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Pollutant Concentrations

Readings on 16 May 2015

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) 37(37) 97(-) 5(2) 0.7(7) 24(64)
South 19(12) 27(27) 21(-) 10(4) 0.5(5) 19(59)
East 15(10) 23(23) 28(-) 20(8) 0.8(8) 17(57)
West 33(21) 31(31) 39(-) 14(6) 0.3(3) 19(58)
Central 11(7) 29(29) 30(-) 7(3) 0.5(5) 18(57)

1-hr PM2.5 (µg/m3)b Readings on 15 May 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 33 32 29 26 31 21 21 18 20 27 36 23
South 22 26 33 16 26 20 14 16 18 16 22 17
East 17 16 21 24 22 26 28 22 23 24 23 32
West 5 15 13 13 13 15 7 22 18 26 23 14
Central 13 20 20 20 26 24 25 17 22 17 23 34
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 12 11 9 25 31 23 32 24 15 27 25 16
South 5 15 30 36 26 11 24 27 17 6 3 7
East 6 8 11 15 15 15 15 17 16 10 7 5
West 7 24 22 24 31 32 29 29 23 17 14 11
Central 11 12 17 18 21 16 15 18 16 9 5 4

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 May 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 55 58 61 62 62 62 61 60 59 60 63 64
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 59 55 52 58 62 63 63 62 61 58 53 46



The real-time data is automatically published as soon as it is generated by our air monitoring stations. The data is subject to verification and correction subsequently if necessary.