• Tue
  • Dec 23, 2014
  • Updated: 10:39am
NewsHong Kong
ENVIRONMENT

New air quality index hits highest level on second day

Authorities issue health warning after reading in Causeway Bay, but say Tai Po's was inaccurate

PUBLISHED : Wednesday, 01 January, 2014, 2:36am
UPDATED : Thursday, 02 January, 2014, 7:20pm

The new air quality health index (AQHI) hit its most serious level not once but twice yesterday - though one was a false alarm.

At noon yesterday, the general air quality monitoring station in Tai Po appeared to hit 10+ on the AQHI, the first "serious" air quality health risk reading since the index was launched on Monday.

But the Environmental Protection Department said system adjustments had caused the Tai Po station's incorrect reading.

There were no AQHI readings for that station throughout the day until 6.30pm, when it recorded a 7 on the index.

But at the same time, another 10+ reading was recorded at the roadside monitoring station in Causeway Bay. The department confirmed the reading.

The 6.30pm reading marked the first time the new system hit its highest level.

The department issued its most severe health advice, urging children, the elderly and people with heart or respiratory illnesses to avoid outdoor activities, especially in areas of heavy traffic.

The 12 general monitoring stations recorded AQHI levels of 6 (moderate) to 9 (very high). The other two roadside stations, in Central and Mong Kok, recorded an 8 and a 9, respectively.

The index analyses three-hour average concentrations of ozone, nitrogen dioxide, sulphur dioxide and tiny particles (PM2.5 and PM10), using a scale from 1 to 10, and 10+. It is divided into five health-risk categories - low, moderate, high and very high.

Clean Air Network chief executive Kwong Sum-yin said she was not surprised at the high readings as December was usually a more polluted month.

The pollution was caused by bad roadside air quality mixed with secondary background pollution being blown in from the Pearl River Delta, she said. Seasonal northeast monsoon winds tend to affect southern China during the winter.

Kwong urged the department to carry out more frequent maintenance at monitoring stations to avoid technical failures.

"Citizens may become more wary of the department's readings if there are so many problems," she said, adding that a trial run of the index last week saw at least six malfunctions at various stations.

Video: How to deal with Hong Kong's smog

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newgalileo
Pretty disappointing for Hong Kong not to use the well lnown international standards for air quality, such as AQI (USA and yes, also in Beijing where we also have API, pretty similar). So, is AQI 500 then 10 in HK? That is really confusing or do they want to cover it up?
asiaseen
Clean Air Network chief executive Kwong Sum-yin said "secondary background pollution being blown in by dry monsoon winds from the Pearl River Delta" Pity she does not understand that winter monsoon winds are easterlies and the PRD is to the west. What hope is there in the face of such ignorance.
Dao-Phooy
The new index still makes us search for the only relevant information - the roadside readings. It's so pathetic to place this at the bottom of the list - the Government continues to display its lack of transparency. What was the total cost to taxpayers for this turkey - it hasn't done anything to improve air quality at all! It's simply a huge distraction from the main problem.

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