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Pollutant Concentrations

Readings on 22 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) 34(34) 42(-) 13(5) 0.3(3) 20(60)
South 10(6) 26(26) 13(-) 15(6) 0.4(4) 15(54)
East 10(7) 21(21) 25(-) 24(10) 0.3(3) 15(54)
West 24(15) 38(38) 33(-) 16(7) 0.3(3) 23(63)
Central 8(5) 29(29) 29(-) 19(8) 0.3(3) 16(56)

1-hr PM2.5 (µg/m3)b Readings on 21 May 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 18 28 31 19 20 27 30 25 50 39 14 17
South 14 16 18 22 23 20 14 16 16 26 10 16
East 14 13 30 33 25 20 16 8 7 9 14 10
West 28 30 25 18 24 28 23 28 37 23 22 21
Central 19 21 19 21 23 22 23 29 26 15 12 10
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 12 17 12 10 15 12 14 14 11 16 11 14
South 8 12 21 10 13 15 7 12 12 19 13 12
East 16 13 11 8 25 12 11 13 9 10 13 16
West 25 16 18 30 24 34 19 20 9 12 21 10
Central 13 16 11 10 11 17 11 12 12 12 11 15

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 21 May 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 54 57 62 63 64 63 63 62 63 64 61 57
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 54 54 54 54 55 56 56 54 51 52 52 53



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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