WHO Global Air Quality Guidelines: Understanding Health-Based Pollutant Levels
USEFUL SOURCES · OFFICIAL TECHNICAL RESOURCE · OCTOBER 2026
WHO’s Global Air Quality Guidelines provide health-based reference levels for major air pollutants and help readers put numerical measurements into context.
What Is This Resource?
The 2021 guidelines address particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. They evaluate evidence on health effects and provide guideline levels for particular averaging periods. This is a framework for public health interpretation rather than a product shopping catalog.
What You Can Find There
- Long- and short-term guideline levels for major outdoor air pollutants.
- Background on evidence linking exposure with health outcomes.
- Explanations of pollutant-specific averaging periods and interim targets.
- Guidance that can inform public health discussion and air quality policy.
How to Use It in Practice
When comparing a PM2.5 measurement with a WHO recommendation, confirm the instrument’s unit and averaging interval. A 24-hour value should not be compared directly with an annual guideline without explaining the difference. Consider measurement quality and exposure context rather than treating one short reading as a complete assessment.
Why It Matters for AirAlign
The guidelines help frame Basics articles on PM2.5, PM10 and gaseous pollutants and support careful interpretation of PM sensor data in Home and Commercial Air Quality content.
These health-based guidelines are not the same as legally enforceable national air quality standards, and they do not define a general CO₂ indoor ventilation threshold. Building-level decisions also require local standards and appropriate measurement.
Related Reading
Pair WHO guidance with local ambient air regulations and EPA or other government technical monitoring documents.
Official Reference
World Health Organization (WHO) — Official source →
AirAlign independent resource overview. Last researched 13 October 2026. Source availability and content can change; original provider materials remain authoritative.
