ABSTRACT
Situated within and just beneath the airway epithelium is a dense plexus of
sensory nerves. These sensory (afferent) nerves serve as sentinels at the gateway between the organism and the inhaled air. This airway mucosal
nerve plexus is present from the nose to the most peripheral airways. Irri-
tants in the polluted air interact with these sensory nerves initiating a cas-
cade of events that may lead to conscious sensations of irritation,
subconscious changes in autonomic neural control, and=or defensive
This manuscript has been reviewed and approved for release by the National Health
and Environmental Effects Research Laboratory, U.S. Environmental Protection
Agency. Approval does not signify that the contents necessarily reflect the views
and policies of the U.S. EPA, nor does mention of trade names or commercial pro-
ducts constitute endorsement or recommendation for use.
