The ozone layer is an invisible layer of protective gases that are around the Earth. The ozone layer stops most of the harmful ultraviolet rays that constantly bombard the Earth.

Ozone is a pale blue gas. It is a form of oxygen. The common form of oxygen is a gas that all animals and humans need to breathe in order to survive. But ozone is poisonous and explosive. It differs from ordinary oxygen in its chemical composition. Each molecule of ordinary oxygen has two atoms (small invisible constituents). Each ozone molecule has three atoms.

Ozone is often produced when charged by electricity, such as lightning that passes through the air. People sometimes notice the smell of ozone after a thunderstorm or around electrical equipment. The earth is covered with an air blanket called “atmosphere”, which consists of several layers. Ozone is a natural part of the Earth’s upper atmosphere. About 19-30 kilometres above the Earth is a layer of gas called ozone, which is a form of oxygen. This part of the atmosphere is called the ozone layer. It protects people by absorbing harmful rays from the sun. If they reach Earth, these rays can cause skin cancer, eye diseases and other health problems.

Some chemicals used in industry can destroy this protective ozone. Scientists have discovered a “hole” in the ozone layer over Antarctica. To preserve the ozone layer, many countries have restricted the use of destructive chemicals.

Although ozone is beneficial high above the Earth, it is harmful near the earth’s surface. Even very small amounts in the lower atmosphere can irritate people’s eyes and cause coughing. Car exhaust combined with sunlight can increase the amount of ozone in the air. People in many big cities suffer from health problems caused by high levels of ozone.

What is an ozone hole?

Every spring, a whole the size of the United States forms in the ozone layer over Antarctica, at the South Pole. Every year, a smaller hole forms over the Arctic, at the North Pole. And there are signs that the ozone layer is becoming thinner across the planet.

Scientists have discovered that the ozone hole over Antarctica began in 1979 and that the ozone layer as a whole began to deplete in the early 1980s.

Ozone depletion occurs when more ozone is destroyed than nature creates.

What causes the ozone hole?

One group of gases damages the ozone layer. These gases are called CFCs, Chloro-Fluoro-Carbons. CFCs are used in some spray cans to push the contents out of the can. They are also used in deodorants, fragrances, refrigerators, air conditioning systems and some fire extinguishers. They are used because they are non-toxic and non-flammable. Most countries have already stopped using these substances (CFCs and aerosols). In one of the largest cities in Canada, Montreal, between many countries in the world, an agreement is signed to reduce the use of aerosols.

UV rays are rays that the Sun sends to the Earth. They can cross the water and kill small aquatic animals or plants called plankton, which form the basis of the food chain in the oceans and seas. Whales and other fish use plankton as their main food, and if plankton dies from these UV rays, whales will also begin to die because they will have nothing to eat. Large amounts of UV rays can damage all green plants. If the ozone layer continues to become thinner, the plants on Earth will decrease, then there will be less food in the world.

The ozone layer is like sunscreen and thinning it would mean that more ultraviolet rays will reach us. Too much UV would cause more sunburn. These UV rays are also dangerous to our eyes and can increase people’s blindness. That is why sunscreen and sunglasses are very important.