top of page
Search
David L

Pollution in our Neighbourhood

Our Garden City - Singapore

Most people will say Singapore is doing pretty well on pollution. We rank 126th out of 142 countries in terms of carbon dioxide emission per dollar gross domestic product (International Energy Agency). That is 0.11 percent of global emissions (NCSS).


Other people might disagree. Singapore is 724 km square, consisting only 0.00000548% of global land area. They argue we are efficient, in carbon emitting - 20055x the efficiency of the average emission per unit land area. Compared to many other cities, we are very likely to be working fine. Only two countries globally are reportedly carbon-neutral (or negative): Bhutan and Suriname (wiki).


On a non-hazy day, Singapore scores well for all forms of pollution except noise and light pollution. Let's have a look on surveyed results on what Singaporeans think of our pollution level (numbeo.com).


In reality, we see small signs of pollution around our beloved dot. The 5 main categories of pollution include air, water, noise, light, and soil pollution. There are other environmental hazards like habitat destruction, nuclear pollution and even thermal pollution. Let's take a walk around my neighbourhood, not too far because of the circuit breaker, to see which types of pollution are out there.



Air Pollution

The avenue along where I live teems with vehicles. In Singapore, it is mandatory to have catalytic converters in vehicles (thankfully) and the government has implemented the certificate of entitlement (COE) bidding since November 1995 to manage the number of cars on the road. Nonetheless, vehicle exhaust still adds to soot, greenhouse gases, carbon monoxide and so on.


In the dental clinic I go to, nitrous oxide is provided to help anxious children. Nitrous oxide (NO) is a trace gas that occurs naturally, and its greenhouse effect is equivalent to 350 times of carbon dioxide! The dental output of this gas is negligible. Over 90% of the global nitrous oxide pollution in our atmosphere is a result of nitrogen-containing fertiliser in agriculture, something which we do not have in the neighbourhood.


Our country's major source of air pollution is still largely industrial based. This includes the seasonal haze from neighbouring forest fires, causing rises in PM2.5 (see below). WHO reports that around 7 million people died in 2012 from exposure to poor air quality (WHO). Logging and rapid deforestation of green spaces is not new to the history books. For example, Japan in the Tokugawa period (1500s) has faced rapid deforestation across the whole country. Japanese aesthetic culture favours the use of wood in houses, temples and major architectures. On recognition of this, the shogun implemented aggressive reforestation, and drastic measures in controlling wood consumption (such as reduce and reuse). In the present day, over 75% of Japan is covered in green spaces, including areas of reforestation (Jared Diamond, Collapse). Outside its cities, air quality is very good.

(Air quality today - from NEA.GOV.SG)



Water Pollution


The major waterbody in my neighbourhood is the Bishan park portion of the Kallang river. Prior to the re-bioengineering project in 2008, it was a large 'longkang' (see below).

Photo credits: C40


With the current natural vegetation along the river, such as the arrowheads and Thalia geniculata, various rock and stones - they act as a filter, picking up debris to improve water quality downstream. In the ongoing construction of Thomson-East Coast MRT Line, we can see sedimentation and some oil layer. However shortly downstream, the flowing water is clear and the tilapias and catfishes look reasonably satisfied. I think there was great insight by PUB and NParks to 'reforest' our waterbodies. We often forget the propensity of nature to heal.


Soil Pollution

Conventionally, soil pollution is thought to be improper waste disposal (lower left picture). With rigorous effort from our National Environmental Agency (NEA), our neighbourhood is largely litter-free. Soil erosion, is however not as simple as errant waste disposal. It is also now recognised that erosion of top soil (right picture), soil acidification (upper left picture), and degradation of soil quality are also manifestations of soil pollution.

Soil quality consists not just of the composition of the soil layers, but also a healthy community of microorganisms, flora and fauna. Soil movement can leave top soil exposed to sun, rain, wind and trampling. Leaching of chemicals like nitrogen fertilisers can increase acidity of the soil. Sometimes, rain water can drain the ash remnants into the soil (upper left picture), which lowers the soil pH also. In confined areas, these chemicals are unable to leach away effectively. Stepping onto the grassy areas also "pack" the soil tightly and kill off the grass. With the grass gone, it changes the biological community of the soil therefore.


