National Environment Agency Our Environment
print Home Anti-Pollution & Radiation Protection Air Pollution Control PSI Pollutant Concentrations

Pollutant Concentrations

Readings on 25 Aug 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 4(2) 52(51) 43(-) 33(14) 0.5(5) 36(78)
South 10(6) 53(52) 27(-) 39(16) 0.5(5) 35(77)
East 13(8) 45(45) 8(-) 53(23) 0.5(5) 35(77)
West 40(25) 54(52) 33(-) 43(18) 0.6(6) 37(80)
Central 6(4) 49(49) 28(-) 50(21) 0.4(4) 32(73)

1-hr PM2.5 (µg/m3)b Readings on 24 Aug 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 30 28 30 26 25 30 32 24 33 32 35 34
South 26 32 33 29 29 26 29 25 21 30 30 29
East 32 32 32 27 31 29 30 29 26 31 32 36
West 25 26 29 30 26 24 26 29 33 33 38 45
Central 24 28 29 25 23 27 23 24 29 24 28 33
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 37 52 57 53 53 43 38 39 38 41 34 29
South 34 45 41 36 50 38 38 34 45 50 53 38
East 43 55 54 38 42 40 37 33 34 32 32 36
West 55 53 53 44 36 35 32 35 39 53 55 42
Central 36 55 47 31 42 29 34 29 35 36 34 34

Note:
a Sub-index for nitrogen dioxide is reported only when the 1-hour concentration exceeds 1130 µg/m3.
b There is no sub-index for 1-h PM2.5.

3-hr PSI Readings from 1am to 12am on 24 Aug 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 69 70 70 70 69 68 68 68 69 69 72 74
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 78 86 91 91 88 83 82 78 78 81 83 82



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.

image description