Risk Exposure to during Showering: The Difference between a Classical and a Water Saving Shower System.

The increase in legionellosis incidence in the general population in recent years calls for a better characterization of the sources of infection, such as showering. Water-efficient shower systems that use water-atomizing technology have been shown to emit slightly more inhalable particles in the range of bacterial sizes than the traditional systems; however, the actual rate of bacterial emission remains poorly documented. The aim of this study was to assess the aerosolisation rate of the opportunistic water pathogen during showering with one shower system representative of each technology. To achieve this objective, we performed controlled experiments inside a glove box and determined the emitted dose and viability of airborne . The bioaerosols were sampled with a Coriolis Delta air sampler and the total number of viable (cultivable and noncultivable) was determined by flow cytometry and culture. We found that the rate of viable and cultivable aerosolized from the water jet was similar between the two showerheads: the viable fraction represents 0.02% of the overall bacteria present in water, while the cultivable fraction corresponds to only 0.0005%. The two showerhead models emitted a similar ratio of airborne viable and cultivable per volume of water used. Therefore, the risk of exposure to is not expected to increase significantly with the new generation of water-efficient showerheads.