UV Rays and Sun Protection – Part 1

Sun protection. I’m sure you’ve heard all of us at With Grace pushing the importance of it for our skin, but what exactly does sunscreen and employing sun protective behaviours do for our skin? These interventions protect us from harmful ultraviolet (UV) radiation, but what is UV radiation and how is that affecting our skin on a daily basis? In this 2-part series I’ll break down the different types of UV rays and their effects on the skin, and then what we can do to help protect our skin from its effects.

So first up, what is UV radiation? It’s a form of energy that comes from the sun and moves in invisible waves. These little waves are very powerful and have the ability to interact with our skin and cause changes. There are 3 types of UV radiation: UVA, UVB, and UVC. UVC is completely blocked out by the Earth’s atmosphere. UVB is partially blocked by the ozone layer and makes up 5% of the total UV radiation that makes its way to the Earth’s crust. UVA is the least energetic of the 3 types but makes up 95% of the total UV radiation within our atmosphere. UV radiation can occur in any type of weather, so just because it’s sunnier doesn’t mean that the UV radiation will be higher and vice versa. 

UVB rays can only penetrate to the base of the epidermis (the most superficial portion of our skin) and is more prevalent in the summer months. This is the type of UV radiation that causes sunburn and pigmentation. The onset of these tends to be delayed, occurring within 6-24 hours after sun exposure. The pigmentation process caused by UVB rays is a stress response in our skin and is a sign that our body is trying to protect our DNA from damage. The pigment granules form a cap over our DNA to protect it. While this does offer some further protection from UV radiation, it does not rule out the need for sunscreen and other sun protection.

UVB rays can cause DNA damage in two ways: 1. By being directly absorbed by our DNA which can alter its makeup; and 2. By creating reactive oxygen species (AKA free radicals) which can cause inflammation and damage to DNA. Accumulated DNA damage can lead to tumours and cancers.

UVA rays can penetrate deeper into the dermis portion of our skin and is not affected by the change in seasons. UVA rays can play a part in premature ageing due to their ability to damage proteins and lipids within the dermis, so this can attribute to conditions like skin laxity and wrinkling. UVA rays can also create reactive oxygen species within our skin, and this can cause inflammation and DNA damage. As with UVB rays, accumulated DNA damage from UVA rays can also lead to tumours and cancers.

A way that we can monitor UV ray intensity is by looking at the UV index. This tool is designed to give a rating of the UV ray intensity and helps to advise us on the strength of sun protection needed to protect our skin. The rating starts at 0 and has no upper limit. It is recommended that you wear sun protection when the UV rating is 3 or higher. When the UV rating is greater than 8 it is recommended that you have a strong amount of sun protection on and it may also be best to try and avoid sun exposure all together. 

A great way to monitor the UV index is through the SunSmart app. It will let you know the expected peak UV rating, recommended times to be wearing sun protection, and can also advise how much sunscreen you should be wearing dependant on the clothing that you are wearing for the day. You can also find the UV index on the weather page in Australian daily newspapers or on the Bureau of Meteorology or the SunSmart website.

Now we know what negative effects UV rays can have on our skin, what can we do to protect it? Stay tuned for part 2...