I work in a building which has Legionella in the water.

The building I work in has tested positive for Legionella bacteria. One individual fell sick last week. What are the risks to me if I keep showing up for work and inhaling the air conditioned air? Do you think I should leave?


Some hot spots were found in the building, two in air conditioning water cooler towers and one in a ladies bathroom sink, one floor beneath me. An outside Legionella risk management company came in to the building to conduct independent testing and found no Legionella bacteria present in the water supply. Then, the City Health Department conducted their tests; Legionella was present and potent. Is there still a risk if the building has been cleaned? Can you please give some direction. No one is telling us anything.

It is not well-known to the public that Legionella in large building water supplies is commonplace. The fact that Legionella was found in the workplace water systems of a sick person does not necessarily mean that this was the source of infection. If the Legionella organism was isolated from the patient, molecular typing can be done on both this organism and the Legionella recovered from the water systems. If they match, then there is a stronger probability that the workplace was the source.

The reason for not being overly concerned is that unless you have an immunosuppressive underlying illness or smoke cigarettes, you are at little, if any risk. Healthy individuals have many potential sources for exposure to Legionella in the community, as well as from home water systems. Although we understand your concern, no guidelines on workplaces or public buildings have been formulated because the risk is so low.