In a cooling tower system, what specific biological risk is identified?

• A. Legionella bacteria in aerosols.
• B. Staphylococcus aureus contamination.
• C. Aspergillus mold only in HVAC ducts.
• D. Viral aerosols from processing equipment.

Answer: (A)

In a cooling tower system, the main biological risk is Legionella bacteria present in the aerosols that are emitted from the tower. When warm water in the tower becomes aerosolized to dissipate heat, tiny droplets containing Legionella can be inhaled by people nearby. If inhaled, the bacteria can cause Legionnaires’ disease, a serious flu-like pneumonia, or Pontiac fever, a milder illness. This is why water quality and disinfection in cooling towers are critical: maintaining proper disinfectant levels, controlling the water temperature and stagnation, and using drift eliminators and regular monitoring help prevent Legionella growth and spread.

Other organisms like Staphylococcus aureus, molds such as Aspergillus in HVAC ducts, or viral aerosols from equipment can be concerns in some settings, but the distinctive, well‑documented risk associated with cooling towers is the inadvertent dissemination of Legionella through the aerosols they generate.