EXTREMELY small particulate matter, known as PM2.5, is affecting many parts of the country but measures of these hazardous particles are still not part of the official Air Quality Index.

The air pollution monitoring website aqicn.org yesterday revealed a surge in particulate matter with a diameter less than 2.5 microns – PM2.5 – to risky levels in many provinces in the North. However, the Pollution Control Department (PCD) reported that only Tak and Lampang suffered from air pollution higher than the safe limit from the seasonal haze season.

Meanwhile, Greenpeace cautioned that PM2.5 statistics were not shown in the official pollution monitoring system, even though PM2.5 is the major cause of illnesses in respiratory systems and is associated with heart disease and cancer.

Climate and Energy Campaigner for Greenpeace Southeast Asia Chariya Senpong said the increase in the PM2.5 level in the North had gone unnoticed by a majority of people because figures on the air pollution indicator were simply not included in the Air Quality Index.

more High air pollution not revealed as tiny-particle levels left out