Air pollution is worse than we thought
I got a reality check recently about air pollution being worse than I thought, when I was cleaning the dust/dirt off my patio railing.  I noticed the dust was particularly black, and the whole time I was cleaning it, a familiar smell was in the air.  I finally realized:  it's brake dust!!<p>While I live on a street with many cars driving by all day, I thought being a few storeys up would reduce the amount of pollution from vehicles... apparently not at all!