As I was waiting for the bus this morning, I glimpsed this headline: ‘Is that Dandruff in Your Air Pollution‘? It’s such an unsurprising concept — that particulate matter in the air includes stuff like dandruff and fur — that it hardly seems newsworthy. And yet. The image of all of us wading through a haze of skin chunks is somehow tough to, er, swallow. I can’t help but think of all those salmon swimming through each other’s lice — and how I had the temerity, when we reported that the other day, to think it was strange.