Timing

SO₂ (ppm)

NO₂ (ppm)

CO (ppm)

O₃

(ppm)

PM_2.5 (μg/m³)

PM₁₀ (μg/m³)

Before Lockdown (BL)

<0.1 - 1.2

<0.1 - 0.1

8 - 28

<0.1

20 - 140

15 - 135

During Lockdown (DL)

<0.1 - 0.2

<0.1

1 - 12

<0.1

5 - 60

10 - 50

After Lockdown (AL)

0.1 - 0.6

<0.1 - 0.1

4 - 16

<0.1

10 - 110

10 - 90