The Journal of Hospital Infection

The Journal of Hospital Infection

Mitigation of microbial contamination from waste water and aerosolization by sink design

Journal of Hospital Infections

Title: Mitigation of microbial contamination from waste water and aerosolization by sink design

K.Cole, J.E. Talmdge

Published online: May 28, 2019

(Click to view Journal Abstract)


Healthcare-associated infections (HAIs) are a significant cause of increased medical costs, morbidity, mortality, and have been partly associated with sinks, their waste water outlets and associated pipework.


To determine whether an engineered sink could limit microbial aerosol contaminants in the air and sink basin. Methods Multiple comparisons were undertaken between an experimental sink, designed to limit
aerosolization and p-trap contamination to a control hospital sink, both connected to a common drain system. The experimental sink was equipped with ultraviolet light (UV), an aerosol containment hood, ozonated water generator and a flush system to limit bacterial growth/aerosolization and limit microbial growth in the p-trap. Nutrient material was added daily to simulate typical material discarded into a hospital sink. Surface collection
swabs, settle plates and p-trap contamination levels were assessed for bacteria and fungi.


The experimental sink had significantly decreased levels of bacterial and fungal p-trap contamination (99.9% for Tryptic Soy (TSA) and Sabouraud agar (SAB) plates) relative to the initial levels. Aerosol-induced contaminant from the p-traps was significantly lower for the experimental vs the control sink for TSA (76%) and SAB (86%) agar settle plates.


Limiting microbial contamination is critical for the control of nosocomial infections of in-room sinks, which provide a major source of contamination. Our experimental sink studies document that regular ozonated water rinsing of the sink surface, decontamination of p-trap water, and UV decontamination of surfaces limits microbial aerosolization and surface contamination, with potential to decrease patient exposure and reduce hospital acquired infections.

© 2019 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.