- Jonathan Patz / Marjorie Share
EcoHealth101 – www.ecohealth101.org
The Earth’s protective ozone layer is getting thinner. There’s less ozone to absorb harmful radiation from the sun, and more of this radiation is reaching the Earth’s surface. This affects our atmosphere – and our health.
Ozone is a form of oxygen. It generally forms when oxygen (O2) from near the Earth’s surface drifts high up into the atmosphere. Ultraviolet (UV) radiation from the sun hits the oxygen molecules.
Some molecules split apart, creating single atoms. These atoms sometimes link up with O2 molecules, forming a new molecule with three oxygen atoms. That’s ozone (O3).
Ozone can be helpful or harmful, depending on where it’s located. If it’s high up, it’s good ozone. Ozone in the stratosphere protects people, animals, and plants from harmful ultraviolet rays.
In 1985 scientists found a large ozone hole in the stratosphere over Antarctica. Each year the hole became bigger, letting more ultraviolet light through to the Earth’s surface. This situation is called stratospheric ozone depletion (SOD). Without the protection provided by ozone, we face a number of health problems.
The Other Face of Ozone
Ozone high in the stratosphere is good, but ozone near the ground is not. Do you ever hear "ozone warnings" on the weather report? Ozone can be very unhealthy.
Inhaling ozone can damage the respiratory tract, which enables us to breathe. Ozone also stunts plant growth. That hurts farmers, agriculture, and our economy.
How does ozone protect us?
Up in the stratosphere, ozone (O3) acts as a natural sunscreen to protect us against ultraviolet (UV) radiation. That’s the stuff that gives us sunburns. Because of the ozone layer, most of the harmful radiation never reaches Earth. But, as more and more of it does, we’re at greater risk for skin and eye problems.
People living near the Equator should be just as concerned about sun damage as people living where the ozone layer is thinning. The higher the sun is in the sky, the greater the direct sunlight reaching the Earth. Staying out of the sun when it is directly overhead (around noon hours), putting on sunscreen, and wearing a hat will help protect you.
What’s a "hot spot"?
The thinning of the ozone layer is not evenly spread around Earth. "Hot spots" are holes near the North and South Poles. People living in areas near the North and South Poles – including New Zealand, Australia, and the southern part of South America – are at extra risk of being harmed by ultraviolet radiation.