Too many air quality indicators may complicate public messaging on haze: Grace Fu

The NEA provides two indicators of air quality to help people plan their activities: a PSI forecast for the next 24 hours, and an hourly PM2.5 reading.

PM2.5 are small particles that are the dominant pollutant during transboundary haze episodes.

The 24-hour PSI forecast indicates what the air quality is expected to be in the next 24 hours and can be used to plan activities ahead of time.

The forecast takes into account the prevailing air quality, local and regional weather conditions, and the regional hotspot and haze situation assessed through satellite imagery, said Fu.

Meanwhile, PM2.5 readings refer to concentrations of the dominant pollutant particle during haze episodes. It provides a more reflective indicator of current air quality.

It is based on the readings from 23 air quality monitoring stations installed across the country.

People should refer to the PM2.5 values for planning their immediate activities, and to the PSI forecast if they are planning an outdoor activity the next day.

The NEA will continue to review how its forecasting and public information services can be enhanced to provide more useful guidance, said Fu, adding that providing timely and reliable information is an important part of her ministry’s public health response.

Fu also said that NEA releases fortnightly forecasts but noted that the forecasts are less accurate as the horizon of the forecasts increases.

The one-hour PM2.5 readings provide the shortest possible forecast and is the “most accurate” in giving the public a sense of the air quality before conducting an activity, she said.

On masks, Fu said the priority of the two distribution exercises had been Singaporeans who are more vulnerable to the health effects of haze, or who may have limited means in collecting free haze masks.

These include seniors, pregnant women, children, individuals with specified medical conditions, holders of Community Health Assist Scheme Orange and Blue card, those with Medical Fee Exemption Card, and those who are on ComCare.

“This ensures that assistance reaches those who need more support,” she said in response to several MPs who had asked about the considerations involved in determining mask eligibility.

N95 or equivalent masks are generally not required when a person is indoors, or outdoors for short periods, such as when commuting.

In the case of haze, there is no risk of people-to-people transmission which would have required all Singaporeans to be masked up as soon as possible, said Fu.

The criterion for eligibility to collect the masks was expanded in the second round that started on Oct 23, with all Singaporeans aged 60 and above allowed to pick up the face coverings. In the first round, only seniors aged 67 and above were eligible.

Close to one-third of Singaporeans are eligible under the expanded criteria, she said, adding that close to 30% of them had collected their masks as at Oct 29.

“We will continue to review the scale and eligibility of distribution as conditions evolve, and are prepared to expand support if necessary,” she added.

Nadia Ahmad Samdin (Ang Mo Kio GRC) also raised questions on whether the ministry has assessed the impact of prolonged haze on agricultural productivity locally and in Singapore’s food import sources, and if there are risks to food supply resilience and affordability here.

Fu said that the recent haze has not affected Singapore’s food supply.

“Singapore imports food from more than 180 countries and regions. Sourcing broadly helps to reduce concentration risks and enables industry to switch to alternative sources when needed,” she added.

While wholesalers have given feedback that prolonged haze may impact vegetable growth, Fu said that for local farms, the overall impact has generally been “minimal”, with operations returning to normal following the recent improvement in air quality.

The Singapore Food Agency will continue to monitor the impact on food supply and implement measures to address concerns as necessary, she said.

Fu also noted that while the haze has affected footfall at hawker centres and markets, this is compensated by increase in takeaway orders.

She added that NEA will continue to monitor the impact on hawkers, although there is currently no plan to introduce additional haze-specific financial assistance.