We had a yellow sand warning yesterday; when I looked out at the city from the top of our office building, maybe 50 meters above it all, all I could see was nothing. Nothing but yellow fog, that is. It looked sort of like the shop floor of a yellow-car-painting company, or like San Francisco looks if you are wearing yellow sunglasses. Of course my nose, eyes, and face knew something was going on - there was an impalpable suffocation in the air, an unbreathability that most people can only understand after sitting in a smoky bar for a few hours - this stuff is killing us, I'm telling you.

Yellow sand, in case you weren't aware of the phenomenon, is gunk blown off of the Gobi and Taklimakan deserts of central and western China, which becomes airborne in the higher reaches of the atmosphere, before precipitating in Korea, Japan, and sometimes California. Hardly sand, most of the particles are colloidal, meaning that they are smaller than cigarette smoke particles and have a certain ability to actually dissolve partially in the air. (known as a colloidal suspension - this is what milk is ).

There is also evidence that it cools the earth, mitigating the recent global warming trend, so it looks like we are stuck with a necessary evil.

A lot of people wore masks yesterday, and I dutifully wore my fancy microfiber model (although I have a really fancy pancy carbon filter from England, but it's too small for my face and doesn't let enough air through) and when I came home I still felt as though a lot of gunk had gone into my nose. So when I blew it out, all I got is what you see above. Nothing. I suppose that's great news, but then again i remembered that it comes in the form of microcolloidal particles - so even things invisible to the naked eye, like the influenza virus, could be in there (the tv news reported finding influenza in the yellow dust, which would explain the rash of stomach complaints around this time)

When I lived in China I heard some kind of story about the 'yellow sand phenomenon' (called red sand in Chinese) that the government had embarked on one of their legendary, epic, Cecil-B.-Demille-type-employment projects, planting hundreds of thousands of trees in the Gobi in an attempt to reduce the yellow sand phenomenon (Beijing suffers terribly; most of the particles that precipitate there are of the honking big variety, causing even greater respiratory distress).

Naturally they had forgotten to do their homework, and planted some sort of fast-growing deciduous species that all flowered and released pollen at the same time - causing such a rash of allergies in the capital that they had to embark on another Cecil-B.-Demille-project to cut them all down again.

Of course this smacks of urban legend, since I don't have the primary source for this, and its the sort of nonsensical story you'd expect to come from the Sleeping Red Giant....