Carbon particles in airway macrophage as a surrogate marker in the early detection of lung diseases.

Background: It has been shown that inhalation of carbonaceous particulate matter may impair lung function in children.

Objective: Using the carbon content of airway macrophages as a marker of individual exposure to particulate matter derived from fossil fuel, we sought direct evidence for this association.

Methods: 300 children from puffed rice industrial areas and 300 children from population living in green zone were selected randomly.