Air Pollution

When Australians travel overseas, they will usually experience air quality worse than they are used to at home.  It has been known since the industrial revolution that extreme air pollution can cause acute symptoms, chronic heart and lung diseases, hospitalizations and premature death.

Those most at risk are the very young, the elderly and those with heart and lung conditions, including asthma. Some forward planning is a good idea. If you have a respiratory condition, why choose Beijing in winter when you could see it briefly in spring then travel to more rural parts of China?   Why accept a position in a highly polluted city if you have asthma and there is an alternative option?

There is no global consistency in the way air quality is measured and reported.  Air pollution is made up of particulate matter (reported at either PM 2.5 or PM10 micron diameter micrograms per cubic metre and gases - ozone (O3), sulfur dioxide (SO2), carbon monoxide (CO) and nitrogen dioxide (NO2). Large particles are trapped by nasal hairs and mucous membranes. Particles under 3-micron diameter are “respirable” or “breathable” and are thought to have the worst health impact as they can reach the lung tissue itself. Emissions are not the only causal factor. Wind and rain can clear the air of a city while a dust storm from the desert or construction sites can foul it.

The WHO uses an annual mean urban PM 10 as an indicator of outdoor pollution. This can range from 11 (Australia is 13-18) to over 200. Standout worst countries are Mongolia, Botswana, Pakistan, Senegal, Saudi Arabia, Egypt, Bosnia-Herzegovina, India, Iran, Nepal and China. Standout bad cities are Gaborone, Beijing, Chengdu, Urumqi, Cairo, Agra, Delhi, and Ulaanbaatar.

For real time country information Refer to AQICN

If you have no access to the internet, then you will have to use visibility as an index. This is particularly important for those at risk of serious health complications.

Many large cities have a method of alerting their residents to the local version of an Air Quality Index.

(AQI) The Seoul Tower shines blue on days of good air quality, encouraging citizens to get their outdoor exercise that day.  Such indices are determined by parameters that change hourly.

Expatriates in Beijing refer to iphone.bjair.info for an instant PM2.5 reading from the US Embassy.  Good is less than 50, over 200 is mask time and 300 is the cut off for outdoor activity. A really bad day can nudge 1000!  There is no point averaging the numbers when an annual tally of really bad days is more useful.  You will know it is a really bad day when the temperature is minus 5 degrees, it is windless, and the coal fired heaters and industries are belching.  You will be coughing, with eye and throat irritation, headaches, nausea, wheezing and phlegm.  It will be twice as bad as hanging out in the airport smoker's lounge!

Any pre-existing lung problem could become worse than you've ever experienced. That's why you should have prepared ahead with your step-up asthma plan just in case. Asthmatics should imagine they may get a “worst ever” attack and pack a short emergency course of oral prednisolone tablets, just in case.  "Beijing cough" is just as likely in many cities of South Asia and the Middle East.

Poor air quality is not only a problem of industrialized, urban environments. Your eyes, nose, throat and lungs can feel just the same in a village hut from in-door solid fuel smoke or from the famous Harmattan winds of West Africa as in Beijing on a bad day.

It really is worth checking out the environmental hazards in advance of your trip.

On extreme days you might:

• Watch what the locals are doing
• Avoid strenuous outdoor exercise
• Get out of the city
• Work from home
• Wear a mask

All masks are not created equal. “N95” means that a mask has been tested and certified to filter out at least 95% of challenged airborne oil free particles > 0.3-micron size by the US NIOSH agency. Many “3M” cheap and readily available disposable masks have this certification. Many other brands would be equivalent but may be labelled with the European Standard (EN149FFP2) or the Chinese Standard (YY0469). By comparison, the cloth face mask/warmers seen commonly on the streets of China in winter would, when tested, have about an N28 rating if tested for PM filtration. There would be nothing to stop you wearing one over an N95 to blend in.

Long-term residents may prefer to invest in a more stylish and durable face mask. A mask may rate well in terms of lab tested material filtration and it will be marketed on this basis in the manufacturer’s website. Real world effectiveness is, how-ever, reduced by poor seal and fit. Not all brands provide childrens’ sizes.

N95 masks do not filter out the gas component of air pollution unless they are fitted with special disposable carbon filters. Masks with an expiration valve are much more comfortable to use with improved airflow and less fogging if you wear glasses. (Sick people should use masks with-out expiration valves to prevent germ spread).

Well-fitted N95 masks do work. The following is a testimonial from a volunteer in Ulaanbaatar, Mongolia.

“My mask is absolutely indispensable! The days on which I haven't worn it, I have immediately begun suffering from throat irritation and coughing.”