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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 21 Nov 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 2(1) 26(26) 47(-) 16(7) 0.4(4) 12(51)
South 7(5) 21(21) 52(-) 13(6) 0.5(5) 10(43)
East 3(2) 17(17) 22(-) 25(11) 0.3(3) 11(46)
West 4(2) 25(25) 52(-) 19(8) 0.6(6) 12(51)
Central 7(4) 18(18) 50(-) 32(13) 0.6(6) 11(44)

1-hr PM2.5 (µg/m3)b Readings on 21 Nov 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 9 18 11 11 6 5 4 5 9 6 10 8
South 14 7 4 5 5 3 7 2 7 11 12 28
East 19 24 11 13 11 8 9 10 8 9 14 14
West 7 11 9 11 5 3 13 13 9 10 10 18
Central 14 16 11 7 5 5 7 7 11 9 8 14
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 8 12 12 8 17 18 22 15 22 16 24 -
South 9 17 20 9 9 27 12 10 7 6 6 -
East 6 13 9 9 14 16 6 5 10 6 8 -
West 12 12 18 14 16 16 17 20 14 14 14 -
Central 10 21 14 9 8 27 11 7 2 5 8 -

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 21 Nov 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 52 53 51 47 35 28 26 28 34 35 40 50
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 51 53 52 52 51 54 55 54 49 44 45 -

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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