Alveolar macrophages from expectorates as indicators of pulmonary irritation in primary aluminum reduction plant workers

According to a method (the AM-test) previously developed by us, the counting of alveolar macrophages (AM) from expectorates provides an estimation of the potential pulmonary insult from occupational air pollution +/- smoking. In this article we demonstrate a relationship between the number of AM and self-registered pulmonary symptoms and complaints. Employees from different workplaces in a primary aluminum reduction plant gave expectorate samples for the AM-test. A gradient in the number of AM was observed, with increasing AM numbers from the controls to the administration employees to the potroom workers, who had the highest numbers. Pulmonary symptoms and complaints were recorded by means of a questionnaire. A clear covariation between AM numbers and respiratory symptoms and complaints was observed and was most pronounced at the highest pollution levels (in the potrooms). We therefore suggest that the AM-test may serve as an effect indicator as well as a dose indicator.