 The purpose of this study is to develop a nasal challenge model that causes a mild degree of inflammation, without causing any pain or symptoms, but that allows us to measure a variety of proteins in nasal secretions which causes inflammation in the nose. The nasal challenge model involves spraying the nostrils in the form of a fine mist with 4 different doses 1, 10, 30 and 100μg per nostril of lipopolysaccharide LPS including a placebo. LPS is a type of protein which has been carefully purified from the outer cell wall of certain bacteria, is sterile and does not contain live bacteria, and will not cause infection. 