The smoke has now triggered ASEAN's highest haze alert

The fires burning in Kalimantan and Sumatra have stopped being an Indonesian problem. ASEAN has switched on its Level 3 haze alert, the highest setting it has, after smoke crossed into Brunei, Singapore and peninsular Malaysia. Al Jazeera reports that Malaysian Borneo is taking the worst of it: Kuching read 407 on the air quality scale and Serian, close to the Kalimantan border, read 408, with six places in Sarawak above the 300 mark that counts as hazardous. Sarawak called off its outdoor Independence Day events. Deputy Premier Douglas Uggah Embas said that if readings pass 500, only essential services will be allowed to open.

The health numbers moved fast. In Sarawak, asthma cases went from 219 in one week to 1,811 in the week of 23 to 29 August, and cases of conjunctivitis, the eye infection often called pink eye, rose from 146 to 720. Mia Emylia Hassan, a mother in Kuching, told Al Jazeera that she has not seen blue sky in over a month and that every trip to the emergency room with her child feels like "a mini heart attack". Inside Indonesia the readings are worse still, at 780 in Palangkaraya and 593 in Pontianak, and the Health Ministry now counts 5.5 million people directly exposed to the smoke on Borneo and Sumatra and 13,500 treated for respiratory infections across July and August.

More than 200,000 hectares have burned since January, almost 95,000 of them in July alone, and police have arrested 72 people on suspicion of setting fires. Malaysian atmospheric scientist Jayaprakash Muralitharan said the strong El Nino has dried out the peat so thoroughly that firefighting is only a holding action, and that the smoke will likely last until the rains arrive at the end of September or in October.

Why it matters

For anyone in the fire provinces, the practical news is the timeline: the people who study this expect weeks more of smoke, not days, so plan your masks, indoor time and clinic visits around a month rather than a weekend. For Indonesia the cost is now diplomatic as well as medical, because a Level 3 alert makes this a regional emergency with Jakarta named as the source, and it lands while Indonesia is asking its neighbours for trade and investment deals.