Artificial UV Radiation

Full Profile

General Information

On the electromagnetic spectrum, ultraviolet radiation (UVR) is found between visible light and x-rays, and is divided into three components: UVA (315-400 nm), UVB (280-315 nm) and UVC (100-280 nm).^[1,2] Based on genotoxicity studies, UVC is the strongest genotoxin of the three components; UVA is the weakest.^[2]

Artificial sources of UVR emit a range of wavelengths specific to each source.^[3] Artificial UVR may be used in occupational settings (medicine, industry, business and research) as well as for cosmetic and domestic purposes (sunlamps and sunbeds).^[3] Welding arcs and UV lasers are another source of artificial UVR.^[4]

UV-emitting tanning devices were raised to Group 1, carcinogenic to humans, in a recent IARC review of human carcinogens, with links to skin and ocular melanoma.^[17] IARC plans to undertake a high-priority review of UVR exposure risk among welders at a later date.^[17] Fluorescent lights also emit UVR.^[2] However, studies examining the relationship between melanoma of the skin and exposure to fluorescent lights at work have produced conflicting results and fluorescent lights were classified by IARC as Group 3, not classifiable as to its carcinogenicity to humans.^[1,5]

A 2005 report by an IARC working group recommended policy to restrict or discourage sunbed use by young people, after finding that the risk for developing melanoma was prominently and consistently increased in people who first used indoor tanning facilities in their twenties or teen years.^[3] IARC has scheduled a review of solar radiation, which will also include artificial sources of UVR (use of sunlamps and sunbeds) and components of UVR (UVA, UVB, and UVC).^[5]

Exposure to artificial UVR is most significant via the dermal route.^[1] Exposure to UVR may result in short term skin damage such as burning, fragility and scarring; long term exposures may result in collagen breakdown and decreased skin elasticity.^[6] Data suggest that the use of indoor tanning facilities may produce detrimental effects on the skin's immune response and potentially on the eyes (ocular melanoma).^[3]

The use of certain prescription drugs or exposure to industrial chemicals such as coal tar distillates may cause hypersensitivity to UVR,^[4] and fair skinned individuals are at greater risk of adverse outcomes following UVR exposure.^[7]

Artificial UV radiation has been ranked by CAREX Canada as Group A (immediate high priority) for occupational settings and as Group D (lowest priority) for environmental settings. Prioritization was based on the carcinogenicity and other toxic properties of the substance, the prevalence of exposure in Canada, and the feasibility of assessing exposure.

Regulations and Guidelines

Occupational Exposure Limits (OEL)

The American Conference of Governmental Industrial Hygienists (ACGIH) recognizes ultraviolet radiation as an occupational hazard and recommends different exposure threshold limit values (TLVs) for different UV with wavelengths in air between 180 and 400 nanometres. The recommend TLVs published in 2011 are shown in a figure below. Many Canadian provincial jurisdictions, such as British Columbia, Saskatchewan, Manitoba, New Brunswick, Nova Scotia, and Newfoundland and Labrador adopt ACGIH TLVs as occupational exposure limits.

Canadian Regulations and Guidelines

Regulation/guideline	Year
Radiation Emitting Devices Act	1985[8]
Regulation Amendment: Radiation Emitting Devices Regulations (Tanning Equipment)	2005[9]
Guidelines for Tanning Salon Owners, Operators and Users	2005[10]
Food and Drugs Act: Medical Devices Regulations	1998[11]
Radiological Health Protection Act (NB)	1992[12]
Radiation Health and Safety Regulations (SK)	2005[13]
Guidelines for Tanning Salon Operators (BC)	1997, 2004[14]

Major Sources of Artificial UVR

Electric welding arcs can produce significant levels of UVR within a radius of several metres; gas welding and cutting torches do not produce high levels of UVR.^[15]

Artificial UVR is used in medical and dental practices for procedures such as the treatment of skin diseases and neonatal jaundice, cavity detection and treatment, and for chronic conditions such as seasonal affective disorder (SAD) and sleep disorders.^[3]

