As smoke from Indonesian wildfires blankets Malaysian Borneo, residents like Elaine Sim in Kuching wear masks and buy air purifiers. The Air Quality Index in Kuching reached 457, hazardous levels, while Serian recorded an A. Q.

I. of 832. The Malaysian government has spent over $100,000 on cloud seeding missions. Aboard a Royal Malaysian Air Force Lockheed C-130H-30 Hercules, crews release a mix of salt and water into clouds to encourage rainfall.

Meteorologists remain divided on its effectiveness. Near the Batang Ai dam, light rain followed a mission, but experts say lasting relief requires controlling the fires at their source in Indonesian Borneo.