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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 Jan 2015

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) 25(25) 21(-) 27(11) 0.4(4) 11(47)
South 10(6) 25(25) 7(-) 29(12) 0.4(4) 10(42)
East 8(5) 27(27) 11(-) 47(20) 0.4(4) 15(55)
West 2(1) 28(28) 10(-) 48(20) 0.4(4) 10(43)
Central 4(2) 22(22) 21(-) 45(19) 0.3(3) 7(29)

1-hr PM2.5 (µg/m3)b Readings on 15 Jan 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 8 10 15 16 13 12 10 7 18 12 11 15
South 7 5 6 6 8 4 7 5 7 12 23 20
East 19 16 20 25 15 22 20 15 14 23 13 18
West 14 9 9 7 7 12 10 4 9 9 20 13
Central 5 7 2 6 2 4 3 3 8 7 11 9
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 11 11 10 9 10 8 8 10 7 17 13 -
South 14 21 14 12 20 8 12 9 7 7 7 -
East 17 9 8 11 10 12 12 16 8 16 14 -
West 20 11 12 8 7 12 8 10 9 10 11 -
Central 9 6 9 8 11 8 12 8 8 11 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 15 Jan 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 37 37 42 44 44 44 41 38 39 43 52 54
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 54 53 50 44 45 43 44 42 40 43 42 -

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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