damage
Erythema
Delayed response
 Starts 2 to 4 hours
  after exposure
 Peaks after 14 to 20
  hours
 Can last 48 hours
Skin Cancer
Basal cell carcinoma
Rarely metastasize and rarely cause death
Easily treated with surgery or radiation
Squamous cell carcinoma
Can metastasize if untreated
Malignant melanoma
Most serious type of skin cancer
Less common than other types
Sunbeds emit
mostly UVA, but
between 0.5 and
4% of their total
output can be UVB




Source: www.sunsmart.org.uk/
Sunbeds are
estimated to
cause around
100 deaths from
melanoma every
year in the UK




Source: www.sunsmart.org.uk/
Keratitis




Cataracts
UV – Effects on the eye
Photokeratitis
“welder’s flash”

Caused by
exposure to
UV-B or UV-C
UV – Effects on the eye
 Cataracts – caused by UV-A
100 to 400 nm
Infrared regions

            Wavelength
     IR-A   770–1400 nm
     IR-B   1.4–3.0 mm
     IR-C   3.0 mm–1 mm
Infrared radiation
 Skin burns
 Effects on eyes
“Glassworker’s cataract”




  Picture source: National Eye Institute, U.S. National Institutes of Health
IR – Eye absorption
IR – Skin absorption
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
Microwaves and
Radio Waves
 Tissue heating
 Burns
 Organ damage
 Reproductive effects
Microwaves and
Radio Waves
The most
dangerous
frequencies have
wavelengths
similar to body
dimensions
<30 MHz             30-300 MHz         >300 MHz




 Low absorption        High absorption   Surface heating
Uniform distribution
Microwaves and
Radio Waves
Indirect effects
   Electric shock
   Pacemakers
Extremely Low Frequency (ELF) Electromagnetic Fields

                           Frequency < 3 kHz
                           Wavelength considerably
                            larger than human body
Extremely Low Frequency (ELF) Electromagnetic Fields
                               Some concerns
                                regarding
                                  Cancer
                                  Reproductive effects
                                  Neurological effects
                                  Other effects

                               Jury still out
Prevention
Turn off the source
before starting
work on
equipment
Containment
Shielding
Distance
Distance




Inverse square law applies
Distance   Relative
           exposure
1 metre    1
2 metres   0.25
4 metres   0.06
Restrict access




         No entry
Reduce exposure time
PPE
Occupational Health Management

                          Supervision
                          Maintenance
                          Procedures
          Prevention
                          Auditing
          Engineering     Testing
                          Health surveillance
         Work Practices
                          Monitoring
              PPE         Information
                          Training
                          Housekeeping
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/
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
http://www.slideshare.net/mikeslater

occhygiene@btconnect.com

http://diamondenv.wordpress.com

Twitter @diamondenv


Mike Slater
Mike Slater, Diamond Environmental Ltd. (occhygiene@btconnect.com)




     This presentation is distributed under the Creative Commons
                Attribution-NonCommercial-ShareAlike
                        UK:International Licence

Non ionising radiation