Pollutant, units

Rural, n

Rural Median

Rural 90^th Percentile

Urban, n

Urban Median

Urban 90^th Percentile

PM_2.5, µg/m³

245

6.06

17.9

330

6.0

13.5

PM_c, µg/m³

245

32.9

86.9

330

31.4

69.0

PM₁₀, µg/m³

245

41.3

106

330

38.5

83.5

CO, ppm

269

0.75

1.31

356

0.77

1.78

HCHO, ppm

269

<0.01^*

0.05

357

<0.01^*

1.03

H₂S, ppm

269

<0.06^*

0.12

357

<0.06^*

0.10

NO₂, ppm

269

<0.01^*

0.01

357

<0.01^*

0.01

SO₂, ppm

268

<0.01^*

0.05

357

0.01

0.04