Unhealthy Air for Sunday’s Singapore Grand Prix

The sprint already ran in this air. Sunday’s race is the one left, and the forecast for it is unhealthy.

At 6 p.m. Saturday in Singapore, the National Environment Agency put the 24-hour Pollutant Standards Index between 118 and 168. On the published scale, that is unhealthy. The forecast for the next 24 hours, which covers the race, is unhealthy to “high unhealthy,” the agency’s phrase for the upper part of that band. Moderate to dense smoke from southern Sumatra was drifting toward the city, and more smoke was sitting over Kalimantan. Afternoon showers eased the readings a little. They do not put those fires out.

If you are in the city for the race, decide how long you will be outdoors, and who in your group should sit the long stretch out.

Very unhealthy starts at 201. Unhealthy is the band under that, from 101 to 200. Saturday evening’s forecast stays under 201 and puts Sunday in the upper part of unhealthy.

Friday came closer. CNA, the Singapore broadcaster, reported a central reading of 192 at 5 p.m. Friday, called it the highest of this year’s haze season, and said the agency had warned the 24-hour figure could cross 200. By Saturday evening the citywide range had eased. It had not evened out. An hour after the bulletin, the news site AsiaOne mapped 7 p.m. readings of 118 in the north and 186 in the central region. The circuit is in the central region. Use that reading.

The one-hour PM2.5 figure is the fine-particle count for the air right now. At 6 p.m. it was 63 to 107 micrograms per cubic meter, an elevated band. CNA said the central one-hour reading hit 151 at 3 p.m., a high band, and then dropped. Use the one-hour figure for the next walk. Use the 24-hour forecast for a night at the circuit.

The ASEAN Specialised Meteorological Centre tracks this smoke across Southeast Asia. Its Saturday afternoon update had moderate haze over Singapore, Peninsular Malaysia, and parts of Borneo and Sumatra. Many stations in that wider plume were unhealthy, and some had reached hazardous. Singapore’s Saturday evening reading stayed unhealthy. The wind is from the east-southeast or the south. A shower over the city on Sunday will not clear the fires upwind, and those areas are expected to stay dry.

Sunday’s race is scheduled for 8 p.m. at the Marina Bay Street Circuit. That is 8 a.m. Sunday on the U.S. East Coast and 5 a.m. on the West Coast. On Formula 1’s timetable the grand prix runs about two hours, sunset is 6:53 p.m., and the drivers’ parade is from 6 to 6:30. Anyone who comes for the afternoon will be outside well before the start.

The entertainment stays as listed. Adam Firth, executive director of Singapore GP, said in a Saturday morning statement, carried by Bernama, Malaysia’s national news agency, that the promoter had no plans to modify it. Any change would be posted on official channels. The Singapore Tourism Board told Bernama, the same morning, that it is watching the weekend with the promoter and the Haze Task Force, the government group that steps in when the haze gets worse.

The circuit will tell spectators what the air is doing. Medical help and N95 masks will be on site if the haze requires them. The board would take up a change to the event only if haze created a problem with visibility, public health, or operations, and it would decide that with the promoter. That is where the promoter and the tourism board stood on Saturday morning. The evening forecast was unhealthy, under the 201 line where the health advice changes.

Singapore’s Ministry of Health splits an unhealthy reading by who you are. A healthy adult should cut back on prolonged or strenuous time outdoors. Prolonged means several hours without a break. Older adults, pregnant women, and children should make that kind of outing as short as they can. Anyone with chronic heart or lung disease should skip a several-hour stretch outside.

A seat from late afternoon through a finish around 10 p.m. is that stretch, even if you spend it standing. A short walk is a different case. For a healthy person, a few days of this air generally means irritated eyes, nose, and throat. A healthy person can skip an N95 on a commute or a short walk between buildings. The ministry brings that mask in when a healthy person will be outside for several hours and the index is hazardous, above 300. For older adults, pregnant women, and people with heart or lung disease, the mask comes up if they have to be out for several hours once the air is very unhealthy. On this forecast, anyone in that group should plan a shorter stay. Bring a mask if you want one before the circuit makes them available. Drink water. A scratchy throat is the symptom the ministry names, and it is a reason to cut the open hours.

If the 24-hour reading crosses 201, the lines change. Healthy people should avoid a long outdoor exertion. Older adults, pregnant women, and children should keep outdoor time to a minimum. People with heart or lung disease should stay inside. The table is on the Ministry of Health site and on haze.gov.sg.

Open NEA’s myENV app, or haze.gov.sg, before you leave the room. The one-hour PM2.5 reading is for the next hour. The 24-hour forecast is for the race. Read the central number. On Saturday night the north was the mild one, and the circuit is in the central region.

If Sunday afternoon was going to be a long walk outdoors, move it under a roof: a mall, a museum, a hawker centre. Go to the race, and skip the long afternoon outside. If Singapore GP changes the night, it will say so on its own channels.

Look once more on Sunday afternoon, Singapore time, before the walk to the gate. Between 101 and 200, go, and spend less of the day outside. Above 201, use the stricter line and decide whether you still want the seat.