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.

“The absence of the PM2.5 figure in the official air pollution indicators keeps the public away from the accurate air pollution situation and puts the health of the general public at risk because they do not know how serious the air pollution is,” Chariya said.

“This causes the misconception that the haze problem or the air pollution is not so severe, but indeed the level of PM2.5 has risen dangerously in many provinces of the North, as well as many major cities and industrial areas.”

According to the international air quality monitoring website aqicn.org, many provinces in the North suffered from extremely high PM2.5 levels. For example, the PM2.5 level in Chiang Mai was 156 micrograms, Chiang Rai was at 151 micrograms, and Lamphun had 153 micrograms as of yesterday, compared to the World Health Organisation’s safe limit at 25 micrograms. However on the PCD’s Air Quality Index, all these three provinces had an average official air-quality level that was not considered hazardous.

The department calculates the official Air Quality Index from PM10, the ozone level, carbon monoxide level, nitrogen dioxide level, and sulphur dioxide level.

Chariya said Greenpeace had been working with the PCD in recent years to include PM2.5 data in the Air Quality Index calculation and publicly disclose the PM2.5 level. However, their efforts have been unsuccessful.

“The PCD has an ability to measure PM2.5 now. They even have PM2.5 measuring devices installed in many provinces, but they still do not use this data, so we still carry on our campaign to encourage the department to disclose this information to the public.”

She also stressed that PM2.5 was not only a problem for the North during burning season, but people in big cities and industrial zones such as Bangkok and Rayong also suffered from PM2.5 without noticing it, because PM2.5 can also be generated by industry, energy, and transport sector sources.

Meanwhile, the head of Chiang Mai’s Provincial Public Health Office, Capt Phuriwat Chokkerd, said there was still no warning for people in the provinces about health hazards from smog, as the air pollution level in Chiang Mai still did not exceed the safe limit. “We are keeping close contact with the PCD on the haze situation and will warn people right away if air pollution is high. But as of now the PM10 level in the province is still below the safe limit and people can still do outdoor activities without harm,” Phuriwat said.