The impact of haze on our health is diverse as fine particles can bypass our normal immune systems and find their way into the lungs and other tissues via the bloodstream. The particles, in particularly PM2.5 (find particles) released by forest fires) can interact with other important substances in the body, such as LDL (Low Density Lipoproteins) to cause such symptoms as inflammation. The effect of the pollutants entering the lungs includes impaired pulmonary function, which in not limited to adults but also in infants. For example, in 1977 South East Asian haze, a seemingly small increase in air pollutants by 100μg/m3 has led to increases of 12% of upper respiratory tract illness, 19% asthma, and 26% nasal inflammation. In general, the effects can be classified into short-term and long-term effects.

Short-term adverse effects include eye irritation and headache.

Long-term adverse effects include respiratory and cardiovascular diseases. The exposure to fine particles can lead to a faster thickening of the arteries (atherosclerosis), which in effect leads to a high blood pressure. Research conducted by an organisation in the US has found that 10 μg/m3 increase of PM2.5 causes 1% increase in diabetes risk.

However, the extent to which haze impacts individual’s health depends several factors:

  • Health status, depending on how sensitive you are.
  • Elderly, children, and pregnant women are more vulnerable to experience health issues because they have a low immune system, whereby
  • PSI level and duration of exposure to haze
  • The amount of influence on health also depends on the severity of the haze. The table below shows the recommended amount of outdoor activity depending on the PSI level.






Haze like the trans-boundary haze in 2015 impacted Indonesia as well as countries in South East Asia (SEA) such as, Singapore, economically. These economic impacts are estimated as it is hard to exact the degree or significance of haze on a country’s economy. However, government of these countries confirmed that the haze did indeed impact economies of countries in the region.

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Children cover their noses near burnt land in Marpoyan Damai sub district, in the outskirts of Pekanbaru, in Indonesia’s Riau province June 20, 2013

Haze has led to many social impacts in Indonesia as well as countries in the South East Asian region.

Indonesia greatest impact has closest to the haze. Many homes of the vulnerable- young, elderly and pregnant – had to be relocated, causing inconvenience for them. Besides that, the education of school children were affected as many schools had to be close due to hazardous levels of haze. Businesses and schools across the region close due to the haze, crippling many low-income families and prompting them to fall back into poverty. Approximately 5 million students have been impacted by school closures in 2015.

Haze forced school closures for up to 34 days, resulting in USD 34 million in costs. 14 In some instances, schools closed for weeks at a time, obliging teachers to accommodate take-home assignments. Conditions were worst in October 2015, impacting 24,773 schools and 4,692,537 students. Child-care costs and foregone wages increase when parents must care for children normally in school. These long-term, sustained school closures could contribute to weaker graduation rates if reclaiming lost school days becomes burdensome.

I had personally experience haze during my school days in secondary school and junior college. The impact on which haze had on our school curriculum was harsh and classes had to be relocated to air-conditioned rooms and some classes like Physical Education (PE) even had to be cancelled. Both events were on the year of my major examinations – O’levels and A’levels and many students, including myself, were anxious if the haze would affect our sitting for the examination. Schools did not close despite the PSI hitting to a high of over 400 (hazardous) in 2015, however, schools were prepared in the case that closure of schools were to happen.

Hardware shop Home in Clementi put up a sign announcing that it was giving away free masks to the elderly and children. PHOTO: THOMAS CHIA

Despite all the negative impacts, it has brought about the “Singaporean spirit” and sense of community in Singapore as organisations and people give out free mask to fellow citizens. While there were reports of people cashing in by re-selling N95 masks at a higher price during the last haze crisis in 2013, one hardware shop is doing the exact opposite this time round.

Local kindness movement Stand Up For Singapore kick started a fund-raising campaign called “I Will Be Your Shelter” to buy air purifiers and filters for the elderly and needy in the North Bridge Road area. It raised about $6,000 through crowdfunding site Indiegogo and donations as of October 2015 and distributed 40 air filters and 10 purifiers to the residents on September 19.

There are many other kind acts by Singaporeans during the tough times of haze such as a mask-collection drive “Let’s Help Kalimantan” launched by sisters and a project “3,000 masks, 1 Singapore” by Mr Cai Yinzhou.

