Air pollution warning issued for sensitive groups on Sunday, Monday

Taipei, Dec. 20 (CNA) Northeasterly monsoon winds are set to bring increased pollution to southern and central Taiwan on Sunday and Monday, with sensitive groups advised to avoid outdoor activities, according to the Ministry of Environment (MOENV).

Pollutants from overseas are forecast to bring air quality in central and southern Taiwan to an orange alert level, the ministry said via a press release.

Under the ministry's Air Quality Index (AQI) system, during an orange alert, people with heart, respiratory, or cardiovascular conditions, as well as children and the elderly, are advised to reduce physical exertion and limit outdoor activity or wear a mask when going out.

If otherwise healthy individuals experience eye irritation, coughing, or a sore throat, they should consider reducing outdoor activities. Students can still participate in outdoor activities, but prolonged or intense exercise is not recommended, the ministry said.

Hourly concentrations of fine particulate matter (PM2.5) in China's Shanghai and Shandong areas -- upwind of Taiwan under northeasterly monsoon conditions, making them key indicators for transboundary pollution -- ranged from 100 to 180 micrograms per cubic meter (μg/m3) on Friday, and were continuing to rise, MOENV said.

In Taiwan, the regulatory thresholds for PM2.5 are set at a daily average of 30 μg/m3 and an annual average of 12 μg/m3, according to the ministry.

PM2.5 hourly concentrations could reach 40 to 50 μg/m3 in northern Taiwan early Sunday morning, and as winds shift southward in the afternoon, air quality in most areas is expected to hit an orange alert level, the ministry said.

The impact of transboundary pollution is expected to ease on Monday, but another wave of northeasterly monsoon winds is likely to affect central and southern Taiwan on Wednesday before conditions improve on Thursday.