The only way to truly test if a variable is undefined is to do the following. Remember, undefined is an object in Javascript. To determine if a variable or object property exists, It is good to compare to keyword undefined or you can also check the type of the object to string âundefinedâ. In the following JavaScript code we compare the num to the undefined in both way.
Nuclear waste -- The waste from nuclear power plants will be toxic for humans for more than 100,000 years. Itâs untenable now to secure and store all of the waste from the plants that exist. To scale up to 2,500 or 3,000, let alone 17,000 plants is unthinkable.
Exposure to radioactive waste may cause serious harm or death. In humans, a dose of 1 sievert carries a 5.5% risk of developing cancer, and this risk is assumed to be linearly proportional to dose even for low doses. Ionizing radiation causes deletions in chromosomes. lot of this waste is alpha particle-emitting matter from the decay chains of uranium and thorium. The main source of radiation in the human body is potassium -40 (40K), typically 17 milligrams in the body at a time and 0.4 milligrams/day intake. Most rocks, due to their components, have a low level of radioactivity.