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 the major component of steel, with carbon being a distant second, at between 0.2% and 2.14%, depending on the grade. Carbon is the most cost-effective way to alloy iron, but other metals can be used to augment the element and to give the metal certain properties. The metal known as cast iron is actually steel that has a very high carbon content, which gives it a lower melting point and greater castability.