Chinese health dilemma: to open your windows or not

Almost every habitant in China, especially in big cities, has to face the Chinese health dilemma:

You have to close your house windows to shield the hazardous smog; on the other hand, you have to open your house windows for more fresh air to prevent Bird Flu (H7N9 virus). Which would you choose if you were in China?

So, it is understandable that increasing foreigners want to flee Beijing reported by Financial Times.