Earwax or even a piece of hair could be lying on top of the eardrum and when the eardrum vibrates, it may cause funny noises (just like a piece of string on a lightly beating drum). Obviously, treatment is by removal. Eustachian Tube Dysfunction can also cause crackling/popping noises.
Adverse Reactions to Elemental Iron Supplements Meeting your daily iron recommendation is important, and you may have to take supplements to get what you need. Iron's primary function is carrying oxygen through your blood and delivering it to cells, tissues and all of your organs.
Iron is also the most common element which forms the Earth (by mass), and it forms its inner and outer core Elemental iron is present in low-oxygen environments such as meteoroids, and it is reactive to water and oxygen. While fresh iron is silver-gray and lustrous, it gives iron oxides upon oxidation in normal air.