Which substance is primarily responsible for the depletion of the ozone layer, leading to harmful effects such as lung cancer and DNA damage in humans?

Explanation

Ozone layer depletion is mainly caused by chlorofluorocarbons (CFCs). These compounds break down ozone molecules in the stratosphere, increasing the risk of harmful ultraviolet radiation reaching the Earth, which can lead to lung cancer and DNA damage. Other gases like CO2, SO2, and hydrocarbons do not significantly contribute to ozone layer depletion.