Other highly polluted areas include Oxford Street near Marble Arch, which registered at 150 micrograms, and Cockspur Street near Trafalgar Square on 138 micrograms.
The fourth and fifth locations were Park Lane and Knightsbridge - which measured 135 and 134 micrograms respectively.
More top news
Police were called to Kilburn High Road at 5.20pm after reports of a shooting.
In just 24 hours the offer was retweeted more than a thousand times on Twitter.
What a year it's been full of ups and down, turmoil and change and it seems events here in London have got the entire nation talking.