Hong Kong’s Air Quality Health Index (AQI) health risk category reached “very high” at 8 of the Environmental Protection Department’s (EPD) 18 monitoring stations on Sunday.
The EPD warned that the risk may reach the “high” category or above at some stations into Monday.
“Very high” is the second most severe AQI classification below “serious,” as schools were requested to ensure students’ health.
“Under the influence of a dusty air stream, the background levels of pollutants including suspended particulates are higher than normal,” it said on Monday. “With the monsoon moderating gradually, winds in Hong Kong are expected to weaken and [become] unfavourable to pollutant dispersion in the region, leading to increase in pollution levels.”
On Sunday, the EPD also recommended that vulnerable residents – including children, the elderly, or those with heart or respiratory illnesses – minimise outdoor activity. Employers of outdoor workers were also advised to help protect staff health.
PM2.5 health risk
According to the EPD website, PM2.5 levels were as high as 95.7 in Central as of 7am on Monday.
PM2.5 refers to atmospheric particulate matter measuring less than 2.5 micrometres- about 3 per cent of the diameter of a human hair. As one of the most common units of air quality measurement, studies link PM2.5 to premature mortality, heart or lung diseases, asthma attacks, acute and chronic bronchitis, and other respiratory illnesses.
Air pollution is linked to 6.7 million premature deaths every year, according to the World Health Organization.
According to iqair.com, Hong Kong had the fourth worst AQI rating in the world on Monday morning, behind Lahore in Pakistan, Delhi in India, and Shenzhen in China.
