Which statement best identifies a comprehensive approach to controlling indoor air pollutants?

• A. Filtration only
• B. Ventilation by opening windows
• C. Dilution, Extraction, Source Control
• D. Ultraviolet disinfection without filtration

Answer: (C)

A robust indoor air quality strategy uses a combination of controls: reduce pollutant sources, dilute contaminants with ventilation, and remove pollutants at the source or in the air path. This multi-pronged approach protects against a wider range of pollutants, including particulates, gases, and bioaerosols.

Filtration alone only captures particles and doesn’t address gases or VOCs. Opening windows for ventilation is variable and depends on outdoor conditions, and it doesn’t curb emissions from sources inside or remove contaminants that have already formed. Ultraviolet disinfection without filtration targets microbes and doesn’t effectively reduce chemical pollutants or particulates, and it isn’t a substitute for filtration or extraction.

Therefore, combining source control, dilution through ventilation, and extraction (local removal at the source) provides the most comprehensive protection against indoor air pollutants.