non ionising radiation
TRANSCRIPT
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 frequency
3 Hz - 3 kHz
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
Picture source: Canadian Centre for Occupational Health and Safety www.ccohs.ca/oshanswers/phys_agents/ultravioletradiation.html
UV-BUV-C UV-A
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 cancerLess 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
Uniform distribution
High absorption Surface heating
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
Prevention
Engineering
Work Practices
PPE
Supervision
Maintenance
Procedures
Auditing
Testing
Health surveillance
Monitoring
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/ultravioletradiation.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
http://diamondenv.wordpress.com
Twitter @diamondenv
Mike Slater
Mike Slater, Diamond Environmental Ltd. ([email protected])
This presentation is distributed under the Creative CommonsAttribution-NonCommercial-ShareAlike
UK:International Licence