Noise Pollution

In the poll for pollution in Singapore (numbeo.com), noise and light pollution constitute "moderate levels" of pollution.


The NEA recommends no more than 67 decibels averaged over an hour. The average outdoor sound level in Singapore averages at 69.4 decibels (Straits Times). However in sound samples taken in parts of Singapore, 27% of them are above 70 decibels. According to WHO, sound levels of above 70 decibels may potentially be damaging to living organisms, regardless of how long or consistent the exposure is.


In my neighbourhood, vehicles and construction are the main sources of noise pollution in the day. Even in wee hours, night "racers" electrify the restful ambience with thunderous roar of their engines and blasting "techno", just along that innocent avenue beside Bishan Park. Why do people stay up past their bedtimes? This brings us into the 5th major type of pollution.


Noise Pollution

Light orchestrates our biological circadian rhythm for sleep. Blue light, particularly from LEDs and screens, affects the production of melatonin, the sleep driving hormone. This affects our sleepiness, which supposedly peaks at 2-4am. Insomnia (an inability for restful sleep) is a common sleep disorder in Singapore, with a prevalence of 15.3% (SGH). Excessive ambient blue light at night could have contributed to this. This also includes school work using the laptop and handphones.


A few months back, I was at Singapore Science Centre's observatory to view the stars. When light pollution is reduced, I could see more stars with my naked eye than I imagined possible. I can even see the Orion's nebula! With light pollution, even the brightest star in the sky (Sirius) appears lacklustre. In the picture below, the white clouds reflect the city's light. We may not be able to see much of Sirius in this photo as a result.



In the early city planning of Singapore, lighting up the streets was suggested to curb gang activities and crime prevention. Various research do report that street lighting could reduce crimes by up to 20% (Farrington and Welsh, 2002). In addition to crime prevention, night-industries like transport, tourism, and food industries thrive with more light.


Do YOU think we have too much light and noise?


Other Types of Pollution - Habitat Destruction

It is a blessing to be a fit species. You are able out compete other species, establish your territory, reproduce and survive. Simple. Or is that not so simple?


Our last wild tiger was claimed in 1920s, while the last elephant succumbed earlier in 1900s. (You can still see tigers and elephant in our Singapore Zoo) During then, these large mammals are killed to protect gambier plantations and livestocks, and probably some of them were suspected murderers, and even possible ego-boosters. The clash between large animals and humans was inevitable as our ancestors settled in. A stark reminder that we were the invasive species displacing the natives.

Photo Credits: BiblioAsia


Today, we have settled well into our red dot. 56% of our land is "vegetation", 27% is actively managed (parks, gardens, lawns etc.) and primary forest or freshwater swap forest coveres only 0.28% of land area - confined to Bukit Timah and the Central Catchment Nature Reserves. The rest are unmanaged spontaneous vegetation, which would consist military areas (NParks).


Finishing our walk around my neighbourhood, I heard a scream and I hurried to find out what had happened. An auntie walking along the Old Upper Thomson Road has encountered a snake! It was a beautiful adult red-tailed racer (see picture below - centre). I dropped a few pebbles, and as our neighbourly snake sensed the ground vibrations, obediently slithered back into the lalang. Lest it gets run over by a vehicle on its "exploration", I thought.

Wild boar and macaque encounters are more common than snakes. Their natural predator the tiger has been out of the equation for a century now. As we see them, one might wonder about their fate, and ultimately our own fate.


In Jared Diamond's book named "Collapse", Easter Island was colonised by humans in 1200 (although it could be as early as 400AD). When Captain James Cook explored the island in 1774, there were only a few inhabitants with largely cleared lands. Through these 500 years, the inhabitants grew in size, established an "empire", built large stone monuments, exhausted food, faced decline, possibly even resorted to cannibalism. According to Mr Diamond, this was a "clearest example of a society that destroyed itself by overexploiting its own resources".


Singapore relies on import, which spares us from a similar fate. For now. We have to keep in mind that, other than all the islands on planet Earth, there will be no more island beyond. Although it is great to be super-survivors and super-competitive, is that always a blessing?


References:


This is a Young Environmentalist project

19 views0 comments

Recent Posts

See All

Comments


Post: Blog2_Post
bottom of page