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  1. Sunscreen…




  • Two main risk factors for photo aging
    • Chronic exposure to sun. Chronic exposure to ultraviolet radiation is associated with cancer, immune supression , sunburn and other health risk factors
    • Smoking
  • Types of skin cancers
    • Basal cell
    • Squamous cell
    • Melanoma
  • Ultraradiation increases the likelihood of all these skin cancers occuring
  • Sunscreen reduces the likelihood of all these skin cancers from occuring
  • Types of ultraradiation
    • UVA. Longer wavelengths, cause DNA damage because they penetrate more deeply
    • UVB. Shorter wavelengths, cause classic sunburn.
  • Both UVA and UVB are linked to skin cancers, so you need a sunscreen product which is broad.
  • SPF (Sun protection fact)
    • UV index tells you how long it takes for you to get a burn e.g. 10 minutes. An SF of 15 on that day will extend that out to 150 minutes.
    • Higher SPF = better protection. Small benefit beyond SPF 30 (little difference between 30 and 50).
    • Apply every 2 hours rather than having an SPF of 50.
  • Two kinds of sunscreen components:
    • Physical blockers e.g. zinc oxide and titanium oxide
    • Chemical absorbers of the UV radiation (they convert UV rays to heat to dissipate the energy)
  • Which sunscreen component is best?
    • Both are effective, most important thing to do is find a broad spectrum which has been approved, and has an SPF over 30.
  • Sunscreen myths:
    • Organisations suggest avoid certain sunscreen products which contain oxybenzone and retinyl palmitate which they claim causes harm in humans. They point to studies which studied mice which ingested large amounts of oxybenzone, causing the cancers. Studies in the European Union have found no harm from oxybenzone.
    • There are no evidence that putting oils on your skin protects you from skin cancer.
  • How much sunscreen?
    • 30mL (shot glass) or enough to cover your body, so, 150mL which might be an entire bottle will be used for an entire family, so people who buy expensive sunscreens of $50 might limit their use of sunscreen, causing a pig problem of not enough sunscreen being applied.
    • Most people only use 1/4 of the sunscreen recommended.
  • What about if you have to tan for competitions?
    • There is a reason why governmants have banned tanning beds for those aged less than 18: There is a strong link between tanning beds and skin cancer and photoaging.
  • Practical applications: Apply an SPF product of 30+ which is inexpensive, which has a broad components of physical and chemical blockers, put on 15 minutes before the sun, and apply 30 ml of a shot glass full of sunscreen to cover your entire body, and try and avoid times between 10am-2pm/ , and don’t forget to reapply in 2 hours, regardless if it is an SPF of 50.