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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 13 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) 17(17) 37(-) 24(10) 0.3(3) 8(35)
South 5(3) 19(19) 5(-) 20(9) 0.5(5) 10(40)
East 6(4) 15(15) 22(-) 32(13) 0.2(2) 9(39)
West 3(2) 22(22) 56(-) 17(7) 0.4(4) 11(44)
Central 13(8) 19(19) 61(-) 28(12) 0.3(3) 9(37)

1-hr PM2.5 (µg/m3)b Readings on 13 Dec 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 4 14 8 10 7 5 7 9 6 5 16 13
South 4 7 5 5 8 6 12 20 16 15 16 12
East 11 19 12 11 10 8 9 6 7 7 11 10
West 19 17 9 9 8 5 10 13 14 23 17 15
Central 9 7 6 9 6 5 6 9 22 9 14 7
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 14 8 5 4 9 11 8 3 4 8 8 -
South 13 11 15 8 11 10 1 1 4 15 7 -
East 9 6 8 10 9 11 8 4 7 7 12 -
West 10 8 9 8 5 7 2 3 9 13 16 -
Central 13 5 3 12 9 17 5 3 5 11 16 -

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 13 Dec 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 37 42 42 42 35 32 31 36 46 51 52 52
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 52 42 38 34 35 39 34 26 19 27 40 -

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.