Heart palpitations can be triggered by stress, exercise, medication or, rarely, a medical condition. Although heart palpitations can be worrisome, they're usually harmless. In rare cases, heart palpitations can be a symptom of a more serious heart condition, such as an irregular heartbeat (arrhythmia), that may require treatment. Symptoms.
Long-term exposure to radon can lead to lung cancer, the only cancer proven to be associated with inhaling radon. There has been a suggestion of increased risk of leukemia associated with radon exposure in adults and children; however, the evidence is not conclusive.
At levels normally encountered in the environment, radon exposure causes no acute or subacute health effects, no irritating effects, and has no warning signs. 1  The primary adverse health effect of exposure to increased levels of radon is lung cancer. 2  For lung cancer to develop may take years.