Only seven out of 77 provinces in Thailand had safe air to breathe and most provinces including the capital were blanketed with red levels of hazardous dust on Wednesday morning.

The Geo-Informatics and Space Technology Development Agency (Gistda) reported at 8am on Wednesday that 39 provinces were blanketed with “red” hazardous-to-health levels of PM2.5.

The PM2.5 levels ranged from 76.5 to 143.1 microgrammes per cubic metre of air over the past 24 hours. The highest level was in Samut Sakhon province, followed by 133.2µg/m³ in Pathum Thani, 129.4µg/m³ in Bangkok, 128.6µg/m³ in Nonthaburi and 125µg/m³ in Ayutthaya.

The government-set safe threshold is 37.5µg/m³.

Thirty-one provinces were covered with orange levels of PM2.5 which were the levels of ultrafine dust that started to affect health. The levels ranged from 41.7 to 73.4µg/m³.

Safe PM2.5 levels ranging 21.2 to 36.4µg/m³ were in Phayao, Ranong, Chiang Rai, Surat Thani, Chumphon, Chiang Mai and Mae Hong Son which recorded the lowest level.