Is that (Hanoi) pollution from China? Local sources? Both?
My understanding is it’s local (that is, from North Vietnam). What has happened is that a lot of industrial companies have been moving into Northern Vietnam from China because production costs have been becoming too high in China as China modernizes and wages are increasing. Vietnam is also increasingly seen as a friendlier country in which to do business, although they have the same corrupt type of government that China does. But they are encouraging outside foreign investment.