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Air Pollution vs. Allergies and Respiratory Illnesses

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Hong Kong’s increasingly polluted air could be to blame for more allergies and respiratory ills than we realise

Hazel Parry – Updated on Jun 30, 2008 – SCMP

It may start with a few sneezes and a runny nose, progress to a cough and then turn into a full-blown hacking wheeze. At first you may think you’re suffering from a chest infection brought on by a cold, but when the cough fails to show signs of abating two weeks later, you consult your doctor. The problem: Hong Kong’s bad air. You’re suffering an allergic reaction to pollution.

The smog that regularly cloaks our skyline is getting worse, and it’s not only annoying tourists who make the trip up Victoria Peak only to see nothing and driving businesses to other Asian cities, it is also interfering with the quality of life and the general health of people who work and live in the city.

A recent report by the think-tank Civic Exchange claimed poor air quality was responsible for 10,000 premature deaths and 440,000 hospital bed days a year in the Pearl River Delta, at a cost of 6.7 billion yuan (HK$7.6 billion) annually.

And it’s not just the very young, old or those with existing respiratory problems such as asthma who are paying the price for pollution. Ear, nose and throat experts claim they are seeing an increasing number of seemingly healthy people seeking help for problems of the upper respiratory system caused by pollutants in the air they breathe.

Some are suffering in silence – blaming their symptoms on colds, stress or being overtired, and letting the problem affect their life, sleep patterns and working day. They may be dangerously self-medicating or dosing themselves with cold remedies. Others are seeking help from their GPs, only to find there’s little they can do.

The Civic Exchange report claims pollution is behind 11 million doctor visits a year. A separate study by the Chinese University of Hong Kong published in 2005 found a significant link between people making first visits to their GPs with upper respiratory tract problems on days of increased pollution. This led the researchers to conclude that “air pollution, besides affecting at-risk populations [those with existing problems], also affects the relatively healthy population.”

The Chinese University study monitored more than 300,000 consultations from 13 participating GP surgeries across Hong Kong between 2000 and 2002 to assess the risk of less serious or short-term effects of pollution on health (as opposed to the serious effects, which require hospitalisation). Researchers say about three-quarters of the consultations were first visits for new health problems – and of those, two thirds were for respiratory disorders. They also found that as the concentration of pollutants such as ozone and nitrogen dioxide in the air increased, the greater the number of first-time visits there were for upper respiratory disorders.

“Although these illnesses are minor in nature with minimum long term effects on health, they represent a substantial proportion of overall morbidity in the community,” the study concludes, adding that the problems are a financial drain on Hong Kong in terms of escalating medical costs and loss of productivity.

According to ear, nose and throat (ENT) expert John Woo Kong-sang, in most cases an allergy to pollution manifests itself as rhinitis or rhino-sinusitis – inflammation of the mucous membrane lining of the nose or sinuses – causing symptoms such as runny noses, sneezing and coughing. A sore throat, phlegm, loss of smell, watery or itchy eyes are also common reactions to pollution.

Woo, an honorary clinical associate professor in the department of otorhinolaryngology at Chinese University, estimates that patients with allergic rhinitis or rhino-sinusitis account for about 30 to 40 per cent per cent of cases at the ENT clinic, up from about 10 to 15 per cent a decade ago.

“We don’t know for sure whether the increase is due to the growth in population in Sha Tin [the area the clinic serves], but judging from the number of people turning up at our clinics, I am quite sure the problem has become worse as pollution has grown worse, and it is affecting the health of the population in general,” he says.

Woo says the nose, as the air filter for the lungs, is the first to suffer from exposure to pollution. “When it’s working properly, the nose filters out about 90 per cent of pollutants. But when you have a lot of pollutants in the air, it has to work harder,” he says.

In people with allergic tendencies who have become sensitised to pollutants, a slight increase in pollution may be too much for the nose to bear, resulting in an allergic reaction – the inflammation and all the symptoms which come with it.

