It was formed due to a reaction of alpha particles bombarded by bismuth. Astatine can be found in the atmosphere, but there is such a small amount of astatine in our atmosphere that it cannot be naturally harvested. Astatine has been proposed in the treatment of hyperthyriodism because it accumulates in the tyroid gland in humans. Hyperthyriodism occurs when the thyriod gland produces too much thyriod hormone, the hormone that controls bodily functions.
Hyperthyroidism causes tumors to grow on the thyroid gland.
There are now injections with astatine and iodine that can shrink the tumors to regular size. It has also been tested for possible treatment for toxic goiter. Astatine also has been found to cause pituitary cancer in laboratory rats. Astatine is one of the rarest elements in nature. The properties of Astatine are similar to Iodine.