Modes of Exposure

Lead enters the body in the largest doses through inhalation. Breathing in lead dust during construction can quickly lead to exposure beyond the permissible levels. Once inhaled, the lead dust enters the respiratory tract and becomes absorbed into the bloodstream.

Lead can also enter the bloodstream by ingestion. Swallowing small amounts of saliva contaminated with lead dust, or eating, drinking, or smoking in the presence of lead dust or fumes, can send the lead to the digestive tract. Once the lead is in the digestive tract, it is then absorbed into the bloodstream.

Once lead is in the bloodstream, it circulates throughout the body, entering organs, tissues, and bones. Some of this lead is quickly filtered out of the body, but some of it remains stored in the body, often for years. This is especially true if a worker continues to absorb lead faster than his or her body excretes it. Since the body holds on to the lead, sometimes for years, an individual may not always experience the symptoms of lead poisoning right away. As the lead is released from the bones and tissues, it causes irreversible damage, first to individual cells, and then to entire organs.

Lead dust can also settle on hair and clothing, making it possible for a worker to track lead back home, potentially exposing the entire family. Pregnant women, infants, and children are at particular risk for lead poisoning.

To learn more about Construction Lead Exposure visit our Cal/OSHA Construction Lead Exposure Online Training web page.