JAKARTA — Pollution from smoke emitted by months of wildfires across Indonesia caused an estimated 3,560 deaths in September, according to a new study by the Centre for Research on Energy and Clean Air (CREA), a Helsinki-based think tank, AFP reported. The same month, about 57.8 million people in Indonesia were inhaling unhealthy-to-hazardous air, CREA said.

Source: AFP via Phys.org

'Worsening air quality due to forest and land fires in Indonesia pushed the estimated death toll to 3,560 cases in September 2026, a twofold increase from the August estimate,' CREA said in a statement on Thursday. The study estimated deaths linked to short-term exposure to fine particle pollution known as PM2.5 — meaning exposure over a matter of days — so the figures are a modelled estimate, not a count of individually recorded deaths.

Source: AFP via Phys.org

CREA put total air-pollution deaths in Indonesia at an estimated 5,310 in September (in a range of 4,610 to 6,080), up 42 percent from 3,740 in August. Fire smoke accounted for 3,560 of them, while chronic non-fire pollution from urban and industrial sources, power generation, transport and waste burning accounted for a further 1,750, according to CREA's own report. The number of people exposed to unhealthy-to-hazardous air hit a monthly record peak of about 58 million in September, a 40 percent jump from August's peak of 41.3 million.

Source: CREA report

Kalimantan and Sumatra hit hardest

Most of the estimated deaths occurred on Indonesia's part of Borneo island — Kalimantan — as well as on Java and Sumatra and in the country's east, AFP reported. Toxic fire smoke accounted for 94 to 99 percent of air-pollution deaths in Kalimantan and more than 80 percent on Sumatra, the regions worst affected by the fires. In September, national population-weighted PM2.5 levels averaged 36 micrograms per cubic metre — more than seven times the World Health Organization's annual guideline of 5 — rising to 10 times the guideline in Sumatra and 24 times in Kalimantan, CREA said.

CREA estimated about 333,470 cases of acute respiratory infection across seven fire-affected provinces, with children aged under five accounting for nearly a quarter of cases. Wildfires had burned more than 1.9 million hectares in the nine months to September, according to the deforestation monitor Nusantara Atlas, cited by AFP.

Call to restore peatlands, not just fight fires

The report argues that Indonesia's government needs to shift from responding to wildfires to restoring peatlands left fire-prone by extensive draining. CREA also said the National Disaster Management Agency's ability to respond was severely constrained by a 75 percent budget cut for 2026, and its report's title says the government is resisting declaring the forest and land fires — known in Indonesia as karhutla — a national emergency. The government has not confirmed or rejected CREA's death estimate, AFP reported.