Prime Minister Srettha Thavisin said yesterday that he will call his Cambodian counterpart, Hun Manet, to discuss the transboundary airborne pollution being generated by the many hotspots in Cambodia.

A look at the satellite map shows that most of the relevant hotspots are in Cambodia and the wind is blowing from the east, he added.

On Tuesday, MODIS satellite images showed 644 hotspots in Cambodia. That number has now dropped to 171.

Meanwhile, the Centre for Air Pollution Mitigation reported today that PM2.5 dust in the air in 30 provinces, including Bangkok, exceeds the 37.5 µg/m³ threshold. The other 29 provinces are Nakhon Sawan, Uthai Thani, Chainat, Sing Buri, Lop Buri, Saraburi Ang Thong, Ayutthaya, Kanchanaburi, Ratchaburi, Nakhon Nayok, Sa Kaeo, Chachoengsao, Nong Khai, Nakhon Phanom, Nong Ba Lamphu, Mukdahan, Khon Kaen, Kalasin, Roi-et, Amnat Charoen, Chaiyaphum, Yasothon, Ubon Ratchathani, Si Sa Ket, Nakhon Ratchasima, Buri Ram and Surin.

In Bangkok, 12 areas have excessive level of PM2.5.

Thananchai Wannasuk, chief of the 11th office of the Environment and Pollution Control department, blamed the burning of farm waste as the major cause of the hotspots and the rising PM2.5 levels in north-eastern provinces, such as Nakhon Ratchasima, Chaiyaphum, Buri Ram and Surin.

He said a campaign has been launched to urge farmers not to burn farm waste, but many have simply ignored the call.