A serious problem for your trip to China
Beijing proved it could deliver clean air in time for the Olympics, but at an unaffordable cost - shutting down all industry and construction over several provinces, plus cutting private auto travel down to nearly zero. Since 2008, the central government has used similar tactics for delivering "blue sky days" around critical cultural and political events, and added a few more tricks like cloud-seeding, and some longer-term strategies like building up renewable power and moving "smokestack" industries further out into the countryside, but on the whole, northern and central China have only become more smoggy, more of the year, every year since then, as it keeps burning more coal and putting more automobiles on its highways.
After each "blue sky" event, air pollution resumes its grip on the capital. And of course, other cities never get air quality holidays. Effects on infant mortality and child development are well-documented, so if your trip to China is for the purpose of adoption, when you return home with your new child, you’ll want your physician to pay special attention to lung function and toxic metals. If your trip is more for culture or recreation, smoggy days can be a depressing and painful roadblock.
Japan, Korea, and Taiwan also have some smoggy days, but much less frequently than in the PRC - and when they do, it is often because winds have blown pollutants over from the mainland.
Indoor Air Quality
Let’s not forget how common smoking is and what it does. A recent survey calculated almost 2/3 of adult Chinese males have the habit.
Smoking is banned on aircraft, and is increasingly being banned in confined public spaces (at least on paper), but in settings such as restaurants, offices, and lobbies, prepare yourself to encounter widespread tobacco use - whether blatantly in the open, or surreptitiously in bathroom stalls and stairwells.
How to deal with it
First, we assume you’ve had a recent medical exam and have been found generally healthy enough to travel and exert yourself. (We’ve seen what has happened to someone with asthma, and it’s not pleasant.)
Second, and this should go without saying: stop smoking. Give yourself at least a fighting chance.
Third, get timely information about your destinations' pollution levels - both from news reports as well as smartphone apps that update AQI (air quality index) levels in real-time. If you're using a smartphone in China, make sure you can access your app in that country.
The body has a natural response: phlegm. If you’re under heavy smog for several days, you’ll start clogging up. Best not to fight it with decongestants; your immune system is trying to look out for you. This is why you’ll see so many people spitting and performing the “farmer blow”. Prepare yourself with an extra pack or two of your favorite brand of tissues, and keep some in your pocket when you can see the air.
Most of your hotels won’t allow you to open the windows more than a crack. We’ll save the discussions of the quality of building materials and why windows don’t have screens for later. The big reason is to keep out the dust - both from sandstorms as well as from construction sites and automobile exhaust. So keep those windows closed unless it’s pleasant outside.
If on a tour and staying at a Chinese-brand hotel, your guides will have booked you onto the “Western” floor, and often these are the no-smoking floors. If that isn’t the case, talk with your agency’s guide and get your room changed. At Western-branded and managed hotels, your expectations for air quality and smoking policies should be no different from at home. Newer hotels (mid-2000s onward) in major cities - especially skyscrapers - should have central HVAC systems that will help in filtering contamination from the outside air. (Older hotels are more likely to have each room served by its own unit, and thus a potential "hole in the wall" to your room.)
Finally, during poor air quality episodes, restrict your outside activity if you have any kind of sensitivity. Skip the guided tour, especially if it will be mostly outdoors. Pick up one of the “surgical masks” at the convenience store or market on your block - the locals will be using them, so no need to feel embarrassed. You should also bring a kerchief or large fabric square with you - again, while you may feel like you’re playing a Wild West outlaw, no one will criticize you for using it.
You and your children have one last strategy the local residents don’t: leaving for cleaner air. In a handful of days, you’ll be home.