WHO Clean Air Guidelines

Safe Air Pollutant Levels

Annual mean < 5 µg/m³

Annual mean < 15 µg/m³

8-hour mean < 100 µg/m³

Annual mean < 10 µg/m³

24-hour mean < 40 µg/m³

8-hour mean < 10,000 µg/m³

How You Can Protect Yourself

Check your local Air Quality Index (AQI)

Monitor your local Air Quality Index (AQI) using reliable apps or websites to stay informed about daily pollution levels.

Wear masks on high-pollution days

Use certified masks to reduce exposure to harmful airborne particles.

Plant trees

Trees help improve air quality and reduce CO₂ in the atmosphere.

Use public transport

Reducing the use of private cars lowers pollution and promotes cleaner air for all.

Basic Protective Measures

Limit outdoor exercise and heavy exertion when AQI is “Unhealthy for Sensitive Groups” or worse.
Reschedule outdoor events to times with lower AQI (often morning or after rain).
Follow official “stay indoors” or “shelter” warnings from local authorities.

Keep outdoor pollution out: close windows/doors during high pollution (wildfire smoke, dust storms).
Use mechanical filtration: HEPA air cleaners are most effective; if unavailable, a box fan + MERV-rated filter works as a DIY alternative.
Avoid indoor pollution sources: stop burning candles, wood, incense; avoid frying foods at high heat; no indoor smoking.

N95 / FFP2 / KN95 respirators reduce inhaled particles if fitted properly. Recommended during high-pollution events or for vulnerable people who must go outside.
Surgical masks and cloth masks are less effective against fine PM2.5.

Special Guidance for Vulnerable People

Children, older adults, pregnant people, and those with heart/lung disease or diabetes should avoid outdoor exertion at AQI > 100.
Keep medications handy and follow your clinician’s emergency plan.
Consider temporary relocation to areas of lower pollution if prolonged high pollution is expected.

WHO Guidelines for Clean Air