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Pollutant Concentrations

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

Readings on 28 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 6(4) 41(41) 56(-) 38(16) 0.7(7) 24(65)
South 18(11) 42(42) 78(-) 27(11) 0.6(6) 30(71)
East 23(15) 43(43) 55(-) 52(22) 0.6(6) 31(73)
West 12(7) 43(43) 83(-) 34(14) 0.7(7) 26(66)
Central 21(13) 40(40) 80(-) 16(7) 0.7(7) 27(68)

1-hr PM2.5 (µg/m3)b Readings on 28 Oct 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 27 28 20 25 21 17 11 11 16 28 23 19
South 20 22 25 29 26 16 13 14 10 38 41 46
East 31 28 24 25 24 22 17 28 25 40 43 42
West 22 29 12 15 11 14 19 17 11 20 20 26
Central 18 23 32 23 17 18 17 12 20 14 16 22
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 23 15 34 21 26 29 42 38 20 32 40 -
South 38 40 21 25 50 39 38 26 43 38 36 -
East 33 45 23 8 30 35 45 27 34 52 44 -
West 30 28 23 29 36 34 39 36 41 39 44 -
Central 23 36 33 15 42 42 37 40 44 45 37 -

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 28 Oct 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 59 63 65 64 62 60 57 56 56 60 65 70
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 71 73 71 67 69 72 80 79 79 79 82 -

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.