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Pollutant Concentrations

Readings on 21 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 7(4) 53(52) 14(-) 98(42) 0.5(5) 35(77)
South 13(8) 51(51) 11(-) 74(31) 0.6(6) 36(78)
East 12(8) 43(43) 8(-) 82(35) 0.6(6) 35(77)
West 24(15) 58(55) 21(-) 106(45) 0.6(6) 42(85)
Central 9(5) 47(47) 42(-) 103(44) 0.5(5) 35(77)

1-hr PM2.5 (µg/m3)b Readings on 20 Mar 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 24 28 30 23 24 25 26 21 21 14 21 24
South 13 19 25 28 28 21 28 22 30 35 36 42
East 25 26 31 30 28 28 27 31 29 25 35 36
West 27 32 30 31 34 24 20 29 38 37 40 50
Central 19 24 22 24 20 22 25 20 26 26 32 32
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 30 43 58 67 56 61 67 49 35 34 29 28
South 38 47 68 70 55 67 72 16 36 24 31 20
East 37 50 51 53 56 61 50 35 28 21 24 23
West 70 54 60 59 58 59 56 54 40 42 39 28
Central 44 55 51 59 51 68 55 43 40 33 26 28

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 Mar 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 61 63 66 68 68 67 66 65 67 68 71 74
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 80 86 94 102 104 106 105 99 88 77 74 70



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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