Seasonal Variability of Air Pollutants and Their Relationships to Meteorological Parameters in an Urban Environment

Figure 4

Boxplots of (a) PM10, (b) PM2.5, (c) CO, (d) NO₂, (e) O₃, and (f) SO₂ concentrations at nighttime (18:00 hrs–06:00 hrs).

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(b)

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(e)

(f)

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(i)

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(l)