Metabolism of styrene by human liver and lung

In mice, styrene is pneumotoxic, and there is some evidence of tumorigenicity. This toxicity is thought to be related to its bioactivation to styrene oxide in lung. To determine if human tissues have this capacity, the metabolism of styrene to styrene oxide was measured in human liver and lung microsomal preparations. Hepatic microsomes metabolized styrene to styrene oxide, but lung microsomes had essentially no activity. However, microsomes from both tissues metabolized benzene to phenol. The data suggest that human lung has low styrene metabolizing activity and may be much less of a target organ than in mouse.