Grosvenor Place, which runs alongside the Queen's London residence, had the highest level of the toxic gas nitrogen dioxide in 2012.
Researchers found 152 milligrams of the gas per cubic metre of air, with a main contributor being diesel engine fumes. The EU legal limit is 40.
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Six people were injured after they were hit with the substance during an "altercation" between two groups at a shopping in east London.
Save Your Uber in London was set up after it was announced the firm would not have its licence renewed when it expires next week.
Survivors are still traumatised, homeless and want answers.