This is a multi-part post that will be expanded on with various health hazard examples on our blog. We recently reported on Ethylene oxide, Formaldehyde, and Glutaraldehyde in hospitals.  We continue this discussion with a segment on Legionella.

According to the Center for Disease Control (CDC), Legionellosis is a respiratory disease caused by the Legionella bacteria. In some cases the bacteria causes a serious type of pneumonia called Legionnaires’ disease. The bacteria can also cause a less serious infection called Pontiac Fever that has symptoms similar to a mild case of the flu. It is estimated that 6,000 – 18,000 cases of Legionellosis occur each year.

A short list of the physiology of the Legionella bacteria:

  • It likes water
  • It lives naturally in warm rivers and lakes
  • It likes temps ~77-108 F
  • It can live between 68-128 F

In industrial and commercial settings, Legionella will potentially grow if water is not properly maintained – which is a major issue since many water supply systems are not as closely regulated as other potential environmental hazards such as underground/aboveground storage tanks or chemical storage areas.

Related Blog:
Mercury and Waste Anesthetic Gases

Legionella is commonly found in the following settings:

  • Domestic water systems – cooling towers (air-conditioning units for large buildings)
  • Hot water tanks and heaters
  • Steam systems
  • Recreational water including hot tubs
  • Decorative fountains and water features
  • Showers and faucets

These man-made water sources become a health problem when small droplets of water that contain the bacteria get into the air and people breathe them in.  Legionellosis has recently been reported in the media, including two examples:

  • Amusement park outbreak – 15 cases, two dead
  • Portuguese hospital – 32 cases, four dead

The press will highlight that this disease can be fatal and that an outbreak could lead to business shutdowns. The public stigma relating to the detection of Legionella is extensive.

Industrial Hygiene is the science and art engaged in the anticipation, recognition, evaluation, and control of these and other workplace health hazards.  ATC Group Services has 20 Certified Industrial Hygienists (CIHs) located across our 100-office network.  Many of these CIHs have first-hand experience with Legionella contamination and abatement in healthcare and public water supply scenarios.  ATC represents numerous types of industrial and commercial facilities and has managed Legionella investigations for:

  • Healthcare facilities
  • Long-term care facilities
  • Hotels and resorts
  • Industrial facilities
  • Building owners and managers
  • Insurance companies


This blog only scratches the surface of Legionella.  We have shared a Legionella quiz for your review and use.  Please click here to download it, or contact us if we can be of assistance.   

Topics: Health & Safety