Service Members who were deployed to the Persian Gulf region and Afghanistan (known as the Southwest Asia Theater of Operations) may have been exposed to airborne hazards from a variety of anthropogenic and environmental sources. There have been concerns that this population may be at increased risk of various respiratory illnesses, such asthma and constrictive bronchiolitis. The Department of Veterans Affairs has tasked an NASEM committee to examine the scientific evidence regarding exposure to these hazards during their deployment to this theater and respiratory health outcomes. The study will additionally identify gaps in knowledge and recommend actions to address them.