The Macao Meteorological and Geophysical Bureau (SMG) will begin to assess Macau’s air quality with new and stricter standards from January 1. The bureau has anticipated that the number of days with bad air quality will be higher as a result of the new standards.
Yesterday, the SMG held a press conference for a briefing on the city’s new Air Quality Index.
The new index follows the latest World Health Organization Air Quality Guidelines (WHO AQG) Global Update 2005.
According to the new definition, air quality with indexes of 0 to 50, 51 to 100, 101 to 200, 201 to 300, 301 to 400, and 401 to 500 will correspond to Good, Moderate, Bad, Very Bad, Severe and Harmful, respectively.
During the press conference, Tang Iu Man, the Deputy Director of the SMG, said that the new standards may lead to the number of air quality days in 2021 growing by approximately 20% compared to that of 2020.
“The number of days with bad air quality may increase once we use the new index,” said Tang. “For example, [in the case of] One Grantai monitor station, the number may increase by 20% after the adoption of the new standards, based on the statistics collected from 2017 and 2018.”
However, Tang reiterated that this does not mean that Macau’s air quality will be worse.
Once the new standards come into effect, the SMG will issue at least four air quality forecasts a day. The validity of each forecast will be extended from current 19 hours to 31 hours. Such changes will give the bureau the flexibility to issue special notifications earlier.
The classification of air quality levels and related content are defined with reference to the classification of countries and regions, including China, Hong Kong, the United States, the United Kingdom and Canada.
The concentration value of all pollutants corresponding to the “good” air quality level is equal to or lower than the “air quality guideline” in the WHO AQG.
Macau’s Air Quality Index is based on the data obtained from the automatic monitoring network. The sub-index of pollutants, including respirable suspended particulate (PM10), fine suspended particulate (PM2.5), nitrogen dioxide (NO2), ozone (O3), sulphur dioxide (SO2) and carbon monoxide (CO), are calculated using their real-time concentrations and related influences on human health.
When the air quality is bad, very bad, severe or harmful, Sensitive Population Groups, namely people with existing heart or respiratory illnesses, pregnant women, children and the elderly, are especially advised to minimize outdoor strenuous activities and their time spent outdoors, especially in areas with heavy traffic.
The general public are advised to do the same.
Poor air quality days dropped by 60%
The SMG official also remarked that, due to the Covid-19 pandemic, the number of days with poor air quality and the volume of air pollutants dropped by approximately 60% compared to last year.
The significant drop was related to the reduced industry and human activities this year.
At the Taipa Hill station, only seven days were registered as having poor air quality from January to October, 19 fewer days than the same period last year.
During the same period, Rua do Campo also reported fewer poor air quality days, only recording 10 days this year, compared to 27 days last year.
Cold wave predicted this week
A cold wave is expected to reach southern China during the middle of this week. The temperature in Macau will drop remarkably below 10 degrees Celsius. It will remain very cold on New Year’s Eve and New Year’s Day. The temperature will further drop to around 6 degrees Celsius. The public is advised to be aware of the change in weather and take precautions against the cold.
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