When summer is here, few activities are more relaxing than lounging by the pool under the bright sun. Yes, you probably know that too much exposure to the sun’s ultraviolet light can increase your risk for skin cancer as well as give you a nasty sunburn. But bathing in the sun also provides real benefits, like boosting the production of Vitamin D in your body, which helps strengthen bones, improve your immune system, and even fight depression.
So how much sun is too much? That determination depends on three things: Your location, the time of day, and your skin type.
All other things being equal, you know there’s a big difference between sunbathing in Copenhagen and slathering up in Cancun. The closer your location is to the equator, the more intense the sun, thus the more ultraviolet radiation that will bathe your body.
But it’s not just latitude that matters. Australia and New Zealand are located close to a hole in the ozone layer. A thinner ozone layer allows in more ultraviolet light, attributing to higher radiation levels in these areas.
Altitude can make a difference, as well, with higher elevations receiving higher radiation indexes.
Measuring UV Radiation
To take into account these different exposures, an international standard has been developed for measuring UV radiation at a certain location. The UV index for your area is available with a quick internet search.
- UV index 0-2 is considered low exposure
- UV index 3-5 is considered moderate exposure
- UV index 6-7 is considered high exposure
- UV index 8-10 is considered very high exposure
- UV index of 11+ is considered extreme exposure
The general rule of thumb is that when the UV index is 3 or above, you should use sun protection for any length of exposure, including sunglasses, protective clothing, and sunscreen.
Time Of Day
Your mother was right when she told you to come out of the sun at the height of the day. Because the sun moves across the sky, the UV index will vary by hour. Note that most sources report the UV index of your location for twelve noon, the theoretical time of full exposure. Early mornings and late evenings will have a lower UV index, allowing you more healthy time in the sun.
Keep in mind that sand, snow, and water also reflect UV light. If you’re at the beach or a sunny lake, be sure to take that increase into account when determining how long you want to bask.
Fair-skinned, freckled people prone to sunburn have to take more care when it comes to sun exposure than those with olive-tone or darker skin. Those with darker skin and who are more prone to tan than to burn can enjoy up to thirty minutes before they really need to slather on sunscreen. The fairest among us shouldn’t spend more than ten to fifteen minutes a day exposed to direct sunlight without some sort of protection.
Fortunately, even these short time spans suffice to gain the benefits of sun exposure. Scientists have reported that twenty- to twenty-five minutes of careful daily exposure, like a quick walk in the park in short-sleeves, will get your body producing all the Vitamin D it needs.
The rest of the time, be sure to protect yourself by slathering up well.