Singapore's skies cleared Friday and air quality improved as smog from raging Indonesian forest fires drifted away, easing fears that this weekend's Formula One race may be affected.
The blazes have been spewing toxic haze across Southeast Asia, forcing the closure of schools and airports, and prompting Jakarta to deploy thousands of personnel to tackle them.
The Indonesian fires are an annual problem during the dry season when farmers use illegal slash-and-burn techniques to clear land for agriculture, but this year's fires are the worst since 2015.
Thick smog had been hanging over Singapore since last weekend, pushing air quality to unhealthy levels, obscuring the waterfront skyline and sparking fears that Sunday's showpiece F1 night race may be knocked off track.
But on Friday the skies were largely clear, with only a light haze over the city, while air quality improved to a "moderate" level of around 65 on the National Environment Agency's scale.
A reading between 101 and 200 indicates unhealthy air quality.
The wind direction could however still change ahead of the weekend and push smog back over Singapore.
F1 organisers say they have a contingency plan if the haze worsens and have been stocking up on face masks to protect against pollution which spectators can buy at the circuit.
Indonesia, and its neighbours Malaysia and Singapore, have been worst affected by smog but it is starting to spread over a wider area in Southeast Asia.
Haze was detected Friday in central and southern parts of the Philippines, prompting health officials to warn people in affected areas to keep outdoor activities to a minimum and wear masks.
The blazes are centred on Indonesia's Sumatra island and the Indonesian part of Borneo island. Borneo is shared between Indonesia, Malaysia and Brunei.
Thousands of schools have been forced to close in Malaysia and Indonesia amid mounting health concerns, while several airports have shut due to poor visibility.
Run on face masks
People have been dashing to buy face masks and there has been an increase in reports of respiratory illnesses and conditions such as dry and itchy eyes.
The worst-affected part of Malaysia has been Sarawak state, on Borneo, where more than 1,000 schools were shuttered Friday and air quality reached "hazardous" levels in one area bordering Indonesia.
The second round of an Asian Development Tour golf tournament in the state, the PGM MNRB ADT Championship, was postponed for a second consecutive day Friday due to the haze, organisers said. It is expected to start Saturday.
Over 2,800 "hotspots" – areas of intense heat detected by satellite indicating a likely fire – were sighted Friday in two provinces of Indonesian Borneo alone, although the number dropped in Riau, Indonesia's disaster agency said.
Indonesia insists it is doing all it can and has deployed about 29,000 personnel from a range of government agencies nationwide in an effort to douse the blazes, many of which burn underground in carbon-rich peat.
Almost 250 people have been arrested on suspicion of activities that led to the blazes.
But experts say the fires are unlikely to be extinguished until the onset of the rainy season in October and have raised fears of a repeat of the 2015 crisis, the worst smog outbreak for about two decades.
In many places the current haze "is comparable to 2015 at the same time of the year," Robert Field, a scientist from NASA Goddard Institute for Space Studies, who tracks Indonesia's fire seasons, said.
A major problem for firefighters "is that once underground and into the peat (the fires) are very difficult to put out and have, for all intents and purposes, an inexhaustible supply of fuel," he said.
"They'll only be put out with the return of monsoon rains." - AFP