Maps, compasses, astrolabes, and calipers are among the early tools used by ocean navigators. In the modern era, these tools have been largely replaced by electronic and technological equivalents. Despite these early beginnings, it would take many centuries before global navigation at sea became possible.
Harmful Effects of Radon. 1  Radon is the second leading cause of lung cancer (diagram to the right) and a serious public health concern. 2  The primary adverse health effect associated with chronic exposure to radon is lung cancer (typically bronchogenic): -squamous cell carcinoma.
The only known health effect of radon is an increased risk of lung cancer. Radon does not cause any warning symptoms (like headaches, nausea, fatigue, or skin rashes), and if you are suffering from those symptoms or other physical ailments, you should consult your physician.