SERIAN, MALAYSIA – An air-quality emergency has gripped the town of Serian in Malaysia's Sarawak state on Borneo island, prompting authorities to declare a state of emergency as acrid smoke blankets the region. The haze, fueled by transboundary smoke from Indonesia's widespread forest and peatland fires, has pushed air pollution readings to hazardous levels, exceeding the critical threshold of 500 on the Air Pollutant Index (API) and peaking at 512.

Under Malaysian guidelines, API levels above 300 are classified as hazardous, and readings beyond 500 typically trigger consideration of a local emergency. The declaration of emergency in Serian means that government and private offices, plantations, construction sites, and quarries will be closed, with only essential services remaining operational. Schools in the Serian division have also been ordered to close from Monday until at least the end of the following week, affecting 647 educational institutions.

Residents of Serian, located about 65 kilometers (40 miles) southeast of Sarawak's capital, Kuching, have described the pervasive smoke seeping into their homes and making outdoor activities difficult. Many are limiting their time outside, with some reporting health issues such as shortness of breath and sore throats. The haze has also impacted local commerce, with markets seeing fewer customers and roadside vendors experiencing a decline in sales.

Authorities have launched cloud-seeding operations in an effort to induce rainfall and alleviate the smog. While recent rain brought some temporary respite, with API levels dropping to 219, the state of emergency in Serian remains in place.

The current haze crisis is attributed to widespread fires in Indonesia's Kalimantan and Sumatra regions, exacerbated by dry conditions and land-clearing practices, including slash-and-burn methods for agricultural purposes like palm oil and pulpwood production. This transboundary haze is a recurring seasonal problem in Southeast Asia, with this year's episode being particularly severe, comparable to the 2015 crisis. The pollution has also affected neighboring countries such as Brunei, Singapore, and the Philippines.

The Malaysian government has stated it will send a diplomatic note to Indonesia, requesting immediate action to extinguish the forest fires. Meanwhile, health ministries across the region have reported a significant increase in respiratory illnesses, including asthma and conjunctivitis, as a result of the poor air quality.