Bangkok on alert for air pollution (Photo: Reuters)

Hanoi (VNA) – Residents in Bangkok, Thailand were warned on February 8 the city’s air quality had hit dangerous levels just days after the country’s pollution control agency (PCD) appealed to residents to wear face masks.

Air pollution in the Thai capital has come under increasing scrutiny in recent weeks with residents complaining of smog and respiratory problems. Some schools were closed on February 8 or kept children indoors.

The Pollution Control Department reported the Air Quality Index (AQI) in central Bangkok area had reached an unhealthy level of 135 AQI by early afternoon of February 8.|

The AQI formulas usually include up to six main pollutants including PM2.5, PM10, carbon monoxide, sulfur dioxide, nitrogen dioxide and ground level ozone.

The department reported PM2.5 dust in Bangkok downtown at mid-day on February 8 at 72-95 micrograms per m3, surpassing the safe level recommended by the World Health Organisation (WHO) by 7-9 times.-VNA