An overdose of numbing medications can cause fatal side effects if too much of the medicine is absorbed through your skin or gums and into your blood. This is more likely to occur when using a numbing medicine without the advice of a medical doctor (such as during a cosmetic procedure like laser hair removal).
Largest Beaver Dam Seen From Space. The dam in northern Canada spans 2,800 feet and has likely been under beavers' construction since the mid-1970s. A Canadian ecologist has discovered the world's largest beaver dam in a remote area of northern Alberta, an animal-made structure so large it is visible from space. Researcher Jean Thie said Wednesday he used satellite imagery and Google Earth software to locate the dam, which is about 850 meters (2,800 feet) long on the southern edge of Wood Buffalo National Park.
In the U.S., the most common type of dam is the embankment dam. These are large dams made out of soil and rock which use their weight to hold back water. To prevent water from moving through them, embankment dams also have a thick waterproof core. The Tarbela Dam in Pakistan is the worldâs largest embankment dam. Finally, gravity dams are huge dams that are constructed to hold back water using only their own weight. To do this, they are constructed using extensive amounts of concrete, making them difficult and expensive to build. The Grand Coulee Dam in the U.S. state of Washington is a gravity dam.