This page discusses the dual challenges of ozone (O3): its harmful excess in the troposphere, causing smog and health issues, and its depletion in the stratosphere, resulting in the ozone hole, partic...This page discusses the dual challenges of ozone (O3): its harmful excess in the troposphere, causing smog and health issues, and its depletion in the stratosphere, resulting in the ozone hole, particularly over Antarctica. This depletion, mainly due to chlorofluorocarbons (CFCs), increases UV radiation risks. However, international efforts, notably the Montreal Protocol, have reduced CFC usage and shown recovery signs in mid-latitude ozone levels, although the Antarctic hole remains an issue.