For one month every year, Singapore takes a hiatus from its reputation as a squeaky clean city to feed the hungry ghosts during the annual Chinese festival.
During Hungry Ghost Month, the seventh month on the Chinese lunar calendar, the gates of hell open, allowing the ancestors' ghosts wander the earth, according to Chinese tradition. The ghosts are either honored or appeased -- depending upon their character -- with offerings of food, incense and the burning of paper effigies of money or other gifts.
Singapore may present a modern, often Western-appearing, facade of gleaming office buildings and high-rise apartment buildings, but it hasn't let go of the tradition.
Its holiday offerings add up to a substantial sum. The city-state imported more than 21 million Singapore dollars-worth ($16.8 million) of joss paper from January to June this year as well as nearly 3 million Singapore dollars-worth of religious scented powders and incense, according to data from International Enterprise Singapore, a government agency.
The city-state -- the only country considered a developed market in Southeast Asia -- backs up its reputation for cleanliness with fines as high as $10,000 Singapore dollars for littering, but when it comes to the ancestors, Singaporeans give the rules a wink. Many eschew the specialized bins set out on public housing estates for burning joss paper, leaving the remains of their offerings at various locations throughout parks and residential areas.
Stepping on or cleaning up the offerings could anger spirits, who may follow the offender home, according to tradition.
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To be sure, Singaporeans may get messy with their burning, but they don't appear to get careless. The Civil Defence Force, which takes responsibility for fighting fires, noted that there's no uptrend in incidents it responds to during the holiday period and in fact, the total number of fires it responds to has been trending downward for years.
It's difficult to tease out whether the burning during Hungry Ghost Month causes more hospital or doctor visits. The holiday period coincides with the "haze season," when neighboring countries clear rain forests by burning, sending smoke wafting over the city-state. Data from one hospital, Changi General, suggests there isn't much difference in the number of respiratory cases there before and during the holiday period.
But some patients may avoid the hospitals out of concern that spirits could be more active there.
"From our experience in the hospitals, patients would tend to put off elective surgeries," said Dr. Clarence Yeo of the Killiney Family & Wellness Clinic. But he noted, "For emergencies, they will still go."
He tends to see more patients at his clinic with respiratory conditions, such as allergies, over the period.
But the tradition of offerings may be waning somewhat.
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"In the past, there was more burning around. Almost everywhere you go, you'd see incense paper on the floor, grass, trees and roads. Piles of ashes could be seen along the walking paths too," Linsay Tan, a 22-year-old student, said via email.
While as a child she practiced burning offerings and became a vegetarian for the month, "for the past five years, at least, I don't really celebrate this festival," she said.
Others also noted that the festival isn't as compelling for the younger generation.
"Personally I don't [make offerings], but my parents and the generation before did," Dr. Yeo said. "For the younger generations, they are maybe not so familiar with the festival. It won't make much difference to them."
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Many may now focus less on superstitious aspects -- such as appeasing angry spirits -- and more on offerings to the ancestors. But Dr. Yeo doesn't expect the festival will vanish.
"In some Asian or Chinese families which are still quite traditional, then the tradition tends to carry on. It's been around for hundreds of years. I don't think it will die off," he said.
Indeed, the success of the 2005 horror film The Maid, one of the offerings of Singapore's small film industry and the recipient of a European film award, suggests the holiday isn't likely to lose too much of its attraction. The film, written and directed by Kelvin Tong, broke the city-state's box office record for horror films on its opening weekend. It follows a Philippine domestic helper as she arrives in Singapore during Hungry Ghost month and makes the mistake of stepping on the ashes of a burnt offering, spurring one of the less-than-benevolent spirits to latch on to her.
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Modern Singapore cares enough for its ghosts that Tong revisited them in his 2007 comedy Men in White, although the film was panned by critics.
The gates of hell are set to close on August 24 this year. The final day generally brings a spurt of offerings meant to entice the hungry ghosts back to the other side of the fence.
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1