Which organism is given as an example of a building-related illness (BRI)?

• A. Streptococcus
• B. Legionella
• C. Pseudomonas
• D. Mold spores

Answer: (B)

The main idea being tested is recognizing a classic organism linked to a building-related illness, which arises when people inhale contaminants from indoor building systems. Legionella pneumophila is the emblematic example because it grows in damp water systems inside buildings—like cooling towers, hot water tanks, and showers—and becomes a health risk when aerosolized water droplets are inhaled. This exposure can cause Legionnaires’ disease, a severe pneumonia, or Pontiac fever, a milder illness. The disease is tied to a specific indoor source, making it a textbook example of a building-related illness.

Streptococcus is primarily spread person-to-person through respiratory droplets and isn’t tied to building systems. Pseudomonas can inhabit water systems and affect susceptible individuals, but it isn’t the classic demonstration of a BRI. Mold spores can provoke allergic or irritant responses in buildings and are a major indoor air quality concern, but the strongest, most cited example of a BRI disease from a building source remains Legionella.