Abstract
Dust storms are said to exacerbate asthma in desert areas. We explored the role of dust component of dust storm in exacerbation of asthma by using equivalent amount of dust administered through an aerosol. Samples of sandy soil were collected from Bikaner, Jaipur and Ganganagar districts. Clay soil was procured from Ganganagar. These are dust storm prone areas of the state of Rajasthan in India. Dust aerosol was created in a specially designed re-suspension chamber to simulate mild to moderate dust storm. Concentration and size of dust particles (0.1 to 10μm) in the chamber was monitored with help of an aerosol spectrometer. Twenty patients with mild asthma having FEV1 more than 70% of predicted, were recruited in the study after obtaining an informed consent. These subjects were challenged with four samples of dust and placebo. The challenge aerosols were administered randomly in single blind cross over design on 5 study days at an interval of at least two weeks. Subjects took three tidal breaths of dust aerosol from the chamber. FEV1 was measured for next 60 minutes. Dust samples were also analysed for particle size and adhesiveness. The maximal fall in FEV1 was observed 15 min after exposure with all dust samples. Mean fall in FEV1 for clay, Bikaner, Jaipur and Ganganagar sand dust aerosol samples were (0.69±.08), (0.52±.06), (0.39±.07), (0.32±.04) liters respectively. It was observed that dust sample having higher adhesiveness and higher fraction of small size particles caused maximal fall in FEV1 (p<0.05). It can be concluded that small size dust particles of dust storm with higher adhesive properties have potential of causing aggravation of asthma.
- © 2011 ERS
