Ultraviolet (UV) radiation is one type of energy, or radiation emitted from the sun. Some exposure to sunlight is beneficial. For example, sunlight is a good source of Vitamin D for the body. However, too much exposure to UV radiation can be dangerous and cause a variety of problems.
One danger that may occur from UV radiation is damage to the skin. The skin has three layers, the epidermis, the dermis and the subcutaneous fat. Exposure to UV light can lead to a sunburn, which causes redness, burning and pain to the epidermis layer of the skin. The UV rays can also penetrate the dermis, which is the deeper layer of the skin. This can cause damage to the cell membranes and may lead to skin cancer.
There are three main types of skin cancer including basal cell, squamous cell and melanoma. All three types are associated with sun exposure. Basal and squamous cell skin cancer tend to be localized and are less serious than melanoma, which is the deadliest type of skin cancer.
Although not deadly, other skin changes can be caused by UV radiation. The UV light contributes to aging of the skin, including wrinkles and lines. It can also cause brown spots and dry skin.
Dangers of UV radiation are not limited to the skin. Too much exposure to UV light can cause a condition know as photokeratitis, which is a burn to the cornea in the eye. The condition causes pain, but usually not permanent damage. However, damage from too much exposure to UV radiation is considered a risk factor for developing cataracts, which is a serious eye condition that can lead to blindness.
There are ways to reduce the dangers of UV radiation. The UV index is a rating system developed to inform the public of the intensity of UV rays on any given day in any location. The index rates the strength of the UV rays on a scale of one to ten and lists how many minutes of sun exposure would cause a sunburn. It provides an estimate to help people gauge how long they can safely stay in the sun. The index is published in newspapers and broadcast on many television news reports.
In addition to being aware of the UV index, individuals can protect themselves from the dangers of UV radiation by avoiding being in the sun when the rays are at their strongest. This is usually between 10AM and 3PM. Sunscreen with an SPF of 15 to 30 should be applied prior to going outside. Sunglasses and wide-brimmed hats may also block UV rays.