Dr Richard over at MyHealthBeijing has a couple of recent posts pertinent to families in Beijing:
The first includes a look back at an article Will Chickering wrote about indoor air pollution for Beijing Kids’ (now defunct) sister magazine Urbane and subsequently posted on Beijingcafe. "Basically, I learned that the worst component of air pollution from the point of health effects is traffic-related, i.e., within 150-200m of four-lane streets/highways (which can be easily identified on a Google Map of Beijing), and that the worst of the worst are fine and ultra-fine particles, which seep indoors with such efficiency that their concentration is almost the same indoors as out. HEPA air purifiers can help, but only in closed rooms where the machines need to be set at a rate to clean a room’s volume TWICE in one hour (to keep ahead of the seepage). Unless the rooms are very small, this rate is very loud." Read more here.