Woodsmoke Particulate + Hypertonic Saline

Deployment of military personnel has been associated with increased respiratory illness likely due, in part, to inhalation of unusual particulate matter (PM), such as from burn pits. Inflammation is a key initial response to inhaled particulates. The investigator has developed a protocol using inhaled wood smoke particles (WSP) as a way to study PM-induced airway inflammation. Exposure to wood smoke particles causes symptoms, even in healthy people, such as eye irritation, cough, shortness of breath, and increased mucous production. The purpose of this research study is to see if a single treatment of inhaled hypertonic saline (HS) can diminish this PM-induced airway inflammation by rapidly clearing the WSP inhaled particles from airway surfaces. The exposure will be 500 ug/m³ of WSP for 2 hours, with intermittent exercise on a bicycle and rest. The wood is burned in a typical wood stove and piped into the chamber.