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.
Radon Symptoms. What are the symptoms of radon poisoning? Since radon is the #2 cause of lung cancer in the U.S., respiratory ailments are the most likely signs of radon-related distress. A persistent cough, hoarseness, breathing difficulties, and recurring respiratory infections are all possible indications of radon poisoning.