Pollution is a problem in China, there’s no denying.  For the traveler, the main concern is air pollution inside the cities or around industrial areas.  So if you’re asthmatic or have some respiratory issues, this could be a concern. It’s possible that I’m not as sensitive to it because, personally, I’ve never really noticed it to be any worse than the pollution of say, L.A. or any other major Asian city.  Which is not to say that parts of China don’t have apocalyptic pollutions — but for the most part, these areas don’t overlap with the tourist destinations that you’ll likely encounter (such as mining towns and industrial centers). As far as getting sick from drinking water, bottled water is cheap and plentiful.  And because the Chinese love their tea, you’ll find purified, boiled water everywhere — from your hotel room to your train carriage. And in my opinion (and from talking with many travelers) your risk of getting food poisoning in China is low, especially compared to other developing countries.  Chinese food is typically made with fresh ingredients and stir-fried at high temperatures.  But still, be wary of any food that looks like it may have been leftover from yesterday’s buffet or otherwise sitting around.  Stick with places that have a high turnover of customers (and bring some Imodium AD just in case)!