1. Stratospheric Ozone: Ozone in the stratosphere, about 15-35 kilometers above the Earth's surface, is beneficial. It forms a layer that shields the Earth from harmful ultraviolet (UV) radiation from the sun, protecting humans, animals, and plants from its damaging effects, including skin cancer and cataracts.

2. Disinfection: Ozone is used as a disinfectant due to its strong oxidizing properties. It is commonly used in water purification plants to kill bacteria, viruses, and other microorganisms. Ozone rapidly breaks down, leaving no harmful residues behind.

3. Air Purification: Ozone is employed in air purification systems to remove pollutants, including volatile organic compounds (VOCs), odors, and microorganisms. It is effective in reducing indoor air pollution.

Bad Ozone:

1. Ground-Level Ozone: Ozone at ground level, in the troposphere, is considered a harmful pollutant. It is formed when pollutants such as nitrogen oxides and volatile organic compounds react in the presence of sunlight. Ground-level ozone can irritate the respiratory system, causing coughing, wheezing, and shortness of breath. It can also worsen respiratory conditions like asthma and bronchitis.

2. Ozone Depletion: While stratospheric ozone is crucial for protecting the Earth from harmful UV radiation, human activities, particularly the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances, have led to the thinning of the ozone layer. This causes increased levels of UV radiation to reach the Earth's surface, posing risks to human health and the environment.

To summarize, ozone can have both beneficial and harmful effects on human health and the environment depending on its location in the atmosphere. Stratospheric ozone is essential for protecting the Earth from harmful UV radiation, while ground-level ozone is an air pollutant that can cause respiratory problems.