The haze is a perennial problem in Singapore and its regional neighbours. While there may be several causes as to why the haze has occured in Singapore for the last few years, the most common reason is due to the burning of plantations in Indonesia, when farmers clear the land.

However, in the last week in Singapore, there has been some occasional unidentified haze in Singapore. This could be due to regional forest and peat fires, but not originating from Indonesia.

So the haze problem may be with us for a while.

I talked to a medical doctor, Dr Ooi Wei Seong, about the effects of the haze on people.

According to him, the haze is much more than an annoying smell for active individuals. It can also pose health risks according to Dr Ooi, 41, Consultant Medical Oncologist at the Harley Street Heart and Cancer Centre.

He said, “The haze particles, when breathed in, induce inflammation in the airways and this leads to a lot of sensitivity, causing breathing problems in some people. In others there will be an increase in phlegm production which leads to more coughing.”

Exercise during haze causes both short and long term problems

And exercising in the haze can cause both short and long term problems, according to the oncologist.

Said Dr Ooi, “In the short term, prolonged exercise during hazy spells will affect the more sensitive population such as asthmatics and people with chronic lung problems. It also irritates the eyes, nose and throat so you may get excessive tearing or a sore throat after running.”

He added, “The longer term affects would be the possibility that it may increase lung cancer risk and heart problems. This is more attributed to the small particles in the haze.”

These negative side effects are especially so, for cancer patients. Said Dr Ooi, “Anything above PSI of 100, I would advise staying indoors. This will lessen the irritation to the different body systems, particularly when cancer patients are already vulnerable while undergoing treatment.”

Studies have proven a link between air pollution and lung cancer

Enough studies have proven there to be a direct link between bad air and lung cancer, according to Dr Ooi.

He said, “The World Health Organisation has classified air pollution as a cause of lung cancer. Some of the population studies have shown that in certain countries with increasing pollution such as China, the incidence of lung cancers is increasing.”

Continued the doctor, “The reason is that the pollutants in the haze produce change in the cells of our body, leading to cancer. This could only be demonstrated in animal studies though, as it is impossible to do a similar study in human beings. But at the same time, it also depends on a person’s risk factors such as genetic susceptibility, smoking habits and exposure to second-hand smoke though.”

Guidelines on when it is safe to work out

As such, it is due to these dangers, that the National Environmental Agency (NEA) in Singapore has guidelines on what is a safe range and still okay to work out, and when it is recommended to stay indoors.

Added Dr Ooi, “There are guidelines on a ‘safe’ range for exercising. To me, if I can smell it, I won’t feel comfortable exercising anyway. But I find that generally up to 70 to 90 is still ok for most people. I do caution people to check the normal range properly depending on what PSI website they go to, in any case.”

And those who may think that they can beat the haze by wearing N95 masks to work out, may not be doing the right thing, according to the oncologist.

He said, “The N95 masks are ok for walking. But if one has to breathe really hard when wearing the mask, this can pose additional strain on a person particularly when the exercise is strenuous. In addition, often during exercise, the mask may move or the face may distort, leading to leakage which will defeat the reason for wearing the mask in the first place.”

Haze Advice by Marathoner Dr Derek Li

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