Legionella Pneumophila is Inactivated by UV-C Light

Legionella is Inactivated by UV-C Light


What is Legionella Pneumophila?

Legionella pneumophila is a bacterium that can be found in potable water sources such as fountains, showers, and taps—emerging from the distribution systems of large buildings such as hotels and hospitals. Potential non-potable sources include mist machines, humidifiers, whirlpool spas, showerheads, sink faucets, cooling towers, and hot springs. In particular, this bacterium is found in warm water.

Legionella is contracted through one of these ways:

  • Inhalation (primary way): Bacteria-contaminated droplets are breathed in, reach the lungs, and multiply there.
  • Aspiration (less common way): If drinking Legionella-contaminated water from a potable water source, liquid can accidentally enter your lungs if you choke or cough.

This bacterium can cause Legionnaires’ disease, a severe and often lethal form of pneumonia. Less often, it presents itself as a flu-like illness called Pontiac fever. Each year, an estimated 10,000 to 18,000 people in the United States are infected with the Legionella bacteria.


Where is it Found?


Shower sprayer with streams of water
Warm Water

What Does it Infect?


Man with lungs and upper respiratory tract showing
Lungs

How Does it Spread?


Breathing in another's respiratory droplets
Inhaling Droplets

How Does it Spread?


Breathing in another's respiratory droplets
Inhaling Droplets

Prevent the Spread of Legionella

Since Legionella is contracted through inhalation of bacteria-contaminated droplets from various water sources (potable and non-potable), preventing the spread of Legionnaires’ Disease requires developing an effective water management program.

According to the CDC, the principles of effective water managementopen_in_new include:

  • Ensuring adequate disinfection
  • Maintaining devices to prevent sediment, scale, corrosion, and biofilm (The presence of these provides a habitat and nutrients for Legionella.)
  • Maintaining water temperatures to limit Legionella growth
  • Preventing water stagnation

Once the water management program is established, regularly monitor key areas for potentially hazardous conditions. An effective program will be tailored to your facility with predetermined responses for when control measures aren’t met.

Get More Protection with UV Disinfection

Germicidal ultraviolet (UV-C) can provide the adequate water disinfection that is essential in water management programs — inactivating L. pneumophila in facility-wide water systems, hot tubs and those used for hydrotherapy, and public bathrooms containing showers.

Cooling towers convert water to air for central air conditioning. Large facilities using them (hospitals, hotels, and apartment buildings) can also benefit from UV-C air disinfection within their distribution systems to guard against the possibility of Legionella infection. Shop our products at AtlanticUltraviolet.comopen_in_new.

Learn about these applications:

View all UV-C Application Pages.

Our germicidal lamps produce ultraviolet wavelengths at 254 nanometers, the region of maximum germicidal effectiveness. Read our FAQ blog post to learn more. See dosage data below.

UV Applications for air and water disinfection of Legionella

Legionella Classification & UV-C Dose for Inactivation

Organism:Alternate Name:Type:Disease:UV Dose*:
Legionella pneumophilaL. pneumophilaBacteriaLegionnaires’ Disease, Pontiac Fever12.30 mJ/cm2
Legionella longbeachaeL. longbeachaeBacteriaLegionnaires’ Disease3.0 mJ/cm2

* Nominal Ultraviolet dosage necessary to inactivate better than 99% of microorganisms.

Legionella Symptoms

According to the CDC, symptoms usually appear from 2 to 10 days after exposure to these bacteria and may include:

  • high fever
  • chills
  • cough
  • chest pain
  • shortness of breath
  • muscle aches
  • headaches
  • diarrhea

Some individuals may suffer from long-term health effects such as persistence of fatigue, neurologic symptoms, and neuromuscular symptoms.

Sources on Legionella

The above information can be found on the following pages.

Dosage Source

Sensitivity of Bacteria, Protozoa, Viruses, and Other Microorganisms to Ultraviolet Radiation. Journal of Research of the National Institute of Standards and Technology, Volume 126, Article No. 126021. August 20, 2021.

Learn More, Shop & Contact Our Specialists

Since 1963, we’ve been engineering and manufacturing germicidal ultraviolet equipment to neutralize harmful microorganisms in water, in air, and on surfaces. Visit these helpful pages:

Shop at AtlanticUltraviolet.com

Contact Us

Atlantic Ultraviolet Corporation: Manufacturers, Engineers, Sales & Service, Since 1963

CM-000390