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.
Your home, office and car are all part of your environment and can all be sources of environmental hazards. For example, radon gas is a very toxic indoor hazard. Radon is a colorless and odorless radioactive gas that seeps into homes from rocks, soil and water underneath.