The Ozone Layer
What are some other effects of ultraviolet radiation?
Small amounts of ultraviolet (UV) radiation can actually be good for you because it aids in the production of Vitamin D in the body. However, you only need about 10 to 15 minutes of sunlight exposure a day to get this benefit (not getting enough sunlight leads to Vitamin D depletion, which can lead to depression and other symptoms in humans and is, indeed, a chronic problem in populations located in northern and extreme-southern climates).
Besides the risks of cancer—especially melanoma—overexposure to UV radiation can cause cataracts or inflammation of the cornea (“snow blindness”). If exposure is not too long, the eye can heal itself from this inflammation, but prolonged exposure could lead to permanent blindness; cancer of the eye is also a possibility. It is also believed that too much UV radiation weakens immune systems, though studies are still being conducted to more fully understand this health risk. Interestingly, it has also been found that, in areas where ozone levels are lower and more UV radiation penetrates to ground level, certain construction materials such as wood and some plastics degrade at a higher rate than normal.
High UV levels also, of course, affect plants and animals, though some are at a higher risk than others. Scientists have learned, for example, that soy bean crops and some types of rice could die if the ozone were too severely depleted. Also, young pine tree needles are damaged by UV light, but mature needles, which have a waxy coating, are protected. In the oceans, some forms of plankton could die or be severely depleted if the ozone was not doing its job. The result would be a breakdown in ocean food chains that could be devastating. The effects on wild animals are not well known, though nocturnal animals would likely be unaffected, and many diurnal animals have fur or feathers that protect them from radiation. However, skin around the eyes and ears are often more exposed to the sunlight, and animals would be as susceptible to eye problems as much as humans.