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 exposure can cause lung cancer. EPA estimates that there are approximately 21,000 annual radon-related lung cancer deaths in the U.S. every year, second only to tobacco smoke. The combination of radon exposure and smoking can greatly increase your chances of developing lung cancer.he results of a radon test will give you the level of your homeâs indoor radon level. EPA recommends that action is taken to reduce the radon level in your home if the test results are 4pCi/L or higher.