Study to Explore the Effects of Two Hour Inhalation of Ultrafine Carbon Black Particles on Airway Inflammation in Asthmatics

The aim of the study is to test the hypothesis that the allergic airway inflammation in asthmatic patients will be enhanced after exposure to ultrafine particles (UFP). In order to test this in a controlled study, the researchers combine controlled exposure to carbon black model UFP with the well-established model of a segmental allergen challenge, which allows the researchers to safely induce circumscript allergic inflammation in the lung in mild asthmatics. The effect of the UFP on allergic inflammation will be controlled by an inhalation of clean air in a randomized, double-blind, crossover design.