2.1 Strategies for protection from excessive exposure to ultraviolet radiation

From Clinical Guidelines Wiki
Clinical practice guidelines for keratinocyte cancer > 2.1 Strategies for protection from excessive exposure to ultraviolet radiation


Background

While not always possible, minimising exposure to ultraviolet (UV) radiation from the sun is the most effective strategy to prevent skin cancer. This includes planning outdoor activities to occur outside of the peak UV period (2 hours either side of solar noon), when an estimated 60% of the day’s UV radiation occurs. Around midday, skin will burn more quickly, and be exposed to more UVA as well as UVB, than earlier or later in the day. Outside of these times, the UV can still be intense, so sun protection is necessary for all times when the UV index is 3 or above. For the best protection during the daily sun protection times, people should use all five SunSmart steps – clothing, sunscreen, a broad-brimmed hat, shade and sunglasses. The Bureau of Meteorology and the SunSmart App provide up-to-date sun protection times for regions across Australia.

Back to top

Overview of evidence (non-systematic literature review)

Keratinocyte cancer occurs more frequently on parts of the body that are habitually exposed to sunlight.[1] Health professionals should advise and encourage everyone to practise the following strategies for protection against excessive exposure to UV radiation.

Hats, clothing and sunglasses

Wear broad-brimmed or legionnaire hats (those which cover face, neck and ears reduce the UV radiation exposure to the face and eyes) and comfortable clothing that protects the arms, legs, body and neck from the sun.

Choose a close-fitting, wrap-around style of sunglasses. Check the swing tag to make sure they meet the Australian Standard for eye protection.[2][3] The Standard has five categories of sun protection – choose category 2 or higher. These lenses absorb more than 95% of UV radiation.

Choose closely woven fabrics that can’t be seen through when held up to the light and that covers as much of the body as practicable. Some clothing is specifically tested for its ability to provide protection from UV radiation. This clothing uses an Ultraviolet Protection Factor (UPF) rating scheme developed by Standards Australia to guide consumers.[4]

Back to top

Shade

Seek shade. Whenever possible, choose activities which can be conducted in or moved to shady areas. It is important to remember that it is possible to get burnt in the shade by reflected UV rays, so use clothing and sunscreen as well.

Sunscreen

Sunscreen reduces the risk of cSCC and numbers of actinic (solar) keratoses, which are known precursors of cSCC.[5][6]

Apply a sunscreen liberally with a sun protection factor (SPF) of 30 or greater to all exposed areas of skin and reapply regularly.[7] A full-body application for the average adult would be 35mls (equivalent to 7 teaspoons) of sunscreen. The Therapeutic Goods Administration (TGA) permits labelling of a sunscreen up to SPF50+.[8]

All sunscreens approved to be sold in Australia offer broad-spectrum protection (protection from both UVA and UVB wavebands within sunlight).

Given that consumers generally do not apply sunscreen thickly enough, sunscreen should not be relied on as the only form of protection. Apply sunscreen 20 minutes before going outside and reapply it at least every 2 hours. For specific circumstances such as swimming, a water-resistant sunscreen should be selected.

Sunscreens should not be used to extend the duration of sun exposure as this will likely to lead to increased risk of excessive UV radiation exposure. It is advisable to apply sunscreen every day to exposed parts of the skin when the UV index is predicted to reach 3 or above.[9]

Some sunscreens may contain nanoparticles to improve cosmetic appeal and the efficacy of the product. Nanoparticles have not been found to cause harm when used as ingredients in sunscreens and when sunscreens are used as directed.[10]

Back to top

Window glass

Each type of glass has different UV transmission properties. For example, typical household window glass is equivalent to a SPF14 sunscreen in filtering UVB rays. Glass windows typically block out most UVB radiation, but the amount of UVA radiation that penetrates through different types of glass can vary greatly.[11]

Back to top

Home solariums

Exposure to artificial sources of UV radiation in a solarium (sun bed or tanning bed) increases the risk of developing cutaneous melanoma, cutaneous squamous cell carcinoma (cSCC), basal cell carcinoma (BCC), ocular melanoma, eye damage and premature aging of the skin. There is no such thing as a ‘safe tan’ and there are no substantiated health benefits, including boosting vitamin D levels, attributable to exposure to artificial UV radiation in a solarium.[12]

Commercial solariums are banned in all Australian states and territories except the Northern Territory, where there are no commercial UV tanning businesses. Private ownership and personal use of solariums remain legal (and unregulated) in all states and territories.

