Kelcroft E&M Limited
unit A10 Kowloon Bay Hong Kong
+852 2335 9830
home > news > legionella home > No Holiday for Legionella

No Holiday For Legionella

John A. Herbert
John Herbert
Legionella Risk Assessemnt Legionnaires Disease Expert

Downtime is a perfect time for Legionella

Buildings harbour a particularly dangerous, potentially fatal bacteria named Legionella Pneumophila more commonly known as Legionella.

It can cause a potentialy fatal illness known as Legionnaires' Disease. It is contracted by inhaling water droplets (aerosols) that cause lung infection, not by person to person contact.

Legionellosis, is the term for all ilness caused by the Legionella family of bacteria, including at least two flu type illnesses, Pontiac Fever and Logihead Fever. And we also have a another derivation, Legionella Longbeachae, a soil based version of the bacteria, that has caused Legionnaires' Disease due to inhaling potting soil or compost dust. If that's is not enough trouble, there is also a branch of Legionella Like bacteria the Legionella-like amoebal pathogens (LLAPs).

Legionella Pneumophila has several sub-types, and L. Longbeachae has two sub-types. It must be said that research is on-going, and new discoveries are made everyday.

Legionella Pneumophila is one of the aqueous variety, it grows inside building water systems, and breeds in stagnant and warm water areas between 25-35 deg C, the temperatures often found in cooling towers, and domestic water systems.

In Hong Kong and South China in the summer the 'cold' water system is warm water system, due to heating exposed water tanks and piping in the tropical climate.

no holiday for legionella

L. Pneumophila is an aqueous bacteria, in nature it is commonly found in rivers and streams, and piped in to our buildings through the utility water system. Given the opportunity, it can breed inside everytype of manmade water system including cooling towers, domestic hot and cold water systems, air conditioners, irrigation systems, showers, ice machices, misting machines, spa baths, humidifiers, birthing pools, and other water systems.

Now, we are all preparing for the Chinese lunar new year holiday, when most organisations shutdown for an extended holiday period.

All across China and Hong Kong, cooling towers will fall silent for a week or two of rest. Water heaters, water tanks and piping will lie idle awaiting our return. In China most businesses are closed for 10 days or more.

That's a risk because Legionella will not be taking any holiday, given the right environment it will silently breed.

legionella no holiday for legionella

Take Precautions

Long holidays are high risk, whilst you are away the water systems, cooling towers, etc. are warm and motionless, a prefect breeding ground for Legionellae. Assess the risk, legionella can travel 6km from the source, some quick tips (without liability):
1. have a consultant assess the risk; 2. create planned shutdown / start up routinue, drain down water systems if possible; 3. before operating idle cooling towers and similar equipment, disinfect the piping and towers; 4. flush all water tanks and pipes before use; 5. avoid stagnate water in domestic hot and cold water piping; 6. dont inhale, avoid breathing aerosols during flushing, clean and disinfection procedures; 7. beware utility work, Legionella outbreaks are associated with the disturbance caused by water utility works;

About the Author

John A. Herbert is internationally recognised Legionella expert, and often cited in the media for his experience auditing buildings to reduce the risk of Leigonella Infection. He has worked in Asia for the last 20 years, he is REA, and BEAM Professional.

Related Reading


#legionella #holidays #outbreak #risk #assessment

kelcroft consultants hong kong