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Pollutant Concentrations

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

Readings on 16 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 14(9) 53(52) 38(-) 48(20) 0.6(6) 29(70)
South 9(6) 45(45) 21(-) 50(21) 0.4(4) 34(76)
East 11(7) 37(37) 18(-) 62(26) 0.3(3) 30(71)
West 7(4) 56(54) 65(-) 33(14) 0.7(7) 39(82)
Central 22(14) 45(45) 39(-) 58(25) 0.5(5) 31(72)

1-hr PM2.5 (µg/m3)b Readings on 15 Oct 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 55 42 49 60 49 30 23 24 32 28 17 15
South 25 28 46 42 44 26 25 32 46 36 39 47
East 23 28 35 37 39 43 42 33 39 32 24 28
West 33 37 33 29 36 30 37 38 26 28 40 39
Central 20 42 41 39 37 38 28 37 44 25 18 36
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 24 21 23 24 19 17 17 26 25 20 22 34
South 35 52 67 43 42 28 19 21 27 20 12 19
East 32 36 29 25 29 28 31 27 22 15 19 16
West 46 42 53 69 60 31 38 40 34 35 46 44
Central 24 32 44 47 32 32 33 24 20 12 18 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 15 Oct 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 69 73 78 82 84 81 77 74 75 75 73 71
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 72 76 80 83 83 77 72 68 68 65 64 64

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.