You may need a backup method of birth control if you have vaginal intercourse during the seven days after a missed pill. Some backup methods are the condom, female condom, diaphragm, or sponge. You can also use emergency contraception (morning after pill) up to five days after unprotected intercourse.
Strontium-90, a radioactive isotope, is a by-product of nuclear reactors and present in nuclear fallout. It has a half-life of 28 years. It is absorbed by bone tissue instead of calcium and can destroy bone marrow and cause cancer. However, it is also useful as it is one of the best high-energy beta-emitters known. It can be used to generate electricity for space vehicles, remote weather stations and navigation buoys.
Strontium carbonate is also used to make certain kinds of glass and is the base material for making most other strontium compounds. Strontium-90, a radioactive isotope of strontium, is a common product of nuclear explosions. It has a half-life of about 28.8 years and decays into yttrium-90 through beta decay. Strontium-90 is especially deadly since it has a relatively long half-life, is strongly radioactive and is absorbed by the body, where it accumulates in the skeletal system.