Ozone in the Atmosphere
Ozone is a colorless, volatile gas that exists in both the stratosphere (above the Earth's surface) and the troposphere (at or near the Earth's surface). In the stratosphere, it protects people from harmful ultraviolet radiation from the Sun. In the troposphere, it is a climate pollutant that occurs naturally when sunlight mixes with air pollutants including volatile organic compounds (VOCs) and nitrogen oxides (NOx).
The Stratospheric Ozone Layer
Ozone in the stratosphere absorbs most of the UV radiation from the Sun. Without this ozone, the Sun's intense UV radiation could sterilize the Earth's surface and cause skin cancer and eye damage.
Tropospheric Ozone
Ozone forms in the troposphere when sunlight interacts with hydrocarbons, including methane, and nitrogen oxides that are emitted by vehicles, power plants, and other man-made sources. These pollutants can remain in the atmosphere for hours or weeks and are often transported over long distances.
It is important to reduce the amount of ozone in the troposphere as it is a very harmful climate pollutant, causing skin cancer, eye damage, and other health problems. This is achieved by reducing emissions of methane and other ozone-forming chemicals, such as nitrogen oxides from fuel combustion.
The Ozone Action Day
The EPA publishes the Ozone Action Day when levels of ozone pollution are unhealthy for certain groups of people, including children, the elderly, and people with respiratory conditions such as asthma. This is to help people understand the risks of breathing ozone and make sure they take the necessary steps to avoid the pollution.
Health Effects of Ozone
Breathing ozone can cause coughing, throat irritation, congestion, and chest pain. It may also worsen bronchitis, emphysema, and asthma. It can even permanently scar lung tissue.
Several studies have shown that repeated exposure to "bad" ozone can trigger inflammation of the linings of the lungs and cause permanent damage to lung cells. These results are not always predictable and depend on how often people breathe ozone and how much time they spend outdoors.
There is no safe level of ozone for human health. Exposure to high concentrations of ozone can cause headaches, burning eyes, and other symptoms.
Environmental Impact of Ozone
Ozone can also damage plant life, making the environment less healthy for humans and animals. When ozone forms in the ground, it can contaminate soil and water.
Ground-level ozone is especially bad for children, people with respiratory conditions, and anyone who does not have good lungs. It is most common in hot weather when people are outdoors, but it can occur during any time of year.
Ozone Generation and Treatment
Ozone can be produced by a number of different methods, such as ozone generators that use electricity to create ozone. These devices typically use a combination of a ground electrode and tubular high-voltage electrodes to produce ozone.
Some ozone generators are powered by solar energy, while others require a diesel engine or other fuel source to create the ozone. The ozone generated is then dispersed by spraying it on surfaces.
The ozone is then recycled back to diatomic oxygen using the reaction O3 + O2. It is this process that makes it a cost-effective and environmentally friendly way of treating drinking water.
