Proposed modification to the inhalable aerosol convention applicable to realistic workplace wind speeds

Abstract

The current convention for sampling inhalable aerosols was based on several mannequin studies performed in wind tunnels at wind speeds between 0.5 and 4 m s -1. In reality, as we now know, the wind speed in most modern indoor working environments is generally at or below ∼0.2 m s -1. Inhalability studies performed in calm air aerosol chambers have shown that human aspiration efficiency at essentially zero wind speed is not consistent with the existing inhalable aerosol convention, calling into question the universal applicability of the current standard. More recently, experiments were carried out in a new hybrid wind tunnel-calm air chamber at more representative workplace wind speeds, between ∼0.1 and 0.5 m s -1, to fill in this knowledge gap. Comparing these new data to both the existing inhalable aerosol convention and a recently proposed alternative for low wind movement suggests that, while the existing inhalable aerosol convention remains appropriate for wind speeds above ∼0.2 m s -1, the modified version is more appropriate for the range below ∼0.2 m s -1. © 2011 The Author.