More than 90 percent of total body burden of lead is accumulated in the bones, where it is stored for decades. Lead in bones may be released into the blood and re-exposes organ systems long after the original environmental exposure. This process can also expose the fetus to lead in pregnant women. Lead is commonly added to industrial paints because of its characteristic to resist corrosion. Oral ingestion may represent a major route of exposure in contaminated workplaces.
Most exposures occur with inorganic lead.
Organic forms may be absorbed through the skin, while inorganic forms cannot. The toxic nature of lead is well documented. The frequency and severity of symptoms among exposed workers depend upon the level of exposure. Leaded gasoline emissions are the main contributor to airborne lead levels. Food made and sold in the USA generally has low lead levels.