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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 22 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) 16(16) 36(-) 8(3) 0.4(4) 8(32)
South 6(4) 16(16) 4(-) 13(5) 0.3(3) 9(36)
East 5(3) 15(15) 19(-) 11(5) 0.4(4) 9(38)
West 5(3) 15(15) 8(-) 15(6) 0.4(4) 6(27)
Central 7(4) 14(14) 37(-) 29(12) 0.3(3) 6(26)

1-hr PM2.5 (µg/m3)b Readings on 22 Dec 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 5 6 8 4 6 7 6 9 5 11 14 14
South 2 3 2 2 1 6 5 11 11 10 14 21
East 10 9 8 7 8 6 8 7 9 11 7 13
West 5 4 4 5 5 5 6 9 6 8 8 7
Central 4 3 4 4 4 6 8 9 8 5 8 10
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 13 10 8 8 8 7 6 4 3 6 8 -
South 21 23 17 20 14 10 3 2 1 1 4 -
East 7 13 12 22 13 9 8 3 5 3 5 -
West 4 12 7 18 9 8 4 4 6 3 4 -
Central 5 12 5 8 7 11 9 4 4 4 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 22 Dec 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 27 24 21 20 20 21 24 30 32 36 38 45
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 46 51 47 52 49 47 35 26 18 15 17 -

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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