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Pollutant Concentrations

Readings on 20 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 5(3) 37(37) 49(-) 4(2) 0.4(4) 22(63)
South 16(10) 20(20) 15(-) 7(3) 0.4(4) 11(44)
East 12(7) 17(17) 24(-) 14(6) 0.6(6) 11(46)
West 24(15) 29(29) 43(-) 20(8) 0.3(3) 18(58)
Central 10(6) 20(20) 25(-) 8(4) 0.5(5) 12(50)

1-hr PM2.5 (µg/m3)b Readings on 19 May 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 21 28 23 36 50 46 38 21 19 17 24 23
South 11 2 6 5 4 12 13 7 15 26 12 10
East 8 9 9 10 5 6 9 7 16 16 18 17
West 18 17 10 13 17 25 34 46 31 33 20 13
Central 9 6 7 4 9 9 14 30 32 13 16 17
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 13 10 14 23 23 22 23 21 13 - 11 8
South 7 10 16 20 9 18 9 11 9 - 7 9
East 11 9 12 18 14 10 9 13 9 - 10 10
West 20 21 14 14 11 11 10 14 5 - 7 20
Central 12 16 14 14 10 8 7 12 6 - 6 7

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 19 May 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 51 51 51 51 53 56 59 61 62 62 60 58
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 55 53 52 54 54 54 52 52 48 - 35 39



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.

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