Air pollution in Europe and North America may be 27 times more toxic than the smog over Chinese cities.
64 years ago, a thick blanket of smog covered the city of London and killed more than 12,000 people.
A British businessman has come up with a novel new way to make money by selling bottles of fresh air.
A novel new technique for dealing with smog is to be trialled in one of China's largest cities.
In a statement about China's worsening smog crisis, one entrepreneur is selling cans of fresh air.