Pollution levels reached an all-time high Friday in Singapore due to plantation fires burning in neighboring Indonesia.
Some people began venturing out onto the streets Sunday, many wearing filter masks to block out the foul-smelling fumes, CNN reported.
Philip Eng, a professor of respiratory medicine at Mt. Elizabeth Medical Centre said he's seen an uptick in patients -- particularly among the elderly -- complaining of respiratory problems since the haze overwhelmed the region.
"But we are still in early days," he said. "If this thing drags on for a month, I won't be surprised if more people get hospitalized."
The economic impact of the haze could be in the hundreds of millions of dollars, Asia-Pacific brokerage firm CSLA said.
The economy took a $300 million hit in lost tourist income, closed offices and construction downtime in 1997, the last time Singapore had high pollution levels.