A serious problem
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.
With the Olympic restrictions ended, air pollution has resumed its grip on the capital. And of course, other cities never had an air quality holiday. Effects on infant mortality and child development are well-documented, which means that when you return home with your new child, you’ll want your physician to pay special attention to lung function and toxic metals.
The Four Furnaces
A term used by the Chinese to describe the heavily industrial, heavily polluted, and in summer, incredibly hot centers of economic activity:

Note the proximity of these factory towns to the most-common places where our adoptive children come from.
Indoor Air Quality
Let’s not forget how common smoking is and what it does. A recent survey calculated almost 2/3 of adult males have the habit.
Smoking is banned on aircraft, but in public settings such as restaurants, offices, and lobbies, prepare yourself to encounter widespread tobacco use.

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.
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.
Your guides will have booked you onto the “Western” floor of your hotel, 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.
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 child have one last strategy the local residents don’t: leaving for cleaner air. In two weeks or less, you’ll be home.