What is the primary route of lead entry into the human body?

The primary route of lead entry into the human body is through inhalation and ingestion. This occurs when lead-containing dust or particles are inhaled or when individuals consume contaminated food or water. Young children are particularly at risk because they may put their hands or objects contaminated with lead into their mouths, increasing the likelihood of ingestion.

Inhalation can occur in environments where lead is present in the form of dust, fumes, or particles, such as during certain industrial processes, renovation activities involving lead-based paints, or in areas contaminated with lead from previous uses like leaded gasoline.

While skin absorption is possible, it is not considered a significant route of lead exposure compared to inhalation and ingestion. Injection is not a common route for lead exposure in typical environmental contexts. Although digestion is a part of the ingestion process, it does not encompass the inhalation aspect, which is crucial for understanding the primary ways lead enters the body. Thus, the combined routes of inhalation and ingestion are the most critical pathways for lead exposure.