The issue focused on more than just air pollution in China and its neighbours. They also paid tribute to the UK's Prime Minister David Cameron and said "the whole world will feel the pain of these deaths".But one question has been asked more than once in recent days: how did this happen?As we speak, there are still still those who question the cause of the pollution in Beijing. There are those who question the veracity of the official figures. But there are also those who question the reality of what they