Ultraviolet radiation (UVR) emitted by the Sun’s energy is a known carcinogen and one we cannot avoid without personal protection. It is the direct cause of 90% of the world’s most common cancer and is responsible for 80% of the visible signs of ageing. Understanding UV radiation is vital in driving behavioural change and taking charge of our skin health.
Ultraviolet (UV) radiation is a type of electromagnetic energy emitted by the sun and artificially by sunbeds. While some sun exposure is essential for processes like vitamin D production, over-exposure can be harmful to human health.
Ultraviolet radiation; cannot be seen or felt; is not related to temperature; can pass through cloud cover and is classified as a ‘Group 1 human carcinogen’ with well-established and proven links to skin cancer, causing at lest 90% of cases worldwide.
UV radiation is classified into three types: UVA, UVB, and UVC. While UVC is absorbed by the Earth’s atmosphere, UVA and UVB reach our skin and can cause significant damage.
UVA radiation is responsible for tanning of the skin. It penetrates the skin at deeper levels than UVB, reaching the middle layer of the skin called the dermis. UVA is commonly referred to as ‘Ageing’ rays because in addition to tanning and causing sun damage which contributes to the development of skin cancer – they are also responsible for around 80% of the visible signs of ageing.
UVA accounts for up to 95 per cent of the UV radiation that reaches the earth’s surface. They are present at fairly consistent levels throughout daylight hours, all-year-round and are able to pass through cloud cover, fog and glass. This means, during our lifetime, we are all exposed to high levels of UVA radiation – highlighting a strong case for all-year-round sun protection.
The image shows a 69 year old man who drove a delivery truck for 28 years. It demonstrates the visual signs of sun damage to the left side of his face caused by UVA that passed through his side vehicle window. What it can’t show is the damage caused to the skin’s cells beneath the surface.
Unprotected exposure to both UVA and UVB radiation causes damage to the DNA in our skin cells, which is the leading cause of skin cancer.
Therefore, tanning of the skin caused by UVA, and reddening or burning of the skin caused by UVB should be considered visual warning signs. The fact is, when our skin changes colour it’s our body’s way of alerting us – letting us know that it is working hard to defend itself from UV radiation and that damage is occurring beneath the skin’s surface.
Damage from both UVA and UVB is cumulative (meaning it builds up over time) and irreparable – once the damage is done, there’s no going back. Skin cancer can develop when unrepaired damage to the skin cells triggers mutations that cause the cells to reproduce abnormally, grow out of control and form tumours. The development of skin cancer varies widely and can take months or years from the point at which sun damage occurs.
While levels of UVA remain more-or-less consistent throughout daylight hours each day, UVB can fluctuate dramatically. The strength of sunburn-producing UV radiation, at the earth’s surface is therefore measured consistently and should be checked daily using the UV index. When the UV index reaches 3, steps should be taken to protect the skin from the damaging affects of UV radiation. To learn more and access the UV Index follow the link below.
