Effect of Asian dust on pulmonary function in adult asthma patients in western Japan: A panel study

抄録

Background: Asian dust (AD) has become a major health concern. The concentration of AD is typically expressed in particulate matter less than 10 μm (PM₁₀) and 2.5 μm (PM_2.5). However, PM₁₀ and PM_2.5 consist of various substances besides AD. Light detection and ranging (LIDAR) systems can selectively measure the quantity of AD particles to distinguish non-spherical airborne particles from spherical airborne particles. The objective of this study was to investigate the relationship between pulmonary function in adult asthma patients and AD using LIDAR data. Methods: Subjects were 231 adult asthma patients who had their morning peak expiratory flow (PEF) measured from March to May 2012. A linear mixed model was used to estimate the association of PEF with sand dust particles detected by LIDAR. Results: Increases in the interquartile range of AD particles (0.018 km^-1) led to changes in PEF of -0.42 L/ min (95% confidence interval [CI], -0.85 to 0.01). An increase of 11.8 μg/m³ in suspended particulate matter and 6.9 μg/m³ in PM_2.5 led to decreases of -0.17 L/min (-0.53 to 0.21) and 0.03 L/min (-0.35 to 0.42), respectively. A heavy AD day was defined as a day with a level of AD particles >0.032 km^-1, which was the average plus one standard deviation during the study period, and six heavy AD days were identified. Change in PEF after a heavy AD day was -0.97 L/min (-1.90 to -0.04). Conclusions: Heavy exposure to AD particles was significantly associated with decreased pulmonary function in adult asthma patients.