Episode #119 - UV radiation

VGS Did you know that putting on your sunglasses is one of the ways to protect your eyes from cataract? We are talking about ultraviolet rays today, UV rays. Where do they come from? What impact do they have on your health? How can you protect yourself? And our expert today is Dr. Cornelia Baldermann. Welcome Cornelia.

CB Hi.

VGS Where do UV rays come from?

CB UV or ultraviolet radiation comes from the sun but it can also be artificially generated, for example in sun beds. UV radiation is not perceivable, you can’t see that, you can’t sense it, so, this is very unfortunate because UV radiation is giving us more health effects, negative health effects, for example, in short-term, sunburn, you know, eye inflammation and for the long-term, premature skin ageing and skin cancer. Also cancer of the eyes. UV radiation is classified as carcinogenic to humans. Why? Because UV radiation is damaging DNA and too much UV is damaging [the cells] too much, so they can’t repair this damage again. And therefore these affected cells can degenerate into cancer cells. The only positive effect of UV radiation is the synthesis of vitamin D in our body. But this is happening simultaneously to the negative effects and before you are sunburned. So, be careful about your sun exposure.

VGS So we're going to come back to vitamin D in a minute. Let's first talk about how we can protect ourselves from ultraviolet radiation.

CB UV protection is very necessary, you heard, because of the skin cancer, for example, and especially for the children. But it’s very very easy, so, do it like this: First, avoid UV exposure. Too much UV exposure means, seeking shade, using an umbrella or don’t even go outside in the midday time. Secondly, what you can do is to cover [yourself] up. So use a broad-brimmed hat, use sunglasses for your eyes, as you shared before, use clothes and also shoes so that the body is protected. If there is already unprotected skin, then you can use sunscreen for that.

VGS So what about vitamin D? Aren't we concerned about vitamin D when we take all of these protective measures because we are supposed to go out and exercise and walk in the woods and out in the sun, right?

CB Yeah, this is a good question because vitamin D is very important for our health. But sun protection measures don’t mean to block the vitamin D synthesis. It’s still running, just in a delayed way. So the main point is, don’t go out in the sun just for getting Vitamin D, this is not necessary. There is a pill to treat vitamin D deficiency, but no pill to treat skin cancer.

VGS I have another question for you. I have darker skin, so I have more melatonin, does that mean that I’m more protected from ultraviolet radiation?

CB Dark skinned people, like you, are not so sensitive to UV radiation as fair skinned people. The lighter your skin, the earlier you get the UV exposure negative effects. So, it’s very important that you know your skin, how sun sensitive is your skin and when it will come to sunburn. When you know this, with this knowledge, you can already manage your sun exposure and your time outdoors.

VGS How would we know about UV radiation if we can’t see it or sense it?

CB Yeah, this is really a problem, but we have a solution. There is the UV index. This is a scale, with whole numbers, starting with one to eleven and above, and the higher this number the [more] intense the UV radiation is. So it means when you start to get outside, so use, for example, weather apps or something like that, showing you the UV index or use the SunSmart app, showing you your own sun protection times.

VGS Cornelia, explain to us if we are not in direct sunlight, if we are in shade, are we still exposed to UV radiation?

CB Yes, shade reduces the UV radiation, but it’s not blocking the UV radiation totally. So it means UV radiation is scattered and therefore, everywhere you are. In shade you can get burnt, you can get a tan and also, you can get vitamin D. Thus, shade alone does not mean 100 per cent UV protection. So, go out and be aware of your sun exposure and sun protect yourself. Let me say, this all sounds [like you’re] not allowed to go out in the sun. This is not the case, of course not. To be in the sun and to be outside, it’s very healthy. So, go out, enjoy the sun and do your sun protection very clever and in the end, avoid sunburn.

VGS Thank you Cornelia, there you have it, that was Science in 5 today. Until next time then, stay safe, stay healthy and stick with science.