Some 40,000 pupils across the country sat the first paper of the Primary School Leaving Examination yesterday, despite the haze hovering at the high end of the unhealthy range.
The Primary 6 pupils took the English language paper in the morning, many of them in air-conditioned halls and classrooms with air purifiers.
The 24-hour Pollutant Standards Index (PSI) at 7am yesterday stayed in the unhealthy zone, ranging between 152 and 195 across different parts of the island.
The Ministry of Education (MOE) and the Singapore Examinations and Assessment Board (SEAB) said last night in a joint statement that there was no "significant difference in the number of absentees compared to previous years". They, however, said there were about 100 pupils - a small proportion of the total number - who reported feeling unwell yesterday, but could still take the exam.
MOE and SEAB also said pupils who felt unwell and had informed their schools before the start of the paper were placed in air-conditioned rooms with air purifiers to take the exam.
"All candidates can be assured that they will not be penalised or disadvantaged if they were unwell during the examinations."
There had been concern earlier that the PSLE, which ends next Wednesday, would be delayed if the haze got worse.
Schools here were closed last Friday as a precaution, as the 24-hour PSI levels were near hazardous levels. But they reopened on Monday, with schools taking measures should the air quality deteriorate.
The National Environment Agency said yesterday that haze continues to be blown here by the prevailing south-easterly winds.
For today, the prevailing winds are forecast to blow from the south-east or south, and hazy conditions are still expected, it said.
The 24-hour PSI for today is expected to be between the high end of the unhealthy range and mid-section of the very unhealthy range, and may deteriorate to the high end of the very unhealthy range if denser haze is blown in.
Principals said the first day of the PSLE went smoothly.
Madam Vimi D. Sambwani, principal of Corporation Primary School, said the pupils took their papers in rooms equipped with air purifiers and extra fans. Invigilators also checked the pupils' medical conditions before the exam started and were vigilant throughout.
White Sands Primary principal Ng Teng Joo said no pupil was unwell or absent at his school for the PSLE exam because of the haze.
Madam Zalina Ibrahim, 36, a housewife with a Primary 6 son in Yumin Primary School, said: "I believe the schools have measures to protect the kids. Their health cannot be compromised even in a national exam."
Housewife Julia Wee, 44, whose Primary 6 daughter is in Raffles Girls' Primary School, said: "If the PSLE had been delayed, it might affect the arrangement for children in other levels who are also going to take their exams."
"It's good that the teachers have been keeping us updated regularly about precautionary measures and any changes because of the haze."