You cannot see, smell or taste radon. It is extremely radioactive, emitting alpha radiation as it decays. Once inside the lungs, delicate tissues can be genetically damaged by radon decay products, and this can lead to the development of lung cancer.
Radon is one of the most significant environmental health risks today, responsible for an estimated 3,200 deaths every year in Canada. Recent estimates published by the Radiation Protection Bureau of Health Canada show that 16% of lung cancer deaths are attributable to indoor radon exposure. This estimate is conservative and will increase as radon induced lung cancers are more commonly detected in the future.