Singapore's air quality deteriorated to "unhealthy" levels on Saturday for the first time in three years, data from the National Environment Agency showed, threatening to deepen a regional dispute over forest fires.
Every dry season, smoke from fires to clear land for palm oil and pulp and paper plantations in Indonesia clouds the skies over much of the region, raising concerns about public health and worrying tourist operators and airlines.
The 24-hour Pollution Standards Index, which Singapore's NEA uses as a benchmark, was in a range of 87-106 in the afternoon. A reading above 100 is considered unhealthy.