Legionella Can Originate From Locations Other Than Water Systems
Moisture in a commercial facility can provide the ideal environment for the growth of microbacteria and related microorganisms. Some of these bacteria can cause disease if they spread too far. Legionella is among the worst of the disease-causing organisms that have been known to grow in public places. It was identified in 1976 following an outbreak of a severe illness among attendees at an American Legion convention in Philadelphia. Legionnaires’ Disease, as the illness was called, was thought to have originated in a nearby water cooling tower.
Sources of Legionella
With the health of the public at stake, commercial facilities and buildings with features that contain significant amounts of moisture should be monitored to prevent the growth of legionella and associated microbacteria. Managers and owners should pay particular attention to areas where moisture levels stay consistently high and where water is often dispersed into the air. Aerosols and water droplets in the air can be easily inhaled, and if those droplets are contaminated with legionella, disease can quickly occur and spread. Some of the more common sources of airborne moisture with potential legionella contamination include:
- Swimming Pools: Both indoor and outdoor pools can be a source of microbacteria growth. As people enter and exit the water, moisture is dispersed into the air, creating an environment where a small quantity of water droplets will be inhaled. Chlorine and cleaning chemicals in pools usually will prevent the development of legionella and related bacteria. However, these treatments must be performed consistently and according to standards. If cleaning treatments are neglected, legionella bacteria could form.
- Spas: Spas and related retreats are a prime location for legionella growth since the water used for body treatments and relaxation is at a warm temperature in which bacteria can thrive. Human presence in spas provides significant amounts of material that bacteria can use as a food source, such as dead skin cells. The pipes and plumbing equipment that circulate water in a spa also can create a large system where bacteria can grow and be moved around. When the water features in a spa are moved around, the microscopic droplets in the air can be inhaled.
- Water fountains: Ornamental water fountains in malls can be visually striking and form a pleasant visual centerpiece, but the way they function makes them a prime location for legionella growth. Fountains that spray water upward can look spectacular, but the agitation of the water streams causes droplets to be dispersed into the air. As in other situations where aerosols are present, the droplets can be easily breathed in. Since the temperature of the water in the fountains is close to the temperature of the air around it, legionella bacteria easily can grow and thrive in it.
- Produce moisturizing: Grocery stores use misters and sprayers to keep produce moist and fresh. Not only does moist produce look more appealing, the water helps keep the food hydrated and usable for longer periods. The water sprayers in the produce section are designed to create aerosols and tiny water droplets. If legionella establishes itself in one of these systems, the bacteria are spread not only through airborne contamination but through the produce itself.
Prevention of Legionella
- Ensure that any sources of water and airborne moisture used in your facility have functional disinfection, filtration and treatment systems.
- Follow all local regulations on water treatment and usage.
- Follow authoritative recommendations for water testing and monitoring to ensure legionella does not have the chance to establish itself.
- Ensure chemical treatments or other preventive measures are applied consistently and at the frequency recommended by the manufacturer or other resource.
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