Demystifying Air Quality Terms—What Do VOCs, PM2.5, and AQI Really Mean?

Demystifying Air Quality Terms—What Do VOCs, PM2.5, and AQI Really Mean?

Author: Dr. David Hernández, Air Quality Research Scientist

Air quality terminology can feel overwhelming. Here’s what the most important terms really mean, backed by research.

  • VOC (Volatile Organic Compounds): Gases released from paints, cleaners, and furnishings. Chronic exposure has been linked to headaches, nausea, and long-term liver/kidney effects (Agency for Toxic Substances & Disease Registry, 2021).

  • PM2.5: Fine particulate matter less than 2.5 microns. WHO states PM2.5 contributes to millions of premature deaths each year, largely from heart and lung disease (WHO, 2021).

  • AQI (Air Quality Index): Developed by the EPA to measure daily air pollution. A “moderate” AQI can still be harmful for sensitive groups.

  • Carbon Monoxide (CO): A colorless, odorless gas. CDC reports that over 400 Americans die annually from accidental CO poisoning.

  • Humidity Levels: High humidity fosters mold growth; low humidity irritates respiratory passages. Maintaining balance protects health.

Bottom Line:
Understanding these terms gives homeowners power to act. Regular testing ensures your family is breathing safe, clean air.