Health
There would be no life without the sun: sunlight is vital for our health. However, you should be attentive. The decrease of protective cover created by the ozone layer, and fashion for a tan can increase the risk for health. It is well-known that excessive exposing yourself to sunrays is extremely harmful. You should adhere to the golden mean.
The positive impact of ultraviolet rays on health
Ultraviolet rays contribute to the generating of vitamin D. This vitamin helps to absorb calcium and phosphorus, which strengthen bones and muscle tissue. Older people should regularly take hours of sunbathing. The best way is to arrange half-hour daily walks. Even if it is tiresome, short walks or simple sitting under the sun will be useful for them. When one gets older the body absorbs vitamins and calcium worse. Activity in the fresh air strengthens the body. Older people, who regularly take walks, fall ill rarely and their bones are in a better state.
Ultraviolet rays are also used in treatment for many diseases: rickets, psoriasis, eczema, jaundice.
The negative impact of ultraviolet rays on health
Excessive sunlight leads to various abnormalities. The most frequent of them is a sun stroke. Skin redness is actually a first-degree burn. The tan itself is a kind of damage, the skin thickens to protect from rays and gets older faster. Reaction of skin is manifested by birthmarks and pigment spots. This is an important sign, which should not be neglected! A direct consequence of sunrays' redundancy is skin cancer. Eyes can also suffer from the sun.
Studies of the recent years indicate that exposure to ultraviolet rays leads to a deterioration of certain functions of cells responsible for the work of the human immune system. This fact suggests that sun irradiation increases the risk of infection.
When does the intensity of ultraviolet radiation reach its highest level?
The higher rises the sun, the stronger is the ultraviolet radiation. Scud doesn't prevent from penetration of ultraviolet rays; they detain about 10% of radiation. Shadow reduces exposure by 50%. The ozone layer protects effectively against these rays, but its reduction increases their negative effect.