- What ozone-depleting substances are
- Where ozone-depleting substances come from
- How ozone-depleting substances can affect our health
What ozone-depleting substances are
Certain chemicals (such as chlorofluorocarbons, hydrochlorofluorocarbons and halons) are recognized as ozone-depleting substances (ODS) because they breakdown in the stratosphere and release chlorine or bromine, which destroy the stratospheric ozone layer. Most ODS are also greenhouse gases.
Where ozone-depleting substances come from
The most common uses of ozone-depleting substances are as refrigerants in commercial, home and vehicle air conditioners and refrigerators, foam blowing agents, solvents, aerosol spray propellants, fire extinguishing agents and chemical reactants.
How ozone-depleting substances can affect our health
The ozone shield screens the earth from some of the sun's harmful ultraviolet rays - UVB. As that layer is depleted, higher UVB levels are present.
Increased exposure to UVB can cause skin cancer and plays a major role in malignant melanoma development. Overexposure to UV radiation may also suppress proper functioning of the body's immune system and the skin's natural defences. UV radiation can also increases the likelihood of cataracts, a form of eye damage in which a loss of transparency in the lens of the eye clouds vision. If left untreated, cataracts can lead to blindness.
Ozone depletion and climate change are both mainly caused by changes in the atmosphere due to human activities. Global warming is due to the build-up of heat-trapping gases in the atmosphere and is not caused by ozone depletion. Some chemicals which deplete ozone, such as CFCs, also trap heat in the atmosphere and contribute to global warming.