WordsPM2.5
ฝุ่น PM2.5 · fun PM song chut ha
Particles under 2.5 micrometres across — small enough to go past the nose and into the lungs.
What it is
Particles under 2.5 micrometres across — small enough to go past the nose and into the lungs.
The long version
It is measured in micrograms per cubic metre. The United States set its 24-hour standard at 35.4 µg/m³ and, in a 2024 revision, moved the annual standard to 9.0; the AQI figures on this site use that revision's breakpoints.
Inference — it is the number that matters here rather than visibility because the size that carries a particle deep into the lungs is also what makes it invisible on its own. A hazy day and a high-reading day are not the same list.
Runs with
- storyThe smoke — Four years of it, measured.
- hazardRiding in the smoke — What it does on a bike.
Named here by
- hazardRiding in the smoke — What is actually in the air.
- storyThe smoke — What the number measures.
Where each claim comes from
| Field | Tier | Source | Note |
|---|---|---|---|
| default | cited | Final Reconsideration of the National Ambient Air Quality Standards for Particulate Matter — US Environmental Protection Agency | |
| text.story | cited | Final Reconsideration of the National Ambient Air Quality Standards for Particulate Matter — US Environmental Protection Agency | |
| text_th | inference | written in Thai by this project, not machine-translated |
Sources
- Final Reconsideration of the National Ambient Air Quality Standards for Particulate Matter — US Environmental Protection Agency
- Open-Meteo Air Quality API (Copernicus CAMS) — Open-Meteo
- Southeast Asian haze — Wikipedia (en)
cited Cited — a named source, linked · harvested Harvested — fetched from an open dataset, with its licence · tradition Tradition — general knowledge of the tradition, hedged · inference Inference — this project's own reasoning from the above · field Field — someone stood there