The Iodine Story Nature's Essential Element

Iodine is a chemical element with the symbol I and atomic number 53. It is a member of the halogen group in the periodic table, characterized by its highly reactive and electronegative properties. Iodine is a nonmetallic, diatomic molecule that appears as a lustrous, purple-black solid at room temperature and sublimes easily to form a violet gas with a distinctive odor.

Naturally occurring iodine is primarily found in the ocean and in soil in coastal areas, where it is absorbed and concentrated by seaweed and other marine organisms. It is essential for human health as a key component of thyroid hormones, which are critical for regulating metabolism, growth, and development. Due to its importance in nutrition, iodine deficiency is a significant health issue in many parts of the world, leading to the implementation of iodization programs, where iodine is added to table salt to ensure adequate intake.

Iodine has several industrial and medical applications. It is used in the manufacture of disinfectants, antiseptics, and pharmaceuticals, including iodine tincture and iodophors, which are commonly used for sterilizing wounds and surgical equipment. In analytical chemistry, iodine is utilized in various tests and reactions, such as the iodine-starch test to detect starches. Additionally, radioactive isotopes of iodine, particularly iodine-131, are used in medical diagnostics and treatments, especially for thyroid conditions and cancers.

The element is extracted from iodine-containing minerals or produced commercially by processing brine from oil and gas fields, where iodine is a by-product. Despite its widespread use and importance in health and industry, iodine must be handled with care due to its corrosive effects and potential toxicity in high concentrations.