oEPA

United States
Environmental Protection
Agency

Point of use filter
Legionella

Inventors: Hodon Ryu

US Patent 11 104.591

TRL 3

Context

The bacterium Legionella pneumophila causes Legionnaires' disease and Pontiac fever. Most people become
infected when they inhale microscopic water droplets containing Legionella bacteria. Incidence of Legionella
infections has been increasing since 2000 and a recent study estimated that the true number of Legionnaires'
disease cases may be 1.8-2.7 times higher than what is reported.1 With a total estimated direct healthcare
cost of $402M, annually, it is increasingly important that point of use water systems disable Legionella
bacteria.2

Summary

EPA Researchers Ryu and Woo have invented a point of use filter to disable Legionella. Currently optimized
for use in showerheads, the filter disables the bacteria with low-power light emitting diodes (LEDs) operating at
many wavelengths in many channels and is boosted by a photo reactant metallic layer. Optimized for
consumer use, the filter assembly will require less frequent maintenance than barrier-based filtration methods
and is compatible with both standard and low flow shower head systems. The filter assembly is species
agnostic and may be used to disable opportunistic pathogenic bacteria beyond Legionella.

Potential Applications

•	Consumer DIY

•	Groundwater Well Systems

•	Clean Water Solutions for Developing Countries

•	Healthcare Facilities

Contact

Meghan Sheehan. JD. CLP
Federal Technology Transfer Act (FTTA) Specialist
wvwv.epa.gov/ftta

1 Collier SA. Deng L. Adam EA, et al. Estimate of b urden and direct healthcare cost of infectious waterborne disease in the U nited
States. Emerg Infect Dis. 2021:27( 1): 140-9.

5 Ibid.

U.S. Environmental Protection Agency

Office of Research and Development

for disabling

j Hvounqmin Woo


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