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Pollutant Concentrations

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

Readings on 21 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 8(5) 66(58) 43(-) 60(26) 0.6(6) 38(80)
South 11(7) 49(49) 38(-) 41(17) 0.5(5) 36(78)
East 18(11) 46(46) 23(-) 54(23) 0.6(6) 37(80)
West 23(14) 68(59) 42(-) 40(17) 0.5(5) 49(93)
Central 25(16) 45(45) 56(-) 50(21) 0.5(5) 34(75)

1-hr PM2.5 (µg/m3)b Readings on 20 Oct 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 16 36 45 50 64 63 67 69 51 37 40 39
South 20 27 25 26 33 39 54 72 73 72 71 53
East 28 29 25 28 30 41 73 72 84 65 53 50
West 25 30 52 72 68 65 56 79 73 61 60 63
Central 23 23 22 34 40 40 55 62 67 56 46 31
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 44 41 40 22 18 36 41 22 18 21 11 16
South 46 39 40 30 36 15 16 13 7 16 20 19
East 35 34 27 23 26 27 32 23 22 24 25 23
West 60 46 50 38 37 39 33 32 30 27 33 47
Central 28 32 29 31 27 25 29 19 19 19 20 27

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 20 Oct 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 65 65 70 77 84 90 97 106 113 112 106 97
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 92 86 82 77 73 70 70 67 64 61 61 63

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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