Which ozone type is protective?

Which ozone type is protective?

• A. Ground-level ozone
• B. Stratospheric ozone
• C. Tropospheric ozone
• D. None of the above

Answer: (B)

Ozone in the stratosphere forms the protective layer that absorbs most of the Sun’s ultraviolet radiation, especially UV-B and UV-C, shielding living beings from DNA damage, skin cancer, and other harmful effects. That protective role makes stratospheric ozone the correct answer. The ozone found near the ground or in the lower atmosphere—ground-level ozone or tropospheric ozone—comes from photochemical reactions involving pollutants and sunlight and is harmful to health and ecosystems; it isn’t protective.

Ozone in the stratosphere forms the protective layer that absorbs most of the Sun’s ultraviolet radiation, especially UV-B and UV-C, shielding living beings from DNA damage, skin cancer, and other harmful effects. That protective role makes stratospheric ozone the correct answer. The ozone found near the ground or in the lower atmosphere—ground-level ozone or tropospheric ozone—comes from photochemical reactions involving pollutants and sunlight and is harmful to health and ecosystems; it isn’t protective.