what is the main cause of ozone layer depletion

The main cause of ozone layer depletion is the release of man-made chemical compounds containing chlorine and bromine, primarily chlorofluorocarbons (CFCs). These compounds are used in products like refrigerators, air- conditioners, solvents, and aerosol sprays. When these chemicals reach the stratosphere, they are broken down by ultraviolet (UV) radiation, releasing chlorine and bromine atoms that react with ozone molecules, breaking them apart and thinning the ozone layer. A single chlorine atom can destroy up to 100,000 ozone molecules. Other substances contributing to ozone depletion include halons, carbon tetrachloride, hydrochlorofluorocarbons (HCFCs), methyl chloroform, and methyl bromide. Additionally, unregulated rocket launches and nitrogenous compounds also play a role, but CFCs are the most significant contributors to ozone layer depletion. This depletion is harmful because it allows more UV radiation to reach Earth's surface, causing health issues such as skin cancer, cataracts, and immune system suppression, as well as adverse effects on animals, plants, and marine life. International efforts like the Montreal Protocol, established in 1987, aim to reduce and eliminate the use of ozone-depleting substances to protect the ozone layer. In summary, the dominant cause of ozone layer depletion is CFCs and other chlorine- and bromine-containing human-made chemicals.