Geographically challenged; Maybe the smoke got to my brain

On the topic of the aforementioned blaze in Hemel Hempstead, I had forgotten the geographical location of my current client. It turns out that I’m not very far from the site of he explosion, which explains the big black cloud in the sky and the fact that all the local school kids have been told to stay at home. That last bit backfired though. Instead of being indoors at school, they’re outdoors hanging out with their friends.
 
The extent of the cloud can be seen here.
 
I must admit I’m somewhat confused how, according to the BBC, there is no real pollution or health danger from a gigantic black cloud of burning oil…