Indonesia haze puts 5 million at health risk, official says

Indonesia's wildfire haze has directly exposed more than five million people across Borneo and Sumatra to health risks, deputy health minister Dante Saksono Harbuwono said, as smoke from weeks of fires spread to Malaysia, Singapore and the Philippines.

The fires are concentrated on Borneo and Sumatra and have burned nearly 300,000 hectares of land in Indonesia so far this year, according to an independent estimate from the Nusantara Atlas portal.

Indonesia deployed more than 14,000 firefighters in West Kalimantan. National Disaster Mitigation Agency spokesman Berton Suar Pelita Panjaitan said visibility there fell below one kilometre on Thursday and crews put out fires across nearly 430 hectares. In Central Kalimantan, authorities put out fires across 197 hectares, used a thermal drone to identify underground fire spots and recorded unhealthy air quality with visibility below 2.5 kilometres.

Schools in both provinces were closed and classes moved online. An education ministry official said more than 1.4 million students were attending classes remotely because of worsening air quality.

In Malaysia, the government declared an emergency on Friday in the Serian division of Sarawak after the Air Pollutant Index breached the critical threshold of 500 and peaked at 519. The declaration will close 647 schools from Monday until at least the end of next week.

In the Philippines, air quality was slowly returning to normal after a week of "very unhealthy" and "severely unhealthy" PM 2.5 levels that led officials to close schools in cities and provinces. Singapore's National Environment Agency data showed air quality in the country's central region reached an "unhealthy" level on Friday.

CAMS' Fire Emission Watch portal said fires in Indonesia released more than 23 million metric tons of carbon emissions between August 28 and September 3. It said that was higher than the 20.7 million metric tons recorded over the same period in 2015, a strong El Nino year.

CAMS senior scientist Mark Parrington said Indonesia's recent fire emissions, smoke extent, haze and air-quality impacts were comparable to previous strong El Nino years. Analysts said El Nino has helped create drier conditions in Indonesia, while David Gaveau, founder of Nusantara Atlas, said slash-and-burn land clearing also contributed.

Many fires have occurred on peatlands, which are difficult to extinguish because dry peat can burn underground. NGO Pantau Gambut said more than 210,000 hotspots were detected in peatland areas across Indonesia between January and August.