SINGAPORE, Aug. 19 -- The ghost of the 2019 haze continues to haunt the Singapore Grand Prix.

Seven years after air quality tanked during the race weekend, threatening to derail one of the city-state's most prestigious sporting events, the risk of severe transboundary haze is once again looming.

In September 2019, forest fires in Indonesia sent a thick, pungent smog over the circuit. While 268,000 spectators braved the conditions, organisers were forced to deploy first aiders and distribute N95 masks to a coughing crowd. Today, authorities warn that the risk is even higher.

Currently, the Pollutant Standards Index (PSI) remains in the moderate range of 51 to 100. However, the Meteorological Service Singapore warned on Aug 17 that inten...