【英语时差8,16】为何食盐中含有碘？2（在线收听）

 Before iodized salt became available, people living near seacoasts got adequate iodine because seawater and coastal soil contain iodine compounds. On the other hand, people living inland or in mountainous country tended to have iodine-deficient diets and a high incidence of goiter. After public-health investigators realized the connection between iodine deficiency and goiter, they looked for ways to insure that people living inland got the iodine they needed. The first iodized table salt was sold in Michigan in 1924. Iodized salt needs another additive, a stabilizer, to keep the potassium iodide from breaking down and releasing iodine into the air in the salt box, giving the salt a chlorine-like odor. The type of sugar known as dextrose will do the job, and is often used as an iodide stabilizer.