Hong Kong, 1986; Just how bad was air pollution in Hong Kong in the past? Well, as the scientist who set up their automatic air pollution monitoring network and programme is the 198s, I can confidently tell you ... not that bad, really. But there was a lot of soiling from diesel emissions. This 'before and after' shot of men cleaning a building facade in the busy Tsimshatsui area of Kowloon gives a good idea of this phenomenon. Now imagine that muck is in your lungs. Not so easy to clean off now, is it?