Air pollutants can trigger underlying health conditions and affect the body in numerous ways. LEE HUI CHIEH reports
After the haze hit Singapore in 1994, Ms Edna Chia was diagnosed with asthma – at the age of 47. She recalled: “I didn’t have asthma in my childhood. I had not even heard of it.” It started with a cough, which persisted for months, and worsened into wheezing and breathing difficulties. When she was finally diagnosed with asthma, she was
in hospital for about 10 days. She now takes medication daily.
Ms Chia, now 63, a sales executive at a piano shop, said: “This is old-age asthma that I have to take to the grave.” Though it is unlikely that the haze caused her asthma, it probably triggered a latent genetic predisposition, said her doctor, Dr Chan Tiong Beng, a consultant respiratory physician at Mount Elizabeth Medical Centre.
This is the hidden danger for such people from haze – a mixture of suspended particles, water vapour, carbon dioxide, carbon monoxide, nitrogen oxides and other chemicals. Though intermittent haze in Singapore is unlikely to be hazardous to healthy people, it can aggravate underlying conditions. Last week, smoke drifting here from burning forests in Indonesia pushed air quality to over 100 points on the Pollutant Standards Index (PSI), signalling unhealthy air.
So how does haze hurt the body?
During inhalation, particles and chemicals irritate the nose, which secretes mucus to flush out the particles. As more mucus is produced, the nasal passage becomes blocked and the nose swells. The reaction is magnified in
people who have allergic rhinitis, said Dr Kenny Pang, a consultant ear, nose and throat surgeon who runs a clinic at the Paragon. If the symptoms become too severe, they can take antihistamines, he said.
Airways and lungs
The particles may inflame the airways and the lungs as they travel downwards. The airways and lungs produce phlegm to try to get rid of the particles. The airways spasm to provoke a cough to expel the foreign matter. As phlegm narrows the
airways, more phlegm is produced, creating a vicious circle, said Dr Chan. Even people without chronic respiratory problems can suffer from breathlessness, he said.
Children are more vulnerable as they breathe faster, have a higher metabolic rate and have lungs that are still developing, said Dr Ong Thun How, a consultant at Singapore General Hospital’s respiratory and critical care medicine department.
The elderly and pregnant women should also take extra care, because their lungs tend to have less capacity, he said. Worst-hit are those with asthma and chronic lung conditions such as chronic obstructive pulmonary disease. They should keep to their daily control medication and increase the dose, if needed, according to an action plan drawn up earlier with their doctors, said Dr Gerald Chua, head of the department of medicine at the Jurong Health Services-run Alexandra Hospital. They should make sure they have an adequate supply of rescue medication in case of an attack, he said.
With the nose and airways inflamed, the body is under stress and the heart pumps faster, increasing the blood pressure. The body also releases chemicals that make blood clot more easily. Higher blood pressure and the formation of blood clots can cause a heart attack, stroke or heart failure in those who have coronary heart disease or whose hearts are already beginning to fail, said Dr Chuang Hsuan-Hung, a cardiologist from Gleneagles Medical Centre.
The particles and chemicals can cause burning sensations, irritate the eye into tearing to clean itself and inflame the
conjunctiva, the surface layer on the white of the eyeball. Those with a history of dry, sensitive eyes and allergic conjunctivitis are most at risk, said Associate Professor Chee Soon Phaik, who heads Singapore National Eye Centre’s ocular inflammation and immunology service and cataract service.
The inflammation of the conjunctiva worsens dry eyes and adds to existing inflammation from allergic conjunctivitis, she said. Avoid wearing contact lenses and put on wrap-around glasses. Use preservative-free lubricants every hour to remove allergens. Any eye swelling can be reduced by placing a warm towel over the eyes for a minute or two. If the symptoms worsen or become severe, see an ophthalmologist, who may prescribe medications such as
The haze should have little effect on healthy skin, said Dr Steven Thng, consultant dermatologist at the National
Skin Centre. But those with eczema – “asthma of the skin” – may find it becoming itchy and inflamed, he said. Using moisturiser three to four times a day can help protect the skin.
People with chronic diseases, especially serious ones such as heart and lung diseases, should stay indoors and avoid physical activity outdoors when the PSI hits about 80, doctors advised. Healthy people should do so when the PSI exceeds 100 and crosses into the unhealthy range, they said. If they have to go out, they may wish to wear surgical masks, but these may not block fine particles which can still wreak havoc on the body.
Ms Chia is on her guard against the potential health threat from the current haze. She has increased the dosage of her daily control medication and will stock up on her rescue medication soon. She said of her asthma: “It has happened, so you just have to learn how to live with it.”