Global pollution: is the arctic haze actually industrial smog?

In the case of the Arctic haze, the increasingly sensitive tools of atmospheric chemists seem to have revealed a potential problem where it was least expected. In other places considered to be among the cleanest in the world, such as Hawaii, Samoa, Greenland, and Antarctica, apparent excesses of heavy metals, sulfate, and acidity remain to be fully explained. Some of these may in fact be natural, perhaps resulting from volcanic emissions, for example, but the environmental effects, if any, of true pollutants will have to be evaluated. That analysis will undoubtedly be even more complex than unraveling their chemistry.