Alveolar macrophage count as an indicator of lung reaction to industrial air pollution.

The major proportion of the cellular components found in most of the sputa from persons working in polluted atmospheres are alveolar macrophages, and counts of the alveolar macrophages present in smears made from sputa from exposed workers probably reflect the lung reaction to air pollution. An investigation of this phenomenon was undertaken using the sputa of workers in different types of industries: a coke plant, two different aluminum reduction plants, a ship-building yard and asphalt work on a road. The results showed that the alveolar macrophage count increases with a higher level of particulate pollution in the workplace. A synergistic effect of occupational air pollution and smoking habits was also recorded.