What are the different effects of radon exposure?

Lung cancer: Radon is a radioactive noble gas that is naturally found in the ground. Exposure (excessive) to radon has been linked to the development of lung cancer. If you are talking about mega exposures such as at times of nuclear blasts, then you will get multiple radiation sickness, a syndrome that features multiple organ involvement and dose dependent effects.

Expect no effects: When "radon-proofing" homes became a big-money trade, politicians got involved to force people to pay hard-earned dollars. The political claim that radon kills 40,000 people yearly was based on a totally false "linear" assumption about cancer. No one's demonstrated any effect in non-smokers, and even in smokers, it's low. I'd stop worrying and live healthy.