Written Reply to Parliamentary Question on Effect of Elevated PM2.5 Levels on Rail Workers' Health

Mr Melvin Yong Yik Chye asked the Minister for Transport in view of the recent study on air quality in underground train stations in Singapore published on ScienceDirect website 

a.     whether the elevated levels of PM2.5 are an occupational health hazard for rail workers; and 

b.     if so, what are the plans to mitigate the health risk posed to those working in underground train stations and in the train tunnels.

Reply by Minister for Transport S Iswaran:

1.     The 2018 study on air quality referenced by Mr Melvin Yong noted that the air quality in most of our underground train stations was within acceptable limits under the Singapore Standard Code of Practice for Indoor Air Quality for Air- Conditioned Buildings, or SS554. While the PM2.5 levels measured during peak hours at some underground train stations along the North-South and East-West lines exceeded the 24-hour mean exposure limit, the health risk to rail workers is low as they generally spend only four to five hours a day on average at the station platforms.

2.     Notwithstanding, inspection, maintenance, and cleaning of air-conditioning and mechanical ventilation systems are carried out regularly to ensure good ventilation at station platforms. To further improve air quality, more efficient filters that can trap finer dust particles, such as PM2.5, have been installed at station platforms. Air-conditioning systems for underground train stations along the North-South and East-West lines are progressively being upgraded and will be completed by 2025.

3.     As for train tunnels, air quality is regularly monitored to ensure air quality is kept within acceptable limits. Tunnel ventilation fans are deployed to ventilate the tunnels during heavy maintenance works.