Assesses the impact of Legionella on indoor air quality and on the heating, ventilation and air conditioning industry. Reviews the disease, the causative agent and the mode of transmission. Examines the risk of infection and environmental control. Notes findings that good maintenance is effective in the control of legionellae. Nots the role of protozoa in selectively amplifying Legionella in water systems.

KEYWORDS: Health, hazards, cooling towers, bacteria, indoor, air quality, maintenance, legionnaires disease