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FAQs about UV radiation

How dangerous is UV radiation?
Why does Australia have high levels of UV radiation?
Can I feel UV radiation?
How does UV radiation from the sun reach me on the ground?
Why do I still get sunburnt in the shade?
Why do I still get sunburnt on a cloudy day?
Is temperature related to levels of UV radiation?
What is windburn?
Is UV radiation from a solarium the same as UV radiation from the sun?
Don't I need to get more sun to help me avoid vitamin D deficiency?

How dangerous is UV radiation?

UV radiation can damage cells of living organisms. Skin cancer can grow when our skin cells are damaged. By contrast, infrared radiation, visible light and even radiation from microwaves or the TV are not strong enough to damage cells of the body.

Why does Australia have high levels of UV radiation?

Australia experiences some of the highest levels of UV radiation in the world because we are close to the equator where the sun sits and have a lot of clear blue-sky days. The Earth's orbit also takes countries in the southern hemisphere (Australia included) closer to the sun in their summertime than countries in the northern hemisphere are during their summer.

Can I feel UV radiation?

The sun sends out visible light, infrared and UV radiation. Our eyes see the visible light as sunlight. Our skin feels the warmth of infrared radiation. Our skin cannot however detect UV radiation – we cannot see or feel it so it can damage our skin without us knowing. When people say they ‘feel themselves getting burnt' or they ‘feel a sting in the sun', they are confusing infrared radiation with UV radiation.

How does UV radiation from the sun reach me on the ground?

UV radiation can reach you in a direct path from the sun. The closer you are to the sun, the less distance UV has to travel and the stronger it will be. UV radiation can also be scattered by particles in the air and reflected from nearby buildings and ground surfaces. These are sometimes called indirect sources of UV radiation.

Why do I still get sunburnt in the shade?

Total UV radiation present at a given location = direct UV + indirect UV.

Shade forms a barrier between you and the sun, which protects you from direct UV radiation. You may still get enough exposure to cause sunburn from indirect UV radiation, however. A general rule of thumb is that if you can see a lot of sky then UV radiation can reach you.

Why do I still get sunburnt on a cloudy day?

It is possible for UV radiation to pass through clouds. The amount of UV radiation that gets through depends on how thick the clouds are. Heavy cloud reduces UV levels. UV levels on lightly overcast days can be similar to that of a cloud-free day. UV levels rise and fall as clouds pass in front of the sun on a day of scattered cloud. On a cloudy day, try checking the real time UV graph to see the effects.

Is temperature related to levels of UV radiation?

Temperature relates to the amount of infrared radiation present in sunlight, not UV radiation. Temperature should not be used as a guide to when sun protection is needed. When the temperature is cool, it means there is less infrared radiation, but UV levels can still be high.

What is windburn?

There is no such thing as windburn. The wind may dry your skin but cannot burn it.

Is UV radiation from a solarium the same as UV from the sun?

Yes. Solariums use UV radiation to give people a tan. Levels of UV radiation can be up to three times as strong as the midday sun.

Don't I need to get more sun to help me avoid vitamin D deficiency?

Vitamin D helps to develop and maintain healthy bones and UV radiation from the sun is one of the best sources for vitamin D.

From September to April, UV levels are three and above in Victoria, which is enough to cause skin damage and skin cancer so sun protection is needed. During these months most people receive enough vitamin D simply by going about their day-to-day activities. Generally you only need a few minutes of sun exposure to the face, arms and hands, or equivalent area of the skin, before 10 am or after 3 pm, on most days of the week. Adults and children with naturally very dark skin may need three to six times these exposure times.

From May to August UV levels are generally low (below 3) in Victoria so sun protection is not needed unless you are in alpine areas or near highly reflective surfaces such as snow or water.

To get enough sun over the winter months, expose faces, arms and hands (or equivalent area of skin) to the sun for two to three hours over the week. Adults and children with naturally very dark skin may need three to six times these exposure levels.