Radon gas is a naturally-occurring radioactive gas caused by the decay of uranium in the soil, and the amount in the environment depends on how much uranium is present in the soil nearby. Radon is toxic and can enter your home through the basement. Opening windows is one way to remove the radon.
Radon is most likely to occur in the basement and lower levels of a home because it originates from the soil. Radon can seep into a home through cracks in the foundation or other openings in the basement and lower home levels that are in contact with the soil. Radon can also exist in the air or inside some building materials, but the majority of radon in homes is from the soil.
Radon is a toxic gas that affects the lining of the lungs when it is inhaled and is the leading case of lung cancer in the U.S. after cigarette smoking. If home radon testing kits or professional radon testing have determined you have elevated radon levels in your home, you should fix the problem immediately.
Opening windows on the lower levels of your home can increase the ventilation, allowing radon to escape and for fresh air to come in, which reduces radon levels. However, this will not solve the problem of the radon entering your home in the first place, and you likely can't leave the windows open all the time.
You can take other preventative measures to remove radon in your home, including sealing up any cracks in the foundation to prevent more radon from entering the home. House pressurization, which is the act of fanning air from upstairs to the basement where the radon is, can also help remove excess radon in the home.