Question

tobacco smoke and formaldehyde are dangerous indoor pollutants. which of these is also a dangerous indoor air pollution? radon gas oxygen gas

Explanation:

Radon gas is a radioactive gas that can seep into buildings from the ground. It is a known carcinogen and a dangerous indoor air pollutant. Oxygen gas, on the other hand, is essential for life and not a pollutant.

Answer:

Radon gas