SINGAPORE (Reuters) - A smoky, 'unhealthy' haze has drifted over Singapore this week clouding the build-up to the city-state's glamour sporting spectacle - the Formula One night race.
Singapore's National Environment Agency (NEA) said air pollution had risen into the unhealthy range on Thursday after a wind change had brought smoke from forest fires on Indonesia's Sumatra island.
The three-hour Pollution Standards Index rose above 100, the level at which the air is deemed unhealthy, at 3pm local time (0800 BST) on Thursday and continued to rise when the next two hourly readings were published.
The NEA advised on their website that "healthy people" should "reduce prolonged or strenuous outdoor physical exertion" when the haze levels reach over 100, which also happened on Monday.
The Williams team said in a preview of Sunday's race that the heat, humidity and length of the Singapore grand prix made it one of the most arduous on the Formula One calendar, with drivers losing over three kilogrammes over the 61 laps.
Rain is forecast over the next four days which should help reduce the pollution levels but race organisers said they would be monitoring the problem.
"In the event that the haze caused visibility, public health or operational issues, Singapore GP would work closely with the relevant agencies before making any collective decisions regarding the event," a Singapore GP spokesperson said.
Last year, smoke smothered Singapore, with pollution index levels reaching a record 401 in June. A mark over 300 is deemed hazardous.
In August, Singapore's parliament passed a bill proposing fines for companies that cause pollution regardless of whether the companies operate on the island, though it remains to be seen how the law can be enforced.
Editing by Amlan Chakraborty