Curing lamps emit intense artificial UVR to harden resins and dry paints; these processes are usually enclosed but openings in the enclosure may lead to overexposure.^[15] Germicidal lamps, commonly used for sterilizing materials in hospitals, are strong emitters of UVB and UVC radiation.^[15] Halogen, xenon and metal halide lamps can emit artificial UVR; black lights, incandescent and fluorescent lamps do not generally present a high exposure risk.^[15]

Ultraviolet lasers, which emit a single invisible wavelength of UVR, are used industrially and medically.^[15]

Occupational Exposures

Occupations with potential for exposure to artificial UVR include welders and tanning appliance operators, as well as workers in industrial photo-processes, sterilization and disinfection (sewage effluents, drinking water, swimming pools, operating rooms and research laboratories), non-destructive testing, printing, phototherapy, UV photography, UV lasers, food industry quality control, and discotheques.^[3,4]

Artificial UVR exposure may be mitigated through engineering controls (such as enclosures), however in some applications workers can be exposed by reflection or scattering from adjacent surfaces, a phenomenon which is of particular concern for tanning appliance operators.^[3]

Environmental Exposures

Cosmetic tanning appliances, which may be referred to as sunbeds, sunlamps, or tanning beds, are the main source of artificial UVR exposure for the general public.^[1,3] It has been estimated that powerful tanning units may emit UVR with an intensity 10-15 times greater than that of the midday sun.^[3]

Current tanning appliances emit primarily UVA radiation,^[1] although recently tanning lamps have been manufactured to produce higher levels of UVB in order to mimic the solar spectrum and speed the tanning process.^[6] Indoor tanning facilities are most commonly used by younger women (< 35 yrs) in North America and Northern Europe.^[3]

The Canadian Cancer Society has endorsed the World Health Organization's recommendation that no person under 18 should use artificial tanning equipment.^[16]

Sources

1. IARC monograph summary, Volume 55 (1992) (PDF)
2. NTP 12th Report on Carcinogens for Ultraviolet Radiation Related Exposures (2011)
3. WHO and IARC (2005) Exposure to Artificial UV Radiation and Skin Cancer, Working Group Report (PDF)
4. Ontario Ministry of Labour Ultraviolet Radiation in the Workplace revised March 2009
5. IARC: Complete List of Agents evaluated and their classification (2006) (PDF)
6. WHO Media Centre Factsheet No 287 - Sunbeds, tanning and UV Exposure (2005)
7. Health Canada, It's Your Health: Tanning Lamps (2003) (PDF)
8. Department of Justice Canada, Radiation Emitting Devices Act ( R.S., 1985, c. R-1 )
9. Regulations Amending the Radiation Emitting Devices Regulations (Tanning Equipment), Canada Gazette Vol. 139, No. 4 — February 23, 2005
10. Health Canada, Guidelines for Tanning Salon Owners, Operators and Users (2005) (PDF)
11. Department of Canada Justice: Food and Drugs Act, Medical Devices Regulations (1998)
12. Government of New Brunswick, Radiological Health Protection Act (O.C. 92-84) (1992)
13. Government of Saskatchewan - The Radiation Health and Safety Regulations (2005) (PDF)
14. BC Ministry of Health Services, Guidelines for Tanning Salon Operators (1997; revised 2004) (PDF)
15. Government of Saskatchewan Occupational Health and Safety Division, Solar and Artificial Ultraviolet Radiation: Health Effects and Protective Measures (1999)
16. Canadian Cancer Society, Youth and Artificial Tanning (2008)
17. IARC Monograph Volume 100: A review of human carcinogens—Part D: radiation (2009)
18. Wikimedia Commons Photo: Welding

Other Resources

1. Health Canada: Health Effects of UV Radiation (2008)
2. Health Canada: Skin Cancer (2009)
3. Health Canada: Tanning under lights (2007) (PDF)
4. Health Canada Its Your Health: Preventing Skin Cancer (2006) (PDF)
5. Canadian Cancer Society: Indoor tanning and skin cancer (2009)
6. EU SCCP Opinion on Biological effects of ultraviolet radiation relevant to health with particular reference to sunbeds for cosmetic purposes (2006) (PDF)
7. Health Canada: Frequently Asked Questions on the Radiation Emitting Devices Regulations (Tanning Equipment) (2007)
8. Health Canada, It's Your Health: Tanning Lamps (2003) (PDF)