Droplet distribution and airborne bacteria in an experimental shower unit. (1st March 2018)

• Record Type: Journal Article
• Authors: Estrada-Perez, C.E.; Kinney, K.A.; Maestre, J.P.; Hassan, Y.A.; King, M.D.
• Is Part Of: Water research. Volume 130(2018)
• Page Start: 47
• Page End: 57
• Publication Date: 2018-03-01
• Subjects: Shower -- Particle tracking velocimetry (PTV) -- Wetted wall cyclone (WWC) -- Bacterial aerosols -- Microbiome; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2017.11.039
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Although human exposure to water aerosols is common in residential showers, the droplet distribution patterns generated in showers are not well understood nor is the bacteria released during shower operation. In this study, a two-phase flow Particle Tracking Velocimetry (PTV) algorithm was successfully used to characterize the spatial spray pattern and velocity field in two experimental showers (one low-flow and one high-flow). In addition, the airborne bacteria present in the shower over nearly 5 months of controlled operation was determined for both showers. The results indicate that the droplet velocity out of the low-flow showerhead (which had fewer orifices) was significantly higher than that out of the high-flow showerhead resulting in a higher aerosol number concentration in the low-flow shower and more consistent wetting of the shower wall. Both showerheads generated droplets in the respirable range and genera of potential health concern were observed in the shower aerosols measured both prior to and following shower operation. The study provides one of the first visualizations of droplet spray patterns in residential showers and provides insight into the airborne bacteria present in showers. Graphical abstract: Highlights: Particle Tracking Velocimetry reveals complex residential shower spray patterns. Droplet velocity for low-flow showerhead higher as a function of number of orifices. Showers generate respirable aerosols and contain bacteria of potential concern. Both increases and decreases in bacteria aerosol concentrations observed.