London and its suburbs are being described as one of the most polluted regions in Europe.
According to a new paper published by the London Assembly, thousands in the area die each year from diseases linked to air pollution.
London claimed the most dismal score, with 9% of annual deaths attributed to toxic air particulates.
In Westminister, Kensington and Chelsea, pollution is linked to 8.3% of annual deaths.
Bromley and Havering fared slightly better at 6.3% -- but that figure is still above England's overall average of 5.6%.
Related health costs are estimated to be £20 billion a year ($31 billion CAD) -- twice the cost of obesity management and care.
In the report, the Assembly makes several recommendations for improving air quality, including: Retrofitting older buses to cut carbon dioxide emissions, imposing stricter standards on diesel vehicles and public service campaigns prompting car pooling and walking.