The Importance of Sun Safety

Australia has the highest rate of skin cancer globally. According to the National Health and Medical Research Council, over 400,000 Australians were treated for non-melanoma skin cancers in 2008 and approximately 11,000 Australians were diagnosed with melanoma in 2011. It is expected that 1 in 3 Australians will be treated for a skin cancer in their lifetime.

The International Agency for Research on Cancer has classed Ultraviolet (UV) radiation as a class one carcinogen. This class is reserved for substances known to cause cancer in humans. There are 3 main types of UV radiation:

  • minimal UVC penetrates the ozone layer
  • UVA and UVB not only penetrates the ozone layer but are also are related to skin cancer.

The World Health Organisation developed a classification system called the UV Index that is designed to quantify how much UV radiation is at the earth’s surface and what measures to take to avoid excessive exposure. The Bureau of Meteorology in Australia releases this information daily. Solar or sun damage can occur anytime when the UV Index is above 3. It is important to remember that the UV Index is not related to how much heat is felt on the skin.

UV exposure is affected by several factors including:

  • lower latitude which increases UV exposure as the sun’s rays has less distance to travel
  • higher altitude which increases UV exposure by about 10% every 1000 metres
  • reflective surfaces such as water, snow and even scattered clouds.

Scattered clouds can intersperse UV radiation so on cloudy days the UV Index can still be relatively high.

The Slip Slop Slap campaign released in 1980 was the most significant campaign to change behaviours regarding sun protection. Reducing UV radiation exposure is a major behavioural change that can reduce skin cancer from developing. You can decrease exposure by:

  • applying sunscreen regularly
  • wearing protective clothing including sunglasses for eye protection
  • physical protection such as shade and umbrellas.

Sunscreens have been developed with approximately 98% UVB protection (SPF50+). Most clothing is thought to be about SPF75 protection although this can be less for more sheer fabrics. Sunglasses are an important sun-safe accessory but you must read the rating systems on the label. The price of sunglasses or the darkness of the lens does not always correlate to better UV protection.

Correct use of sunscreen is important to ensure adequate protection so remember to reapply sunscreens every 2 hours or more frequently if swimming, exercising or excessive sweating. Inadequate application of sunscreen can lessen protection by 50% of what is expected when applied correctly. It is also important to remember to check the use by date and ensure that your sunscreen is kept in a cool, dry place. Sunscreens are less effective when kept in continuous hot temperatures such as the glovebox of your car.

Article by Dr Linda Haines, General Practitioner for Aspen Corporate Health. Published 17/11/15