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Pollutant Concentrations

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

Readings on 22 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) 49(49) 46(-) 15(6) 0.8(8) 29(70)
South 11(7) 41(41) 53(-) 12(5) 0.8(8) 30(72)
East 12(8) 35(35) 35(-) 17(7) 0.8(8) 28(69)
West 9(5) 47(47) 35(-) 22(9) 0.8(8) 34(75)
Central 20(13) 37(37) 55(-) 22(9) 0.8(8) 26(67)

1-hr PM2.5 (µg/m3)b Readings on 21 Oct 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 19 23 28 33 42 52 51 43 38 32 43 37
South 24 18 13 15 19 26 35 47 52 61 59 31
East 21 20 18 18 18 22 32 30 43 42 40 38
West 55 57 50 46 45 37 34 40 38 38 40 37
Central 22 20 18 16 16 33 47 35 45 41 53 29
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 10 8 26 29 30 24 20 18 14 21 23 26
South 12 42 38 42 57 50 20 6 13 10 14 21
East 22 38 23 21 29 43 32 34 28 24 23 23
West 27 24 38 52 44 32 7 11 8 16 15 18
Central 3 26 31 27 42 26 23 15 17 14 15 19

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 21 Oct 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 66 68 68 67 67 70 76 80 83 84 87 84
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 74 66 65 72 77 79 73 65 57 56 57 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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