Legionaires Disease: Some Thoughts

Legionnaires strikes again. The tabloids have the industry on the run and the general public in a panic about the safety of air conditioning systems.

"Whose cooling tower was it?" will be the most asked question. The real answer to this is: it does not really matter.

No cooling tower manufacturer sells their product with Legionella as part of the purchase.

This latest outbreak will start the push by manufacturers of air cooled and adiabatic systems that only their product is “safe”.

The reality on this side is that because these systems are no where neare as efficient as water cooled systems we use more energy, create more pollutants and we could say ultimately create the potential for harming more people than the number of LD cases recorded each year.

It is about time the industry and in the so called “voice” of the industry, AIRAH start educating the general public rather than let the tabloids run riot. I think the last article I saw AIRAH produce on related topics was no more than a sales article for Muller Industries.

Let me explain something here. It is only when there are outbreaks from HVAC systems that legionella is noteworthy. About two years ago I finally thought that the Legionella “scare tactics” employed by the tabloids to sell their product had run it’s course.

On page 22, in a one column by perhaps 30 lines, there was an article about a case of two people having contracted LD. When I saw the headline I thought “about bloody time” someone had some common sense.

The reality was as I read the article that the people had contracted LD from potting mix.

Why was this LD case relegated to page 22? Simple. Potting mix does not sell papers.

Now let’s get back to the statement I made that cooling tower manufacturers do not sell their product with LD.

So where does Legionella come from? From many sources. You will find that the general consensus about Legionella is that it is a naturally occurring bacteria, found in the soil and ground water.

This has always fascinated me. Consider if you will, a cooling tower situated on the 40-something floor or higher. Where does the soil come from? Dust particles? Surely they would be bone dry. So that leaves water bourne contamination as a possibility. So the logical source of contamination in a lot of cases must be the local water supply.

Interestingly all responsibility for control of the disease has been shifted to the HVAC industry and to building owners. Who actually should be responsible for providing “safe” water?

I’ll leave the industry with those thoughts.