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Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

 

Readings on 20 Dec 2014

View reading for:

Region 24-hr Sulphur dioxide
(µg/m3) 		24-hr PM10
(µg/m3) 		1-hr Nitrogen dioxide
(µg/m3)a 		8-hr Ozone
(µg/m3) 		8-hr Carbon monoxide
(mg/m3) 		24-hr PM2.5
(µg/m3)
North 7(4) 17(17) 33(-) 10(4) 0.4(4) 8(35)
South 6(4) 15(15) 6(-) 19(8) 0.3(3) 8(33)
East 3(2) 15(15) 11(-) 19(8) 0.4(4) 10(42)
West 4(3) 14(14) 26(-) 16(7) 0.4(4) 7(27)
Central 7(5) 15(15) 39(-) 29(12) 0.4(4) 8(34)

1-hr PM2.5 (µg/m3)b Readings on 20 Dec 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 6 5 7 5 10 17 18 17 14 22 4 7
South 7 8 7 4 8 3 5 3 6 19 5 9
East 7 7 11 10 9 10 7 8 9 15 16 15
West 8 3 7 3 4 4 6 6 6 11 10 9
Central 6 11 4 14 13 11 7 6 5 6 8 7
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 5 5 5 6 15 6 5 4 4 7 6 -
South 10 10 9 15 17 9 5 3 3 7 4 -
East 5 7 4 11 21 4 6 11 17 11 6 -
West 7 11 2 8 9 8 2 4 8 6 9 -
Central 8 3 4 5 19 13 4 10 9 8 5 -

Note:
a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on 20 Dec 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 29 28 29 32 35 38 37 36 34 42 43 45
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 35 33 26 29 42 46 40 26 26 31 31 -

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.

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