Most people by now are aware that the sun has damaging effects on the skin. Whether it is coming back from the beach with a sunburn or seeing spots on the skin appear for the first time, the sun has a multitude of effect on our health, wellbeing and appearance. The damaging impact of the sun on our skin comes from ultraviolet radiation, which in the main cause of diseases such as skin cancer and melanoma.

What is ultraviolet radiation?

Radiation is the emission of energy and comes in many forms, from high frequency x-rays to low frequency radio waves. In the case of ultraviolet radiation the main source in most people’s lives is the sun, however, it can also come from tanning beds and industrial equipment such as welding torches.
What makes ultraviolet radiation particularly dangerous to the human body is that it is a type of ionizing radiation. This means that ultraviolet rays are capable of removing an electron from an atom, which has the possibility of damaging DNA in cells and causing cancer in the skin. The good news is that UV radiation can’t penetrate deep into the body, so won’t affect deeper organs like the heart or lungs, however, it can still have a devastating effect on the skin.
Skin cancer is one of the leading causing of death in Australia with more than 2,000 Australian’s dying every year from the disease. Two in three Australians will be diagnosed with skin cancer by age 70 and there are approximately 900,000 cases treated every year.
Ultraviolet radiation from the sun comes in two main forms UVA and UVB radiation, which have significantly different effects on the skin.

What is the difference between UVA and UVB radiation?

UV radiation is split up into UVA and UVB types of radiation by measuring their wavelength. The shorter the wavelength of UV radiation the more damaging it is to the skin, however the less able it is to penetrate the atmosphere and layers of the skin.

UVA radiation has a longer wavelength than UVB radiation and thus more of it reaches the surface of the earth. In fact 95% of the UV radiation from the sun that reaches the earth is UVA radiation. Because UVA radiation has a longer wavelength it can penetrate deeper into the skin, causing immediate tanning and well as skin aging and wrinkling. While previously thought to have no impact on skin cancer there is now evidence that it can have an indirect effect on damage to DNA in cells and can contribute to the development of the disease.

UVB radiation has a shorter wavelength than UVA radiation and so it is much less present on the surface of the earth. However, it has more energy than UVA radiation and thus has a more severe impact on the skin even though it can’t penetrate as deeply as UVA radiation. It is the main cause of sunburns, skin cancer and melanoma.