Consultants Suggest How to Prevent Legionnaire's Disease

Two Ford Motor Co. workers who died last week had Legionnaire''s disease, bringing to five the number of cases confirmed among workers at an engine casting plant in Cleveland.

Symptoms of Legionnaires'' disease, first identified when an outbreak occurred during the 1976 American Legion convention in Philadelphia, include high fever, cough and shortness of breath.

The recent outbreak has increased the need to inform employers about the disease in an effort to minimize the chances of workers being exposed to the bacteria.

CEC Consultants Inc., Cleveland, Ohio, specializing in developing corporate-wide indoor air quality programs, said Legionella bacteria has always been around and is almost everywhere in water and soils.

The good news, according to John Puskar, P.E. and consultant at CEC, is that Legionella''s ability to thrive, multiply and disseminated can be controlled.

"Those who work with or near equipment that is traditionally high-risk equipment need to be especially aware of proper maintenance and controls to minimize the chance of contamination," said Puskar.

Equipment that has a special capability to breed, multiply or disseminate Legionella includes the following:

• Architectural Fountains and Waterfalls: (Malls, shopping centers, restaurants and even private residential office displays).
• Cooling Towers: (These come in many types and sizes but in general they are at or near wherever commercial air conditioning or refrigeration processes take place. This could mean hospitals, schools and or facilities even with large air compressors or cold storage facilities).
• Evaporative Coolers: (Athletes at football and or baseball games may be at risk because some industrial facilities have added evaporative cooling in lieu of air conditioning).
• Evaporative Air Coolers: (These are another cooling tower technology that are also associated with commercial air conditioning and heat rejection processes).
• Car Washes: (Car washes with recirculated water could be a source in summer periods, especially rinse sections).
• Showers: (Workers showering and/or cleaning/maintenance personnel who are stationed near or frequently in contact with showers that have domestic water systems loaded with Legionella can be at risk).
• Parts Washers: (Parts cleaning processes in industrial plants can make for risks. Especially those that have rinses and or water blow off sections associated with them).
• Paint Booths: (Many paint booths and painting processes use humidification systems to control and maintain optimal humidity).

Puskar noted that in every case this equipment faces common characteristics that make it capable of accelerating the breeding rate, making it into aerosol, or spreading the droplets.

"Remember, it''s very unlikely that one would ever get Legionella from drinking contaminated water or skin contact," said Puskar. "It''s primarily an issue of breathing in droplets."

What Can Be Done?

Puskar said that it is only through longer-term monitoring and enhanced maintenance practices that the Legionella threat will be completely minimized.

However, in the short term Puskar said employers can take steps to minimize the threat.

These include the following:

1. Personal Protective Equipment: Make sure employees servicing any cooling towers or at risk equipment wear proper personal protective equipment including at least dust masks or respirators to minimize the chance for the inhalation of droplets.

2. Medical Considerations: Consider prioritizing who works on which assignments. Remember, those that smoke and/or have some type of immune system compromise are especially at risk. Those under some type of medical care and even those just getting over a cold or flu should not be in a position to be exposed.

3. Start-up/Shut Down Procedures: Make sure that you have start-up/shut down procedures that parallel American Society of Heating Refrigeration and Air Conditioning Engineers guidelines. These procedures discuss topics such as proper draining, decontamination and maintenance procedures for minimizing risks.

Additionally, Puskar said that if you suspect a problem, emergency precautions should include immediate shut down of systems, testing and decontamination.

by Virginia Sutcliffe