BANGKOK, Oct. 18 (Xinhua) -- Thailand's Pollution Control Department (PCD) on Wednesday reported unhealthy levels of air pollution in several parts of Bangkok and its surrounding areas as the season change brought the return of excessive dust particles.
Moderate to unhealthy levels of PM 2.5, ranging from 27-55 micrograms per cubic meter, were detected in most areas in the Bangkok Metropolitan Region on Wednesday, according to the data published by the PCD.
The accumulation of PM 2.5 was due to the approaching winter season, which brings high-pressure systems and stagnant air, the PCD said in a statement, adding that an orange alert indicating unsafe levels of the airborne particles would continue for another one to two days.
Effective from June last year, the southeast Asian country revised its national safe limit of PM 2.5 from 50 micrograms per cubic meter over 24 hours down to 37.5 micrograms per cubic meter to be in line with the World Health Organization's standards. ■