Cancer Council Australia, the Cancer Society of New Zealand and the Australasian College of Dermatologists do not recommend the use of artificial UV tanning devices for cosmetic purposes in any circumstances (see: Cancer Council Australia Position statement on private solariums).


Key point(s)
  • Clinicians should strongly encourage patients to protect themselves from exposure to sunlight when the UV index is 3 or above, and talk to their patients about the use of hats, clothing, shade and the timing of outdoor activities for the purpose of UV protection. Patients should also be encouraged to apply SPF30+ sunscreen (approved by the Therapeutic Goods Administration) regularly and in conjunction with other forms of sun protection.
  • Clinicians should strongly counsel patients against personal home use of sunbeds or sunlamps for cosmetic tanning purposes if these behaviours are suspected or revealed during consultations.

Back to top



References

  1. English DR, Kricker A, Heenan PJ, Randell PL, Winter MG, Armstrong BK. Incidence of non-melanocytic skin cancer in Geraldton, Western Australia. Int J Cancer 1997 Nov 27;73(5):629-33 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/9398037.
  2. Standards Australia. Eye and face protection - Sunglasses and fashion spectacles - Part 1: Requirements (AS/NZS 1067.1:2016). Homebush, NSW: Standards Australia.; 2016.
  3. Standards Australia. Eye and face protection - Sunglasses and fashion spectacles - Part 2: Test methods (AS/NZS 1067.2:2016). Homebush, NSW: Standards Australia; 2016.
  4. Standards Australia. Sun protective clothing - Evaluation and classification (AS/NZS 4399:2017). Homebush, NSW: Standards Australia; 2017.
  5. Green A, Williams G, Neale R, Hart V, Leslie D, Parsons P, et al. Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial. Lancet 1999 Aug 28;354(9180):723-9 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/10475183.
  6. Naylor MF, Boyd A, Smith DW, Cameron GS, Hubbard D, Neldner KH. High sun protection factor sunscreens in the suppression of actinic neoplasia. Arch Dermatol 1995 Feb;131(2):170-5 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/7857113.
  7. Standards Australia. Sunscreen products - evaluation and classification (AS/NZS 2604-2012). Homebush, NSW: Standards Australia; 2012.
  8. Therapeutics Goods Administration. Sunscreen standard 2012: information for retailers. Canberra, ACT: Department of Health, Commonwealth Government of Australia; 2012 Nov 13 [cited 2018 Oct 4] Available from: https://www.tga.gov.au/sunscreen-standard-2012-information-retailers.
  9. Whiteman DC, Neale RE, Aitken J, Gordon L, Green AC, Janda M, et al. When to apply sunscreen: a consensus statement for Australia and New Zealand. Aust N Z J Public Health 2019 Apr;43(2):171-175 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/30681231.
  10. Smijs TG, Pavel S. Titanium dioxide and zinc oxide nanoparticles in sunscreens: focus on their safety and effectiveness. Nanotechnol Sci Appl 2011 Oct 13;4:95-112 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/24198489.
  11. Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Film, glass and materials testing. Canberra, ACT: Department of Health, Commonwealth Government of Australia; [cited 2018 Oct 4] Available from: https://www.arpansa.gov.au/our-services/testing-and-calibration/ultraviolet-radiation-testing/film-glass-materials-testing.
  12. Scientific Committee on Health, Environmental and Emerging Risks (SCHEER). Opinion on biological effects of ultraviolet radiation relevant to health with particular reference to sunbeds for cosmetic purposes. Luxembourg: European Commission; 2016 Nov 17 [cited 2018 Oct 4] Available from: http://ec.europa.eu/health/scientific_committees/scheer/docs/scheer_o_003.pdf.

Back to top