Forget The Maze Runner, in Singapore we have… Credits to M2CTR

The haze has also created a common topic for citizens to talk and joke about. Above is an example.
In conclusion, despite all the adverse impacts on society, there has been some positive light. However, this does not dampen the negative impacts of which haze has manifested.


Group Application Exercise 5

  1. How can you purify your water when you are hiking? Name two or three possibilities. Compare these methods in terms of cost and effectiveness. Are any of these methods similar to those used to purify municipal water supplies? Explain.

Mountain streams may look pristine and pure, however from a chemical standpoint it may not be safe to drink. Water obtained from natural sources may contain particulate matter, bacteria, viruses, microorganisms and unsafe chemicals.

Boiling water is probably the most simple and effective method to purify water, but not the most widely practiced method used by hikers. This is because it requires building a fire or using a stove. It also leaves the water unpleasantly warm for immediate drinking. Boiling also does not remove any particulate matter suspended in the water or chemical contamination.

In terms of cost, boiling is the cheapest if boiled using a fire. However a stove requires fuel which needs to be replenished. Hikers generally already bring along a stove to cook food, hence little extra cost is incurred and this is probably the cheapest method. 

Another method of purification is filtering. Water filters act by physically removing harmful content from the water. Water filters for backpacking typically have a pore size of 0.2-0.3 microns. This means that anything that is smaller than that will slip through the filter and end up in the drinking water. A pore size of 0.2-0.3 microns is small enough to remove microorganisms and bacteria. However, viruses are typically smaller than 0.1 micron and will not be removed.

Water filters on the market vary greatly in price, from as cheap as $30 to as much as $200, depending on the quality.  However filters generally have a usage life or capacity, after which it needs to be replaced.

Municipal water is water that delivered to taps such as in our homes. Boiling water when hiking is similar to how we boil water at home before consumption.

2. Explain why desalination techniques, despite proven technological effectiveness are not used more widely to produce potable drinking water. 

Since seawater is available in enormous quantities and readily accessible, it may seem intuitive to simply desalinate water to get potable water. However it is not a widely used method because of various challenges.

Firstly, desalination is an energy intensive process that requires sophisticated equipment. Hence, it is a costly process compared to other alternative methods of getting potable water, such is importing water from other places with existing potable water sources. Hence as long as less expensive options are available and capable of meeting demand, it is usually not used.

Also, desalination is done through reverse osmosis which uses pressure to force salty water through a semi-permeable membrane that keeps the salt on one side and allows pure water to pass through to the other side. This process creates a salty brine byproduct that must be safely managed to protect the environment. The brine remaining after drinking water production must be disposed of by deep well injection or by diluting the brine before returning it to the environment. Otherwise, the increased salinity can cause significant damage to marine life and plants that are adapted to lower salinity. As such, environmental concerns stops desalination from being a more widely used method.

Another consideration is the quantity of water than can be produced. For example, Singapore’s TuasSpring Desalination Plant is one of the region’s largest seawater reverse-osmosis plants only meets 15% of Singapore’s water needs. 

3. Water quality in a chemical engineering building on campus was continuously monitored because testing indicated water from drinking fountains in the building had dissolved lead levels above those established by NEA. 

a. What is the likely major source of the lead in the drinking water?

The primary source for lead is most likely from the corrosion of piping used within the distribution system of water.

b. Do the research activities carried out in this chemistry building account for the elevated lead levels found in the drinking water? Explain. 

It is unlikely that the research activities are responsible for the elevated lead levels. There are usually strict guidelines and rules for chemistry labs regarding the disposal of chemicals. Harmful chemicals should never be disposed down the drain are usually disposed appropriately. For example, some waste must be professionally incinerated or deposited in designated landfills, while other waste are neutralised before discharge.


4. Some vitamins are water-soluble, whereas others are fat-soluble. Would you expect either or both to be polar compounds? Explain. 

Vitamins are classified as either fat soluble (vitamins A, D, E and K) or water soluble (vitamins B and C). The difference between them determines how each vitamin acts within the body.

Since “like dissolves like” the water soluble vitamins need to have similar polarity properties as water to dissolve. Since water molecules are polar due to the large difference in electronegativity between hydrogen and oxygen, it is a polar molecule. Hence water soluble vitamins have to be polar like water so that they can dissolve in water.

Whereas fatty acids generally consists of long carbon chains which are non-polar. Hence, fat-soluble vitamins  are predominantly non-polar and so that they can dissolve in fatty tissues in the body.