“You may think you have a cold and the symptoms may be the same. But the difference is that an infected condition, even without treatment, is self-limiting. It may last one or two weeks and then you get over it,” says Woo. “With allergic rhinitis, the symptoms will linger on.”

It’s the lingering nature of the symptoms that distinguishes an allergy from a cold, and which eventually leads many people to their GPs. Likewise, it’s the fact that symptoms occur year-round that makes many experts believe the problem is more likely to be pollution than pollen.

Respiratory specialist Lam Bing, an honorary assistant professor at the Faculty of Medicine at the University of Hong Kong, says rhinitis is known to affect about 20 to 30 per cent of the world’s population.

A recent report by the multi-centred International Study into Allergies and Asthma in Childhood claims that although cases of asthma appear to have reached a plateau, rhinitis is on the rise.

“I would say in Hong Kong the number of people with rhinitis is a similar number to the worldwide figure,” says Lam. “If you were to ask people a simple question such as, `Do you suffer from nasal discharge, blockage or congestion in the morning?’ you would probably find many people suffer some kind of complaint.”

“It’s a common problem, but many people ignore it. Especially as a typical feature of rhinitis is that the symptoms are worse in the morning but gradually improve during the day, so people tend to think they can cope with problem. If they have a sore throat they think it’s because they have talked too much or that it’s an infection.”

To what precise extent pollution is to blame for the growing number of minor respiratory problems is difficult to say because of the lack of research, says Lam, although studies have also shown that people living nearer highways have far more chance of developing respiratory problems than those living in urban areas.

Johnny Koo Tak-ching is in no doubt pollution is partly to blame for Hong Kong’s worsening coughs, sniffles, sneezes and sore throats. He’s an ENT expert at a private clinic in Central, the majority of whose patients are expatriates who move from city to city in their work.

“Those patients who have long-term rhinitis, sinusitis and nasal polyps get worse when they’re working in a city with higher pollution. They can tell which city has the worst pollution by how bad their symptoms get,” he says.

“They feel much better in places like the Mediterranean and some northern Chinese cities, such as Harbin, but feel worse when they move to places like Shanghai, Beijing and Hong Kong. Singapore is better than Hong Kong, and Kuala Lumpur is better than Singapore.”

The bad news for everyone living and working in central Hong Kong is that there’s little we can do while pollution remains a problem.

Antihistamines, which reduce allergic reactions, can alleviate itching and sneezing, steroid-based nasal drops can reduce some of the inflammation and clear the nose, and pain killers provide relief for a sore throat. But all of these treatments only address the symptoms and not the cause, and, in the long term, nasal allergies can lead to nasal polyps, which may require surgery.

Koo says: “Reduce your exposure to very polluted areas. If you know you’re going to a more polluted area, then start the preventive medicine for the allergy before you go. If you have minor symptoms such as throat discomfort or more phlegm, keep an eye on your health, drink more water and take some vitamin C, and you should be fine.

“However, if symptoms last more than a week, you had better see a doctor to see if there’s a more serious problem.

“Unfortunately, my impression is, generally, there is no escape – unless you move to another country that’s less polluted.”

Koo’s observation is reflected by the experience of Elaine Tse, who has suffered from a sore throat that has persisted for months despite the installation of a HK$12,000 air purifier in her home. “Nothing was working, so I went to the ENT specialist, who stuck a camera up my nose and down the back of my throat,” she says. “He asked me if I’d visited any toxic plants in China. I hadn’t, of course. He concluded that it was allergies to the pollution and gave me antihistamines.”

That conclusion was borne out when Elaine took a trip to Australia. “After just 24 hours the sore throat went away,” she says. “Now I am back in Hong Kong, it’s back again.”

One Comment

  1. Elsa Wong says:

    My husband is a German. He had lived on Lantau Island for over 20 years. Recent ten years, he developed bad air allergy. The illness linger on long time. We had consulted many doctor without improvement. Everytime when he goes back to Germany for a break, in two days, it is over. Can you give advise?

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