Air pollution is a major concern for environmentalists, governments and individuals worldwide. It has been linked to a range of health issues, including skin cancer, cardiovascular disease and asthma. One particularly harmful group of pollutants are the chlorofluorocarbons (CFCs), which have been banned from use in products like aerosol sprays and foam blowers. CFCs are known to contribute to ozone depletion by breaking down ozone molecules in the stratosphere, and their destruction allows more ultraviolet (UV) radiation to reach Earth’s surface, causing harm to plants and people.
The ozone depletion caused by CFCs is part of a process called catalytic ozone destruction, which occurs when UV radiation breaks down the chlorine atoms in ozone molecules. The free chlorine atoms then react with other oxygen atoms to destroy ozone molecules. This process is repeated over and over again, resulting in a hole in the ozone layer and allowing harmful UV radiation to reach Earth’s surface.
CFCs are also a significant contributor to the formation of smog, a toxic haze that is composed of ground-level ozone and particulate matter. Smog can irritate respiratory systems and damage crops, and is especially harmful for children and the elderly.
The gases that make up smog are created when primary air pollutants such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight. Vehicle exhaust, power plant emissions, and the burning of fossil fuels all produce NOx and VOCs, which can then interact with sunlight to form ground-level ozone.