Bangkok staffers try to clean the city in a bid to relieve the haze severity. Credit: BMA

Bangkok’s air expected to improve over the weekend with less air inversion

The capital has been hit hard by haze today with the maximum PM 2.5 concentration levels in 24 hours being over 100 micrograms per cubic meter, defined as the hazardous threshold, while other parts of the country except the South have also felt the air pollution following the effects of the ongoing air inversion

The Pollution Control Department (PCD) has reported the sharp increase of haze caused by PM 2.5 in the capital today, of which its maximum concentration being beyond the hazardous threshold defined in the national agenda.

The department said the fine dust particles in the air in Bangkok were measured at between 44 to 111 micrograms per cu m, which means almost all of its areas have been blanketed by the haze, with the levels that start to “affect” health.

The PM 2.5 safety limit within 24 hours is set at no more than 50 micrograms per cu m. Anything beyond that are the levels, which “start to affect health” and public members will be warned against outdoor exposure.

Besides Bangkok, other parts of the country have also experienced the high levels of haze today. The department said PM 2.5 concentration levels in the North today were between 31 to 74 micrograms per cu m, prompting eight areas in the region to have haze beyond the limit.

In the West and the East, PM 2.5 concentration levels were around 19-82 micrograms per cu m, and 34-56 micrograms per cu m, prompting almost all of the areas in these two regions choking with haze beyond the limit.

In the Northeast, PM 2.5 concentration levels were between 32 -97 micrograms per cu m, prompting at least five areas to become critical with choking haze.

However, based on its air quality modelling, the department expects that the situation would improve over the next few days as the air inversion would become less tense, with winds blowing more.

The air inversion

The country is experiencing the inversion, but the next few days, the phenomenon is expected to become less tense, prompting winds to blow and the haze disperses.

The Bangkok Metropolitan Administration said it has been trying hard to reduce sources of the pollution, mainly from incomplete diesel-based engine combusion, by screening trucks travelling into the city. However, it has also contributed the cause of the poor air quality to the air inversion.

While the city is busy with suppressing sources of the air pollution in the city, the Ministry of Natural Resources and Environment as well as the PCD have been attempting to suppress the sources of haze in the North, which is considered as being critical annually.

This year, the ministry has introduced some initiatives to convince the locals there to help in fuel management by introducing some economic incentives for helping collect forest biomass materials and farm residues in advance to reduce fuels before forest fires strike during a dry season.

It has coordinated with the Interior Ministry as well as governors nationwide via the video conference yesterday, asking them to implement the ad-hoc air pollution resolution plan approved by the Cabinet in November last year, which focuses specially in areas with regular forest fires in the North.

This includes collection of fuel materials in advance and scheduled burning to create fire buffers, which incorporates local participation.

Environment Minister Varawut Silpa-archa said his ministry would act as a supporter of the efforts by providing supportive data collected principally by the PCD and agencies under its supervision in the areas.

Thailand has been experiencing haze seriously over the past few years since it has come up with better air pollution measurements, which have exposed exceeding levels of dust particles harmful to people’s health like PM 2.5 both in the capital and other regions.

Since, the issue has been addressed as a national agenda, which directs comprehensive planning aimed to tackle the sources of the air pollution, which are different among regions.

For instance, in the capital, the main sources of the haze are incomplete combusion of car engines, especially diesel-based vehicles, intensive construction, as well as pre-harvest burning of sugarcane leaves in provinces in the Central Plain.

In the North, on the other hand, the main sources of the air pollution are farm clearing and forest burning.

The situation is often exacerbated by bad weather, created by an air inversion, under which a warmer air overlays the cold air and acts as a lid, while the air underneath becomes stagnant, thus the situation which traps the pollution below.

Recently, locals in the North especially in Chiang Mai have tried to come up with changes of work structure and plans so that the situation is dealt better. They have proposed local organisations to act as the central coordinating bodies, rather than waiting for agencies in Bangkok to act for the problem further away.

This is also part of the decentralization of power, under which forest fire control is being transferred to local authorities and organisations. But they are being stuck with limited budgets, seen as among the critical challenges in resolving the haze problem.