Tanning and UV Light
At Electric Beach we believe in smart tanning. That is to say that we believe that by keeping ourselves informed on the science of tanning, we can improve tanning efficiency. Unfortunately, when researching UV effects on human health we first need to peel back the misinformation produced by ‘Big Pharma’. When skin burns it not only affects your tan but the health of the skin. UV light or Ultraviolet radiation has a higher frequency and shorter wavelength than the visible light spectrum. It forces the skin to produce melanin which acts as a ‘shield’ against the sunlight. This shield becomes more effective with the darkening of the melanin.
Simply put, tanning is your skin protecting itself against the sun. Human skin has evolved over hundreds of thousands of years to provide that protection (FYI body hair also provides sun protection but we’ll not go into that). To start talking about the body responses to sunlight, we must firstly talk about UV light in a little more depth. There are three type of UV light that planet earth is exposed to UVA, UVB and UVC. UVC is all but filtered out by the atmosphere surrounding earth so our skin, as far as the tanner is concerned is unaffected. UVA and UVB light are discussed below. This is where it gets technical. The longer the wavelength, the greater its penetrating ability. Whether that is a ‘filter’ (atmosphere, cloud, suncream or windows) or the skin.
You might think it unusual that UVB is being mentioned before UVA but in any tanning programme it is important to have higher concentrations of UVB first especially in the fairer skinned individuals. This is because UVB is responsible for the production of melanin in the skin. This production can carry on a couple of days after exposure. It is also responsible for production of vitamin D. UVB rays has a wavelength of 290-320 nanometers. The amount of UVB that reaches the earth surfaces depends on the declination of the Sun (how high the sun is in the sky relative to the observer). This means that the time of year as well as the time of day will affect the amount of UVB that reaches the surface as light has to travel through a thicker proportion of the atmosphere when the sun is at a lower declination and when it is higher in the sky more UVB will get through. We experience the most UVB from the sun when it is at its zenith (highest point in the sky). Above 23.5 degrees latitude (the angle of the earth’s axis) the sun will not ever be directly overhead irrelevant of the time of year. For the human body to produce vitamin D from the sun it must be at least above 40 degree declination. What this means for the indoor tanner is that we have evolved to be exposed to different concentrations of the different types of UV light at different times. So variety as well as moderation is key. Any clear plastics or glass will have a filtering effect on it just as the atmosphere does. This is why we recommend the stand-up machines to anyone new to tanning.
Pros and cons of UVB exposure
- Except for type 1 skin it makes your skin produce more melanin that works like your natural sun-protection
- Make a tan gradually darker and more natural (delayed pigmentation)
- Makes a tan last longer
- Stimulates vitamin D production
- IARC (the International Agency for Research on Cancer) has concluded that regular and moderate sun-exposure reduces the risk of melanoma
- Overexposure will burn your skin and increase the risk for skin-cancer
UVA rays have the longest wavelength of 320-400 nanometers so it makes up about 95 percent of the light reaching the earth’s surface (FYI even suncreams struggle to filter out much of the UVA which makes it harder to monitor exposure). They are 30 to 50 times more prevalent. The tanning effects of UVA are more immediate than UVB as it simply darkens the pigment. It also differs from UVB in the sense that it always present in high quantities all year round and any time of day.
Pros and cons of UVA exposure
- Oxidizes the melanin into a darker colour which adds to the natural sun-protection
- Will create a fast and dark tan for tanners with existing melanin (immediate pigmentation of skin-type 3 and darker)
- A UVA-tan only disappears quickly
- Does NOT make your body make vitamin D
- Increases the photo-damage to your skin (photo-aging)
- Exposure mainly to UVA does not mean any reduced risk for skin-cancer.