EFFECTS OF PHOTOCHEMICAL AIR-POLLUTION AND ALLERGEN EXPOSURE ON UPPERRESPIRATORY-TRACT INFLAMMATION IN ASTHMATICS

Asthma is an inflammatory disease of the airways, and exacerbations of this disease have been associated with high levels of air pollution. The objective of this study was to examine whether ambient air polluti on and/or allergen exposure induces inflammatory changes in the upper airways of asthmatics. Sixty patients with intermittent to severe pers istent asthma visited the Hospital's Out Patient Clinic every 2 wk for a period of 3 mo, and on each visit a nasal lavage was obtained. Asso ciations between nasal inflammatory parameters and seasonal allergens and/or air pollution exposures were analyzed using linear regression a nalysis. The study ran from July 3 to October 6, 1995, during which pe riod ozone (8-h mean: 80 mu g/m(3)) and PM10 (24-h mean: 40 mu g/m(3)) were the major air pollutants; the major aeroallergen was mugwort pol len (24-h mean: 27 pollen grains/m(3)). Effects on both cellular and s oluble markers in nasal lavage were demonstrated for both ozone and mu gwort pollen, but not for PM10. Ambient ozone exposure was associated with an increase in neutrophils (112% per 100 mu g/m(3) increase in 8- h average ozone concentration), eosinophils (176%), epithelial cells ( 55%), IL-8 (22%), and eosinophil cationic protein (ECP) (19%). Increas es in environmental mugwort pollen counts were associated with an incr ease in nasal eosinophils (107% per 100 pollen/m(3)) and ECP (23%), bu t not with neutrophils, epithelial cells, or IL-8. This study demonstr ated that both ambient ozone and allergen exposure are associated with inflammatory responses in the upper airways of subjects with asthma, although the type of inflammation is qualitatively different.