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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 15 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 6(4) 18(18) 33(-) 19(8) 0.2(2) 9(40)
South 4(2) 18(18) 5(-) 15(6) 0.4(4) 9(36)
East 7(4) 18(18) 23(-) 20(9) 0.3(3) 11(47)
West 4(2) 17(17) 8(-) 19(8) 0.4(4) 8(34)
Central 12(7) 15(15) 21(-) 24(10) 0.5(5) 7(29)

1-hr PM2.5 (µg/m3)b Readings on 15 Dec 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 9 5 8 13 8 10 7 3 8 12 21 18
South 6 6 7 3 6 5 8 8 6 7 22 16
East 11 13 23 14 15 15 15 15 12 18 18 12
West 12 10 12 5 7 9 6 4 5 4 10 16
Central 4 9 5 5 5 9 10 8 6 4 8 10
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 15 9 10 9 10 5 8 7 8 4 11 -
South 21 17 8 17 6 3 2 7 17 5 3 -
East 7 10 7 9 5 3 6 7 7 8 9 -
West 10 11 6 9 8 6 8 8 6 12 5 -
Central 10 8 7 11 7 4 5 5 8 9 4 -

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 15 Dec 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 33 34 39 38 37 35 37 36 34 34 45 52
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 53 52 43 41 35 31 24 23 30 33 33 -

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.