Singapore was hit yesterday by the worst haze since April last year - when the index measuring air quality was tweaked - and the authorities warn that it could deteriorate.
The 24-hour Pollutant Standards Index (PSI) rose through the day to between 132 and 148, in the unhealthy range of 101-200, by 11pm. The three-hour PSI then was 207, in the very unhealthy range.
Last year, the highest three-hour PSI was 153 on Oct 6, and the highest 24-hour PSI was 107-125 on Oct 7.
Those heading to the polls today should expect hazy conditions to persist, said the National Environment Agency yesterday.
The 24-hour PSI is expected to be in the low- to mid-part of the unhealthy range, and may climb if the winds are unfavourable.
Environment and Water Resources Minister Vivian Balakrishnan conveyed Singapore's deep concern over the deteriorating haze situation to Indonesian Minister of Environment and Forestry Siti Nurbaya Bakar yesterday, when the number of hot spots in Sumatra rose from 140 on Wednesday to 328. He called for urgent action to be undertaken, including stricter action against the perpetrators.
Both he and Defence Minister Ng Eng Hen repeated Singapore's offer of help - it had put on standby aircraft and personnel to seed clouds and carry out aerial firefighting, and a firefighting assistance team.
Yesterday, Indonesia sent more than 1,000 soldiers to Sumatra to aid firefighting efforts.
The S-League football match between Albirex Niigata and Tampines Rovers at Jalan Besar Stadium was postponed due to the haze. EtonHouse, which runs 17 pre-schools, suspended outdoor activities once the PSI crossed 100.
Several firms here have started implementing contingency plans.
Doctors also reported a spike of up to 20 per cent in patients with haze-related conditions, such as blocked noses and irritated skin.
Dr Michael Lee, deputy medical director of Raffles Medical Group, said: "We expect to see more patients in the coming weeks if the haze continues to worsen."
Undergraduate Benny Sng, 24, who was sick from the haze, said: "I'm not looking forward to standing in the queue tomorrow even though it is my first time voting. If the air quality worsens, I will take a mask along with me."
The worsening haze has disrupted long-weekend plans for some.
Billing executive Josephine Lim, 49, said: "I had planned to visit the Botanic Gardens with my family on Saturday. But with the haze so bad, I'm planning to stay indoors."
This article was first published on Sept 11, 2015.
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