Inhalation studies of Mt. St. Helens volcanic ash in animals : Respiratory mechanics, airway reactivity and deposition

ABSTRACT

This study was conducted to improve speculation of changes in breathing which might be expected while inhaling a dust like Mt. St. Helens volcanic ash. Effects of fine volcanic ash aerosol on pulmonary mechanical properties of awake Guinea pigs were evaluated during exposure by in halation. Ash penetration into the lung as well as tissue response to ash were determinated by transmission electron mycroscopy. The reactivity of airway epithelial irritant receptors following ash exposure was assessed using a histamine bronchoprovocation test. Airways of Guinea pigs exposed to ash were significantly less responsible to histamine tan were the airways of animals exposed only to air (AU)