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Pollutant Concentrations

Readings on 15 Mar 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 6(4) 22(22) 35(-) 35(15) 0.4(4) 11(44)
South 21(13) 24(24) 18(-) 29(12) 0.4(4) 9(38)
East 6(4) 18(18) 5(-) 48(20) 0.4(4) 10(42)
West 7(5) 28(28) 7(-) 60(26) 0.4(4) 15(54)
Central 18(11) 23(23) 24(-) 41(17) 0.3(3) 11(45)

1-hr PM2.5 (µg/m3)b Readings on 14 Mar 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 7 11 12 7 5 8 12 12 15 5 7 6
South 5 5 6 4 12 10 7 7 11 14 13 6
East 7 5 7 11 16 14 13 14 12 8 14 12
West 12 14 19 9 9 8 8 9 7 17 14 13
Central 15 10 7 8 11 6 9 15 12 5 6 15
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 9 17 15 20 24 14 9 11 4 8 7 8
South 9 11 18 16 13 16 4 7 6 1 3 7
East 12 15 11 8 8 15 13 5 4 7 5 7
West 22 13 19 26 33 27 28 20 7 14 4 6
Central 7 11 9 16 8 11 14 11 17 16 9 8

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 14 Mar 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 40 38 40 38 40 39 41 43 46 46 45 44
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 46 49 52 54 56 57 55 53 45 38 32 32



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.