Bangkok: Low ventilation rates have caused PM2.5 levels in Bangkok to spike, prompting the Bangkok Governor to closely monitor the air quality situation over the past four days.
According to Thai News Agency, Governor Chatchart Sittipunt observed the situation from the Bangkok Air Quality Information Center in the Din Daeng District, noting that the current PM2.5 levels are the highest this year. Red zone levels, signifying significant health risks, were recorded in four central districts: Bang Rak, Pathum Wan, Sathorn, and Chatuchak, with levels reaching approximately 80 micrograms per cubic meter (µg/m³). Other areas are categorized in the orange zone, indicating initial health effects, leading officials to urge the public to take health precautions, such as wearing PM2.5 masks outdoors and minimizing outdoor activities.
The Governor pointed out that this year's dust issue is different from the previous year. Last year, higher dust levels were observed in the outer eastern areas, like Min Buri and Nong Chok, likely due to burning activities. Currently, the red alert levels have shifted to inner Bangkok, primarily due to vehicular emissions. Construction work on the Skytrain has also contributed to traffic congestion, resulting in increased dust levels, particularly in the mornings.
Recent air pollution levels have been exacerbated by low ventilation rates, described as akin to being in a sealed room, allowing dust to accumulate. Despite efforts to curb burning activities, some neighboring provinces still experience burning, though cooperation has reduced such instances significantly. The ventilation rate last night was notably low, averaging about 200 square meters per second, well below the 2,000 square meter threshold necessary to disperse the dust. However, an improvement in the ventilation rate is expected today.
Despite the current situation, no additional measures have been announced beyond the previous Work from Home directive, as the air quality is anticipated to improve shortly. From January 15, 2026, the situation is expected to improve significantly. Governor Sittipunt highlighted that the overall air pollution situation this year is better than last year, with fewer days in the orange level compared to January 2025, due to the cooperation of various agencies. Nonetheless, vehicular emissions and traffic remain primary concerns that require collective action to address.