The Straits Times reports that the Singapore Institute of International Affairs (SIIA) has launched a Clean City Air Coalition and aims to raise awareness on air pollution issues in Singapore and the region. While Singapore is not considered a highly polluted city, researchers agree that there is room for improvement.
Towards a robust clean air strategy
LAST week, the Singapore Institute of International Affairs (SIIA), a think tank, launched a Clean City Air Coalition to raise awareness of air pollution issues in the region and even within Singapore.
Our island-state has better air quality than many South-east Asian neighbours but it is still not up to World Health Organisation (WHO) standards.
Air pollutant levels here, while on a downward trend since 2005, were actually worse last year than in 2007, according to statistics released by the Ministry of the Environment and Water Resources last month.
Critics say there are gaps in both data and policy, and a lack of comprehensive air quality management.
Still, done right, there are opportunities for Singapore to lead in managing urban air pollution, they add.
Data issues can be sticky and the first hurdle is defining what is clean air exactly. The way WHO sees it, the goal is protecting human health so the levels of pollutants in air must be so low as to have a significant reduction in health risks.
Each year, some three million people around the world die prematurely from indoor and outdoor air pollution. Urban air pollution, such as black-carbon particles from transport systems, is a big culprit.
In Singapore, there have been a handful of studies on air pollution and human health – some linking haze to asthma and one showing that hawker centre workers have up to twice the normal risk of cancer from higher exposure to fine particles generated by cooking.
The next challenge is measuring the pollutants. While there are five key pollutants in Singapore’s Pollutant Standards Index (PSI) – sulphur dioxide, nitrogen dioxide, ozone, carbon monoxide and particulate matter – they are not the only villains.
The five are used as indicators as they are relatively easy to measure and correlated with a cocktail of other airborne toxics. For example, nitrogen dioxide emissions from vehicles tend to increase in tandem with benzene or particulate matter levels.
Not included in the PSI is a pollutant known as PM2.5 or particles smaller than 2.5 microns in size. Still, it is measured because the finer the particle, the more likely it is to penetrate the lungs and the more dangerous it is to human health.
Last year, the annual mean PM2.5 level here was 17 micrograms per cubic metre. The National Environment Agency (NEA) aims to cut that to 12 by 2020. The WHO standard is 10 micrograms per cubic metre.
Similarly, the local standards for sulphur dioxide, ozone and particulate matter do not meet the WHO ideals.
A second problem for policymakers is that efforts at clearing the air, while staving off climate change, can be at odds with each other.
At last week’s Clean Air Forum, organised by SIIA as part of the Clean Enviro Summit at Marina Bay Sands, National University of Singapore researcher Kua Harn Wei illustrated the contradiction with the example of catalytic converters which convert toxic chemicals from vehicle emissions into less toxic ones. These may reduce the amount of carbon monoxide belched out from tailpipes but they can also increase the amount of nitrous oxide, a greenhouse gas. So this measure aimed at cleaning up pollutants ends up feeding global warming.
SIIA director and Nominated Member of Parliament Nicholas Fang pointed out at the same forum that low-carbon diesel cuts carbon emissions but can spew particulate matter into the air, giving some people breathing problems.
Yet another example is the power plant being built on Jurong Island to burn low-sulphur, low-ash coal, palm shells and wood waste. The good news is that new technologies may keep ash and sulphur dioxide from being pumped into the air but the fact is that coal still generates more greenhouse gas emissions than natural gas.
It can seem as though climate change and air quality are managed completely in isolation from each other.
Scientists also point out that Singapore needs more detailed risk assessments, maps and models of air pollution.
In May, atmospheric scientists Matthias Roth of the National University of Singapore and Erik Velasco of the Singapore-MIT Alliance for Research and Technology published a paper pointing out gaps and identifying the opportunities in Singapore’s air pollution management.
The paper acknowledged: ‘Singapore is far from being a hazy and highly polluted city.’
But it also noted a gap. Singapore has specific air quality targets, and it has long trumpeted its general strategies for improving air quality, such as promoting public transport, improving energy efficiency or enhancing land use planning – yet there is no apparent technical analysis of how well these will work to reach the proposed targets.
It said: ‘A formal risk assessment… which evaluates the co-benefits for other pollutants of attaining these standards, is not apparent, nor is there an air quality management plan for addressing these goals.’
Dr Roth and Dr Velasco suggested more models and maps of how air pollutant levels vary in time and space, even as frequently as hourly or daily, and recommended studies into how multiple pollutants are formed, emitted and transported in Singapore’s tropical urban atmosphere. There could be more live maps and visualisations of air quality, such as Europe’s live ozone-pollution map. And there should be more specific, detailed inventories of emissions – to better protect those in high-risk micro-environments like hawker centres.
Plus, the researchers said, air quality management must take into account seasonal shifts in weather patterns, such as the annual south-west monsoon. For instance, more than half of sulphur dioxide emissions here come from refineries located in the south-west, either on the mainland or offshore. When the wind blows from that direction during the monsoon, residents in those areas could be affected.
It can’t be denied that Singapore’s efforts at air pollution management are evolving. Minister for the Environment and Water Resources Vivian Balakrishnan had told Parliament earlier this year that the NEA is reviewing PSI to include reports on the levels of PM2.5 on its website more frequently, although he did not say when that would start.
In another change, the NEA stipulated that from this month, newly imported non-road diesel engines, such as those in cranes, excavators, forklifts and diesel generators, must meet more stringent emissions standards.
There may be room, too, for private industry to get involved in managing air pollution. Last week, computing giant IBM signed a $13 million collaboration with the NEA, funded by both and the Economic Development Board, to develop better models of various environmental risks – including air quality.
The SIIA’s Clean City Air Coalition comprises parties involved in controlling air pollution, such as Senoko Energy, and those who could bear the brunt of failed efforts at controlling air pollution, such as the Sentosa Leisure Group.
Such firms have contributed about $100,000 in funding to the coalition, which aims to increase companies’ and the public’s understanding of what clean air really means and help shape regulatory policy.
If air quality measurements can be crowd-sourced, say by snapping geo-tagged pictures of smoky installations or with the sort of smartphone air quality sensors now being developed elsewhere, better air quality management need not be costly.
In fact, as Dr Roth and Dr Velasco pointed out, Singapore could be at the forefront of tropical air quality research and management. Combined with its strengths in water management and green building design, this would help seal the island-state’s reputation as a sustainable green city.
But first, let’s usher in a comprehensive air quality management strategy.
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