2008 – Particles carry allergens deep into the lungs to be deposited

Very small particles, such as from diesel exhaust, have been shown to carry allergens deep into the lungs to be deposited in the delicate alveolar region. Studies have shown that alveolar macrophanges (scavenging cells) react to mite allergen by producing nitric oxide, which is a biomarker of inflammation in the lungs. This is a surprising event, because mite droppings are too large in size (10 to 50 microns) to enter the alveoli but instead settle on the bronchi. How the mite’s allergen entered the alveolar chamber has yet to be fully described, however, some scientists believe that the allergen seeps though the mite’s sealed dropping to contaminate objects nearby.