Ozone layer
The ozone layer is formed naturally in the Stratosphere.
It forms when ultraviolet (UV) rays from the Sun react with oxygen molecules.
Ozone is a gas made of three oxygen atoms (O₃).
The ozone layer helps absorb a large amount of harmful UV radiation.
Some UV rays still pass through the ozone layer and reach Earth.
When UV rays reach our skin, they can affect skin cells.
The body protects itself by producing melanin.
Melanin is the pigment that gives color to our skin, hair, and eyes.
Melanin is made by special cells called melanocytes.
Melanin absorbs part of the UV radiation.
By absorbing UV rays, melanin helps protect the DNA inside skin cells.
Melanin is stored in small structures inside skin cells.
When we stay in the sun, the body increases melanin production.
Increased melanin makes the skin darker.
This darkening of the skin is called tanning.
Tanning is a protective response of the body.
Melanin does not get used up like fuel.
The body keeps producing melanin when exposed to sunlight.
However, melanin does not block all UV rays.
Some UV rays can still reach deeper layers of the skin.
These rays can damage skin cells.
Damage can happen quickly, even before extra melanin is fully produced.
People with less melanin have less natural UV protection.
Their skin may burn more easily.
Sunburn can make the skin appear red or pink.
Redness happens because blood flow increases to the damaged area.
Even people with more melanin can experience skin damage.
Long exposure to strong sunlight increases risk of damage for everyone.
Sunscreen provides additional protection from UV rays.
Sunscreen works by blocking or absorbing UV radiation.
Protective clothing, hats, and shade also reduce UV exposure.
A genetic condition called Albinism causes very little or no melanin production.
People with albinism need strong sun protection.
Everyone, regardless of skin color, benefits from sun protection.
The body’s protective systems are helpful but not perfect.