BBC visits wildfire front in haze-choked Indonesia

Indonesia is battling its worst wildfire season in a decade. The fires are producing toxic haze, which is choking millions of residents across the region. This matters because the smoke has made air pollution dangerous and has created a major public-health emergency.

Central Kalimantan is an Indonesian region on the island of Borneo. The BBC’s Liza Tambunan is there at the wildfire front, documenting conditions as pollution levels plunge to hazardous levels. The article presents the region as one of the crisis’s main reporting locations.

The crisis is not confined to the fire zones. The haze has been linked to hundreds of thousands of respiratory illnesses in Indonesia. It has also drifted into neighbouring Singapore and Malaysia, showing how fires in one part of Southeast Asia can affect people across borders. The article does not give a forecast for when the fires or haze will end.

Toxic haze is a layer of polluted air containing smoke, gases, and tiny particles released by fires. It matters because people can inhale these pollutants for hours or days, even when flames are far away. The article describes haze choking millions and says pollution levels in central Kalimantan have become hazardous.

Fine particles, especially PM2.5, are small enough to pass beyond the body’s upper-airway filters. They can reach deep lung tissue and trigger inflammation. Smoke gases can also irritate the eyes, nose, throat, and lungs. Wind can spread this mixture over large areas, making outdoor air unsafe. These details explain the health risk; the article itself does not define toxic haze chemically.

Hazard ratings usually combine measured pollutant concentrations with health guidance. As pollution rises, authorities may advise people to reduce outdoor activity or protect vulnerable groups. In this crisis, the reported respiratory illnesses show that haze is not merely unpleasant visibility loss. It is a serious exposure problem.

The crisis affects millions of people, according to the article. It does not provide an exact exposed population, but it says toxic haze is choking millions of residents in the region. That scale makes the wildfires a regional public-health crisis rather than a local emergency.

In Indonesia, the haze has been linked to hundreds of thousands of respiratory illnesses. The article does not specify whether this figure represents hospital visits, diagnoses, or all reported cases. It also says the haze has drifted to neighbouring Singapore and Malaysia, extending the crisis beyond Indonesia’s borders.

The figures show two dimensions of the emergency: widespread exposure and substantial health effects. Indonesia is the country where the illnesses are reported, while Singapore and Malaysia are named as neighbouring countries affected by drifting haze. The article gives no separate illness totals for those two countries and no precise number for all exposed residents.

Prolonged wildfire-smoke exposure can irritate the eyes, nose, throat, and lungs. It can cause coughing, wheezing, shortness of breath, chest irritation, and reduced lung function. The article reports hundreds of thousands of respiratory illnesses linked to Indonesia’s haze, but it does not identify particular diagnoses.

The most dangerous component is often fine particulate matter. These tiny particles can reach deep into the lungs and trigger inflammation. Smoke can worsen asthma and chronic obstructive pulmonary disease. It can also increase the risk of respiratory infections and place extra strain on the heart, especially among older adults, children, pregnant people, and those with existing illnesses. These specific health effects come from established medical knowledge, not the article’s detailed wording.

Risk depends on concentration, duration, and personal vulnerability. People close to persistent smoke face greater exposure than those briefly encountering haze. Indonesia’s current crisis demonstrates the population-level consequence: respiratory illness has reached hundreds of thousands of reported cases, while millions remain exposed.

Wildfire smoke is made partly of airborne particles and gases that can remain suspended in the atmosphere. Winds can carry this pollution hundreds of kilometres, sometimes across national borders. That is why a fire burning in Indonesia can affect air quality in Singapore and Malaysia. The article confirms the cross-border movement but does not explain the atmospheric process.

When smoke rises, regional winds transport it downwind. Weather conditions can keep pollutants concentrated near the ground, where people breathe them. Large or persistent fires release more pollution and can create a wider plume. The exact direction and intensity depend on wind patterns, rainfall, fire size, and the height of the smoke.

The result is a regional haze problem rather than an isolated Indonesian one. Singapore and Malaysia can experience unhealthy air even though the fires are elsewhere. Cross-border pollution also makes cooperation important, because monitoring and reducing exposure may require action by several countries. The article does not describe any regional response or forecast.

Large fires in Indonesia are often associated with land clearing because burning vegetation can quickly remove forests, brush, or agricultural waste. This explanation comes from established knowledge, not from the supplied article, which describes the wildfire crisis but does not identify its causes. The practice can become dangerous when fires escape intended boundaries.

Peatlands are water-rich soils made from partly decomposed plant material. When drained for development or farming, they can dry out and become highly combustible. Peat fires may smoulder below the surface, resist extinguishing, and produce thick, persistent smoke. This mechanism helps explain why fires can continue and why haze can become widespread, although the article does not mention peatlands.

The consequences extend beyond burned land. Smoke from extensive fires can worsen air quality and affect neighbouring countries. Preventing fires generally requires keeping peatlands wet, managing land clearing safely, and enforcing regulations. Those prevention measures are broader context; the article itself only states the scale, hazardous pollution, illnesses, and regional spread.

Air pollution is measured with monitoring instruments that detect pollutants such as fine particles, ozone, nitrogen dioxide, and sulfur dioxide. Results may be reported as concentrations, often in micrograms per cubic metre, or converted into an air-quality index. Higher readings indicate greater health risk. The article only states that pollution levels in central Kalimantan are hazardous; it gives no measurement method or number.

Fine particles, especially PM2.5, are dangerous because they are small enough to pass deep into the respiratory system. They can reach lung tissue, trigger inflammation, and sometimes enter the bloodstream. Wildfire smoke also contains irritating gases and other particles. The exact mixture changes with the material burned and the fire’s conditions. These technical details come from established environmental-health knowledge.

Measurements help officials communicate danger and guide public behaviour. A hazardous reading can support advice to limit outdoor exposure, particularly for vulnerable people. In Indonesia, the urgency is clear from the reported respiratory illnesses and the haze’s spread to Singapore and Malaysia.