Indonesia wildfire haze drives hazardous air pollution across Southeast Asia

Indonesia is facing one of its worst wildfire seasons in a decade. Around 1 million hectares of land have burned so far this year. The fires have sent a toxic haze across Southeast Asia, pushing air pollution to unhealthy levels in parts of Indonesia, Malaysia, Singapore and the Philippines.

In Singapore, the haze has cast a cloud over preparations for the Formula 1 weekend. The 24-hour average air quality has been in the unhealthy range. At one point on Wednesday, Singapore was the world's most polluted major city for a brief period. Reporters in downtown Singapore described a skyline that would normally be clear but was obscured by haze. They said the smell of smoke was in the air and there was a lingering taste in the mouth. Conditions were getting worse hour by hour, with warnings that they could deteriorate further.

More than 300,000 fans are expected in Singapore for the race. Drivers and performers, including The Killers, Zara Larsson, Janet Jackson and Lana Del Rey, are already in the city. Practice was due to begin about 24 hours before Sunday's race. There are concerns about how the pollution will affect drivers, who already face temperatures of up to 60 degrees Celsius in the cockpit, as well as performers who will be on stage for hours and spectators who will be outdoors in 30 degrees Celsius heat for three days.

Public health advice says people should reduce outdoor activity during unhealthy air quality. Children and the elderly, in particular, are advised to stay home. F1 organisers said the race would go ahead as planned without changes. They said there was no risk to the event. Some racegoers may still pack extra masks alongside their earplugs, as well as water.

The worst pollution has been reported in Central Kalimantan. A correspondent outside Palangka Raya described standing in one of the most polluted places in the world. The haze was thick and the smell of burned earth was distinct. Air quality levels had fallen to hazardous numbers because of peatland fires. There was no active fire above ground in the area. Smoke was rising from the earth itself.

Peat fires burn deep underground. They continue to smoulder even after the surface fire has been put out, and they can emerge again. People in Kalimantan have lived with these conditions for months. The government has recorded hundreds of thousands of respiratory cases linked to the fires. The haze has also drifted to neighbouring countries, including Singapore and Malaysia, and parts of the Philippines.