Noise pollution in Singapore: When buzz becomes noise

Increasing density, more traffic part of reasons for complaints about noise
Goh Chin Lian, Straits Times 30 Nov 10;

THE chorus of complaints over noise levels has got - well, louder, in recent years. In fact, a veritable hullabaloo broke out when The Straits Times ran a story two weeks ago on government plans to reduce traffic noise. More than a dozen readers wrote in to complain about the din around their homes.

Some blamed their noisy homes on MRT trains or vehicles on expressways.

Mr Philip Goh, who lives in Pasir Ris, fingers buses and lorries rushing by as late as 1.30am and as early as 5.30am. Mr Nick Low was irate at illegally souped-up cars and motorcycles racing past his Ang Mo Kio home in the wee hours.

Noise at construction sites and entertainment outlets is another frequent source of complaints raised by residents, as well as MPs in Parliament.

A measure of how upset people have been: Last year, the National Environment Agency (NEA) received 12,000 complaints on construction noise. That's down 12 per cent from the previous year, but still double the figure in 2006.

Noise levels are set to rise as land-scarce Singapore becomes more built-up and vehicular traffic increases, if nothing is done now.

Already 7,022 people shared a square kilometre of land here last year, up from 5,900 a decade ago. The influx of immigrants and foreign workers has pushed population past the five-million mark.

Vehicle population, at 942,861 last month, is also up by a third from 692,807 at the end of 2000. The growth has slowed from 3 per cent a year in 2008 to 1.5 per cent since last year.

Noise adds buzz to a city, but too much of it is hazardous to public health. Research overseas has found that a constant noise level of more than 80 decibels has been associated with increased risk of permanent hearing loss, 65 decibels with hypertension and heart disease, 55 decibels with significantly disrupted sleep and 40 decibels with reduced concentration. Traffic noise can reach 80 to 85 decibels. More local research is needed, as people's thresholds for noise tolerance could vary.

Singapore is a fairly noisy city. Ambient noise in Singapore measured in the quiet of the night is at least 55 decibels, compared with 40 to 50 decibels in Europe, NEA officials said.

Can nothing be done to keep down the noise in a fast-growing, fast-paced city?

Actually, quite a lot is being done.

For a start, guidelines limiting noise emissions are becoming more stringent.

Take construction sites. Noise limits of sites near residential areas were tightened in 2007, from 60 to 90 decibels averaged over five minutes, to 55 to 75 decibels. The maximum fine for violations was doubled from $20,000 to $40,000.

From Sept 1 this year, new sites within 150m of homes can no longer carry out construction from 10pm before a Sunday or public holiday to 10am on the day itself. Come Sept 1 next year, the prohibition will be extended to the whole of Sundays and public holidays.

Or take vehicle exhaust controls. Caps on noise emission by new vehicles were reduced by 3 to 8 per cent last month, from 99 to 107 decibels, to 94 to 100 decibels. Existing vehicles face a cut from April 1 next year, from 105 to 115 decibels, to 99 to 107 decibels.

A longstanding rule limits noise for MRT lines: No more than 67 decibels over a one-hour period measured at the facade of the block of flats. The authorities said in a 1995 circular that this level is achievable with a 35m buffer for a block facing MRT tracks.

In recent years, the 67 decibel limit is also applied to new roads and expressways. But when widening an older expressway, engineers need to ensure only that the new roadworks do not cause an increase in the existing noise level, which could exceed the 67 decibel limit.

But the real question is whether these noise limits are appropriate for a city with growing population density, with HDB flats built closer to one another and to amenities like MRT lines and roads. And how do they compare to international noise limits?

To find answers to these and other questions, the authorities are hiring a consultant to study traffic noise from expressways, major roads and MRT lines, and to recommend noise reduction measures. The study is managed by an inter-agency working group, co-chaired by the Land Transport Authority (LTA) and NEA, and involving the HDB, National Parks Board, Urban Redevelopment Authority and train operator SMRT.

One priority area is to shield Singapore's many high-rise flats from ubiquitous traffic and other urban noise.

Already, some Singaporeans have their own ideas. One suggested replacing HDB windows with double-glazed ones like those in developed countries. The windows, made of two layers of glass separated by a vacuum and the perimeter sealed with rubber, are said to halve noise level, bringing the din of traffic here to a soothing 35 decibels. A three-panel window costs about $1,800, compared with $800 for normal windows. But to be effective, the windows must be kept shut, which means turning on the air-conditioner.

Another reader noted that waste collection trucks in Madrid run more quietly on compressed natural gas (CNG). Sembcorp is also testing a CNG truck, the Econic by Mercedes-Benz, which is said to cut noise by as much as half that of a truck running on diesel.

While the relevant agencies review existing guidelines and look at ways to reduce the noise imprint, there is one area where immediate action can be taken: Crack down on those noise-splitting engines of illegally modified cars and motorcycles.

Residents in estates from Sengkang to Tampines and Sin Ming, cite this as a top noise nuisance. Last year, the LTA took action against 2,510 motorists for illegally modified cars, 44 per cent more than in 2008. Another 310 summonses went to those who illegally modified their motorbikes. But residents say it's a cat- and-mouse game and illegal racers pop up late into the night.

The LTA and Traffic Police can start a campaign against such noise pollution and rope in residents to report such activity. A resident woken up from his sound slumber by a racing car or bike is very likely to cooperate and report a noisy transgression.