Routes of entry into the body
Industrial Toxicology

The lungs are the main route of entry for xenobiotics (substances foreign to the body). They are characterized by :

• large exchange surface area: alveolar surface area ≥ 100 to 150 m² ;

• a thin alveolar wall and strong vascularization;

• a high volume of gas exchange.

The volume of air inspired by physical activity for workers is :

• at rest ≥ 6 L/min ;

• during moderate work ≥ 20 L/min ;

• during intense work ≥ 100 L/min.

To determine human exposure to xenobiotics, an average of 8 to 10 m³ of inspired air is used in a normal 8-hour working day, and a total of 15 to 20 m³ over a 24-hour day.