Testing for mutagens in an aluminium plant. The results of Salmonella typhimurium tests on expectorates from exposed workers.

Methanol extracts of hydrolyzed expectorate samples from workers in a Söderberg potroom were evaluated by the Salmonella reversion assay. The expectorates from exposed workers--mostly from smokers, but also to a certain extent from nonsmokers--were mutagenic; however, the control samples from both smokers and nonsmokers were not. The positive results produced by the expectorate samples from the exposed smokers suggest a synergistic relationship between exposure to air pollution of the working atmosphere and smoking.