On the Understanding of the transmission route tied to Reported Influenza/Influenza-Like Illness Activity

Some studies suggest atmospheric particulate matter with diameters 2.5 micron and smaller (PM2.5) may possibly play a role in the transmission of influenza and influenza-like illness (ILI) symptoms.  Those studies were predominantly conducted under moderately to highly polluted outdoor atmospheres.  We conducted our study to extend the understanding to include a less polluted atmospheric environment.  A relationship between PM2.5 and ILI activity extended to include lightly to moderately polluted atmospheres could imply a comparatively more complicated transmission mechanism.  We obtained concurrent PM2.5 mass concentration data, meteorological data and reported Influenza and influenza-like illness (ILI) activity for the light to moderately polluted atmospheres over the Tucson, AZ region. We found no relation between PM2.5 mass concentration and ILI activity. There was an expected relation between ILI, activity, temperature, and relative humidity.  There was a possible relation between PM2.5 mass concentration anomalies and ILI activity. These results might be due to the small dataset size and to the technological limitations of the PM measurements. Further study is recommended since it would improve the understanding of ILI transmission and thereby improve ILI activity/outbreak forecasts and transmission model accuracies.