It can come from natural sources, such as sunlight, as well as artificial sources, such as lasers, black lights, and tanning beds. The sun is the most significant source of UV radiation. As a result, they can cause serious damage to all life forms.
Fortunately, UVC radiation is completely filtered out by the ozone layer. As a result, these rays from the sun never reach the ground. Man-made sources of UVC include welding torches, special bacteria-killing light bulbs, and mercury lamps. Although not considered a risk for skin cancer, UVC rays can cause severe damage to human eyes and skin, including burns, lesions, and ulcers on the skin.
A number of environmental factors can affect when UV rays are the most powerful. Some of these factors include:. UV exposure is highest between 10 a. This makes them more powerful. UV exposure is highest in the spring and summer months. During these seasons, the sun is at a higher angle, which increases UV ray intensity.
However, the sun can still affect you during fall and winter. UV exposure is highest in areas on or near the equator, where UV rays have less distance to travel before reaching the ground. The ozone layer provides protection from UV rays. But greenhouse gases and pollutants have caused the ozone layer to thin, increasing UV intensity. Clouds filter out some UV rays from reaching the ground.
The Food and Drug Administration requires all sunscreen to retain its original strength for at least three years. Check the sunscreen labels for directions on storing and expiration dates.
Throw away sunscreen if it's expired or more than three years old. Protect babies and toddlers. The American Academy of Pediatrics recommends using other forms of sun protection, such as shade or clothing, for babies under 6 months.
When that's not possible, apply sunscreen with at least 15 SPF to the face and back of the hands. The American Academy of Dermatology recommends not using sunscreen on children under 6 months. Keep them cool, hydrated and out of direct sunlight. If sun protective clothing and shade aren't available, consider using sunscreen on babies and toddlers. Use products that contain physical blockers titanium oxide, zinc oxide , as they may cause less skin irritation.
Is simply a ratio of the number of minutes that you can stay outside with the product on before getting minimal redness to the skin. And Dr. Dawn Davis, a Mayo Clinic dermatologist, says preventing that painful redness is one of the biggest factors in preventing skin cancer.
Davis recommends a minimum of SPF 30, which theoretically means you could stay protected from UV rays 30 times longer than without sunscreen. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version.
Overview Sunburn is red, painful skin that feels hot to the touch. Request an Appointment at Mayo Clinic. Skin layers and melanin Open pop-up dialog box Close. Skin layers and melanin Melanin is a natural pigment that gives your skin its color. You're heading to the pool or beach, and you stop to pick up some sunscreen. So how do sunscreen brands calculate an SPF? More Information Tanning: Does a base tan prevent sunburn?
Share on: Facebook Twitter. Show references Young AR, et al. Accessed April 22, Baron ED. Selection of sunscreen and sun-protective measures. Contact Us. Radiation Facts. Too much ultraviolet radiation UV from sunlight is dangerous. Nearly half of UV radiation is received between 10 a. Even on a cloudy day, you can be sunburned by UV radiation.
The U. Contact Us to ask a question, provide feedback, or report a problem. Causes sunburn. Causes tanning. Helps the body make vitamin D. Is more intense: During the middle of the day.
In the summer. At high altitudes and near the equator. Can cause skin cancer and cataracts. Protect your skin Protect your skin from too much sun when outdoors.
0コメント