For much of the past month, a huge swathe of northern China has been shrouded in a thick layer of toxic smog. Pollution has reached such high levels that Beijing's met office this week issued a warning against venturing out into the snow because of fears it's dangerously contaminated. With pollution now thought to be the cause of more than a million premature deaths a year, our correspondent John Sudworth travelled to China's most polluted city.
Watch the video and answer the questions below.
1. How far is it from Beijing is Shijiazhuang?
2. What record has Shijiazhuang held over the past month?
3. How is the smog impacting children's health?
4. What is the Chinese government investing in?
5. What are the two main sources for all of this toxic smog?
Well, welcome to Shijiazhuang, a city a little less than 300 kilometers from Beijing, and one that over the past month has had the rather unenviable honour of being China's most polluted. In fact, by some measures, it is the most polluted city on the planet over that period.
Of course, it is just an extreme example of a problem affecting a huge swathe of northern China at the moment, with a pollution cloud hanging over this country from the Russian border in the far northeast all the way down to the central cities of Chongqing and Chengdu, a sweep of a few thousand kilometers or so.
Of course, underneath the cloud live hundreds of millions of people, and they are currently struggling with the impact of this toxic air on their lives and livelihoods.
It can be completely dark, as if you're walking in the clouds. The smog impacts my children's health. Coughing is the usual symptom.
I heard some people say they are considering leaving Shijiazhuang, moving to the south of China. Have you ever thought of doing the same?
Of course, I want to leave, but I cannot afford to. I live here. The whole city and the whole country is polluted. You have to go abroad.
Over the past 30 days, the average air quality level in this city has registered as hazardous on the official scale. Amid mounting public anger across China, the government is pledging to clean up the air and is investing heavily in renewable technology, but there are good reasons for caution and some scepticism. The two main sources for all of this toxic smog are the heavy reliance on coal, as the dominant form of power generation, and the high and still-growing levels of car ownership. And neither of those things look set to change anytime soon.
1 300 km
2 the most polluted city in China
3 coughing is the usual problem
4 renewable technology
5 coal (as the main form of power generation) and car ownership