Air quality·coarse dust PM10 450
coarse dust PM10 450µg/m³
AQI 330
hazardous · very bad

coarse dust PM10 450 µg/m³ — AQI 330

coarse dust PM10 at 450 µg/m³ scores 330 on the US index, and the Korean grade calls it very bad.

Both systems agree here

Concentration
450 µg/m³
US index (AQI)
330
US category
hazardous
Korean grade
very bad
Concentration that makes 100
154 µg/m³

Same number, different verdict

A Korean forecast calls PM10 of 150 "bad", but the same value in the US index is 98 — still moderate. The other way round, PM2.5 of 40 has only just crossed into "bad" in Korea while the US index already reads 112, unhealthy for sensitive groups. Neither is wrong; they hold different rulers. Move country and the same air reads differently.

Nearby cells

Same pollutant, other concentrations

How to read this

  • On the left is the US index, on the right the Korean grade — the same concentration measured with two rulers.
  • Index values of 50, 100 and 150 are the boundaries; that is where the category name changes.
  • Forecast grades are usually daily averages, not the reading at this moment.
  • The cigarette figure is only for PM2.5 and assumes a full day of exposure.

Frequently asked questions

Q. How bad is coarse dust PM10 at 450 µg/m³?

330 on the US index, and very bad on the Korean scale.

Q. Do the two systems agree?

Yes, both read it the same way here.

Q. What concentration would make the index 100?

154 µg/m³. This page is at 450 µg/m³.

Q. What is this pollutant?

coarse dust PM10. The cigarette comparison is only applied to PM2.5.