Several areas in Bangkok and neighboring provinces were enveloped in hazardous levels of smog on Tuesday, caused by stagnant air trapping pollution.
The Pollution Control Department reported that levels of particulate matter measuring 2.5 microns and smaller in diameter (PM2.5) surpassed the safe threshold of 35 micrograms per cubic meter over a 24-hour period in certain parts of the capital as well as in Nakhon Pathom, Nonthaburi, Samut Prakan, and Samut Sakhon by 11 a.m. on Tuesday.
In Bangkok, unsafe PM2.5 levels ranged from 37 to 48.8 µg/m³ in various districts, including Bang Bon, Bang Kholaem, Bang Khunthian, Bang Na, Bang Phlad, Bang Rak, Bangkok Noi, Bangkok Yai, Bung Khum, Chatuchak, Chom Thong, Khlong San, Laksi, Nong Khaem, Pathumwan, Phasicharoen, Pomprap Sattrupai, Rat Burana, Samphanthawong, Sathon, Thon Buri, Thawi Watthana, Thung Khru, and Wang Thong Lang. The highest recorded level, at 48.8 µg/m³, was in Sathon district.
In the provinces surrounding Bangkok, unhealthy PM2.5 levels were reported in Krathumban and Muang districts of Samut Sakhon (38.3-53.4 µg/m³), Muang and Phra Pradaeng districts of Samut Prakan (37.9-46 µg/m³), Pak Kret district of Nonthaburi (45.9 µg/m³), and Muang district of Nakhon Pathom (46.1 µg/m³).
The highest level recorded nationwide was outside of Bangkok, at 58.8 µg/m³ in Muang district of Kanchanaburi, while the lowest was 3.2 µg/m³ in Muang district of Phangnga.
The Meteorological Department has indicated that the smog is expected to persist over Greater Bangkok until October 16.