Much has been made of the annual episodes of transboundary haze from Indonesia, but experts have warned that people also need to pay attention to everyday air pollution generated from a variety of sources, and how it affects them.
For example, contrary to popular belief, a study had found that pollution from road traffic tends to be worse for residential units on the middle floors of a housing block near a road than those on its lower floors, research scientist Dr Erik Velasco from Singapore-MIT Alliance for Research and Technology told reporters on Tuesday (Sep 15).
He was speaking ahead of his presentation at Nanyang Polytechnic (NYP), which held a symposium on the effects of urban air quality on health. Dr Velasco also said that, aside from smoke haze, Singapore’s air quality is not as clean as it appears, and stressed the need for daily and hourly measures of air pollutants.
“We have over one million cars, the second largest refinery complex in the world, all ships coming from China to Europe … we have factories … we have construction. So we have many types of emission sources (and) we are exposed to those pollutants,” said Dr Velasco.
Currently, the National Environment Agency’s (NEA) website provides only real-time figures for PM2.5 and nitrogen oxide. Hourly average figures are provided for four other air pollutants: Carbon monoxide, sulphur dioxide, ozone and PM10.
TACKLING SOURCES OF POLLUTION
Elaborating further on particles produced during construction activity — one of the major sources of pollution — Dr Saji George, senior lecturer at NYP’s School of Chemical and Life Sciences, said people living on lower floors near construction sites are exposed to greater concentrations of particles, which pose health risks. Smaller particles can reach the deeper layers of the lung and even enter the bloodstream, he said, and with chronic exposure can lead to respiratory illnesses or even heart-related illnesses.
With the current haze levels, Dr Velasco also suggested taking stronger safety measures, starting with the closing of schools. This episode has seen PM2.5 levels ranging between 100 to 200 micrograms per cubic metre, even hitting a high of 341 micrograms per cubic metre on Monday night. This far exceeds the international standard of a 24-hour average of 25 micrograms per cubic metre, he observed, adding that in Mexico, factories sometimes have to shut down.
Dr Christopher Cummings, Assistant Professor of Strategic Communications at the Wee Kim Wee School of Communication and Information at Nanyang Technological University (NTU), noted that Singaporeans may be well educated, but are unlikely to delve into the science behind pollution to conclude if it is safe to be outside.
To that end, Dr Cummings, who is also a member of the Centre for Healthy and Sustainable Cities at NTU, said he and his colleague, Professor Theng Yin Leng, have been developing the prototype app known as HATS (Haze Analytic Tools). The app, which could be launched in a year or two, uses NEA data, the user’s personal health profile and location-based Pollution Standards Index levels to give the user real-time advisories.
“At the end of the day, we want the public to have the information they need to make an informed decision about how best to protect themselves,” said Dr Cummings.
As for tackling sources of pollution, Dr Velasco said reducing road traffic — a major source of pollution — investing in public transport and encouraging cycling and walking could help. He also suggested stricter regulations such as fuel restrictions for passing ships. “In Europe and the United States, it’s mandatory for the ships when they approach the coast to switch to burn clean fuels (which emit less sulphur dioxide),” he said, adding this should be implemented here.