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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 17 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) 37(-) 9(4) 0.5(5) 8(34)
South 3(2) 16(16) 11(-) 11(4) 0.8(8) 9(36)
East 8(5) 14(14) 34(-) 17(7) 0.4(4) 8(35)
West 4(3) 18(18) 46(-) 11(4) 0.4(4) 9(36)
Central 12(7) 14(14) 59(-) 16(7) 0.6(6) 7(29)

1-hr PM2.5 (µg/m3)b Readings on 17 Dec 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 7 8 4 5 6 11 9 8 13 9 7 5
South 8 4 3 4 5 4 3 12 10 10 11 4
East 11 11 3 6 5 7 6 8 4 8 18 12
West 9 6 10 11 10 8 6 6 9 13 9 4
Central 8 6 3 2 3 7 4 2 4 9 7 3
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 6 11 6 5 10 11 6 9 10 12 12 -
South 15 18 14 9 7 8 9 7 12 9 12 -
East 13 6 6 4 8 10 5 9 7 10 11 -
West 12 7 5 11 3 5 9 7 10 16 11 -
Central 13 12 5 6 20 8 3 6 9 12 10 -

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 17 Dec 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 36 33 28 23 22 26 26 28 29 35 39 36
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 39 40 42 35 33 34 34 31 33 41 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.