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Pollutant Concentrations

Air quality readings will be available hourly from 1am to 12am.

Readings on 26 Oct 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 3(2) 45(45) 33(-) 69(29) 0.5(5) 28(70)
South 9(6) 37(37) 20(-) 44(19) 0.4(4) 26(67)
East 13(8) 36(36) 13(-) 54(23) 0.4(4) 27(68)
West 29(18) 50(50) 39(-) 50(21) 0.4(4) 36(78)
Central 15(10) 33(33) 27(-) 54(23) 0.4(4) 23(64)

1-hr PM2.5 (µg/m3)b Readings on 25 Oct 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 35 28 22 26 24 26 32 49 65 42 33 32
South 18 24 26 24 19 21 21 22 19 41 49 51
East 27 23 24 22 30 25 28 23 26 27 32 68
West 26 30 39 41 44 38 42 47 44 38 41 45
Central 26 20 18 19 24 19 15 34 34 21 31 25
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 43 36 26 7 14 20 27 22 21 21 17 17
South 44 37 35 27 30 33 23 8 8 11 20 13
East 23 24 18 15 18 31 37 30 25 27 25 21
West 41 38 50 51 36 24 29 30 24 19 20 22
Central 28 24 24 24 23 28 32 22 14 18 15 20

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 25 Oct 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 68 67 66 66 68 68 68 71 75 77 78 81
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 82 80 74 70 67 66 68 67 64 60 59 59

Hourly updates of 3-hr PSI readings are provided from 1am to 12am. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.

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