summary no.3_TYAS SAMESTY

Positive and negative effects of Ultraviolet Light. The positive effect of ultraviolet light that can cure certain skin diseases, kills bacteria, detect counterfeit money, vitamin form, ultraviolet rays can also harm humans on several occasions. To the knowledge of all people, the direct effects of light on the eye for an excessive period of time can cause blindness, Although can cure certain skin diseases, ultraviolet rays can cause skin cancer and ultraviolet rays from the sun has been classified as cancer-causing agent third most dangerous after alcohol and tobacco.