Beach survival tips: what's summer without a trip to the beach? But basking the scorching sun has its pitfalls.
SAVE YOUR SKIN
Baking in the sun is a recipe for disaster! Erythema, or sunburn, is caused by a type of skin-damaging light called ultraviolet B, or UVB. Deeper-penetrating UVA rays cause premature skin aging. And both lead to skin cancer, a condition that spurs uncontrolled cell growth. The nastiest kind, malignant melanoma, begins in melanocytes, cells that give your skin color. Since 1930 this cancer has become 1,800 percent more common, says the U.S. Environmental Protection Agency Why? Deterioration of ozone, a gas that hovers 15 to 40 kilometers (10 to 25 miles) above Earth, where it absorbs UVB light. A few sun safety tips: * Seek shade between 10 a.m. and 4 when the sun's rays are strongest * Learn your local UV index (see chart), a sun-severity forecast listed in many newspapers * Always wear broad-spectrum sunscreen (lotion with chemicals that absorb and reflect both UVA and UVB rays) labeled SPF 15 or higher. Even on cloudy days, 80 percent of UV rays still reach Earth.
EYE FOR SAFETY
"Some people think the darker the lens, the more UV protection," says ophthalmologist Andrew Iwach at the University of California, San Francisco. But, in fact, unless lenses feature protective UV-coating, dark shades can increase your exposure to harmful UV rays! Here's how: Shades block light, so your pupils open to let more light in. UV rays bombard the clear cornea on the eye's surface and the retina, a light-sensitive membrane at the back of the eye. This can lead to vision-clouding cataracts and macular degeneration (retina damage that is the main cause of blindness in people over age 65). So for your eyes' sake, choose shades with 100 percent UV protection.
BEAT THE HEAT
Beach volleyball, anyone? Physical activity in scorching summer heat can stoke your body temperature above its normal 37 [degrees] C (98.6 [degrees] F). You respond by sweating: as moisture evaporates into the air, it whisks heat from your skin, cooling you down. But humid weather slows evaporation. And exercising in extreme heat can make you sweat more than a quart an hour, depleting your body of water and salt. When the sweat system stops functioning, body temperature can skyrocket upward of 40 [degrees] C (104 [degrees] F): a life-threatening condition called heatstroke, which claims 300 lives annually. Initial symptoms: flushed skin, headache, rapid pulse, loss of consciousness. Prevent disaster: * Drink at least one cup of water for every half-hour of exercise. * Avoid alcohol and caffeine--both substances dehydrate the body. * Avoid midday exercise when heat peaks. * Wear light-color fabric--it absorbs less heat.
Hot dry sand can inspire sole-burning footwork. But the same sand frying your feet is cool just inches beneath the surface. "That's because air doesn't conduct heat well," says atmospheric scientist Peggy LeMone of the University Corporation for Atmospheric Research, Conduction occurs when energy transfers from one molecule to another, "and air spaces between dry sand grains work like insulation." So heat from sunlight on the surface can't penetrate deep into sand. Since you have to step on the hot surface, wear flip-flops to prevent scorched feet and puncture wounds caused by beach debris--like shells and litter from broken glass and soda cans.
Did You Know?
* A good reason to begin sun protection at an early age: most people receive 80 percent of their lifetime sun exposure by age 18. and today, one in five Americans develops skin cancer, mostly due to overexposure to the sun's harmful UV rays.
Environmental Studies: When did scientists first notice the depletion of the ozone layer? Research and report on the causes.
CHECK FOR UNDERSTANDING
Directions: Use the chart to answer the questions below.
1. If you usually burn and the UV index reads 7, how long does it take to burn your skin?
2. If you always burn and the UV index reads 8, when will your skin start to burn?
3. When should you use a sunscreen? Why?
4. On a separate piece of paper make a graph showing the UV index and the minutes it takes for the sun to burn your skin.
Bonus: You're heading to the beach. Cite at least five items you'll need to bring for sun protection.
1. It takes approximately 25 minutes for skin to burn.
2. Skin begins to burn after approximately 10 minutes.
3. Always wear a broad-spectrum sunscreen labeled SPF 15 or above. Even on cloudy days, as much as 80 percent of UV rays still reach Earth.
Bonus Answers will vary but may include the following: broad-spectrum sunscreen labeled SPF 15 or higher, beach umbrella, flip-flops, water, UV-proof sunglasses, wide-brim hat, light-color clothing.
National Science Education Standards
Grade 5-8: structure and function in living systems * transfer of energy * personal health * risk and benefits * structure of the Earth system
Grade 9-12: the cell * conservation of energy and the increase of disorder * interactions of energy and matter
Check out the U.S. Environment Protection Agency for sun-safety activities: www.epa.gov/sunwise/index.html
For older students, learn more about ultraviolet light and ozone depletion at www.epa.gov/ozone/resource/public.html
For swim safety tips visit the United States Lifesaving Association: www.usla.org/PublicInfo/safety.shtml
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|Article Type:||Brief Article|
|Date:||May 6, 2002|
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