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.
Radon for Children. Harmful Effects of Radon. Radon is the second leading cause of lung cancer (diagram to the right) and a serious public health concern. The primary adverse health effect associated with chronic exposure to radon is lung cancer (typically bronchogenic): -squamous cell carcinoma. -small cell carcinoma.
The Health Effects of Exposure to Indoor Radon. Biological Effects of Ionizing Radiation (BEIR) VI Report. The National Academy of Sciences (NAS) on Thursday, February 19, 1998, announced the findings of its Biological Effects of Ionizing Radiation (BEIR) VI Report: The Health Effects of Exposure to Indoor Radon.. This report by the NAS is the most definitive accumulation of scientific data on indoor radon.