It's no wonder. Five days into the year, London has already broken air pollution limits set for the whole of 2017.
Brixton Road is to blame. The road exceeded the hourly limit of 200 micrograms of nitrogen dioxide per cubic metre of air for the 19th time last night.
Under EU pollution rules, that limit can only be broken 18 times per year.
More polluted locations that are expected to break this limit soon include Putney High Street in west London, Brompton Road in Knightsbridge and Neasden Lane in north London, according to measurements by the London Air Quality Network.
Last year the limit was exceeded in just eight days with Putney High Street recording the highest number of breaches (1,443), followed by Oxford Street and Brixton Road.
Most main roads in London breach legal limits on a regular basis, and some even exceed the annual limit in a single day, according to environmental campaigners Greenpeace.
“Air pollution is a major health threat, particularly to children and other vulnerable people, contributing to almost 10,000 premature deaths every year in London," said Sophie Neuburg, a campaigner for Friends of the Earth London.
“Road traffic is the biggest culprit – and diesel is the worst."
Earlier this week, leaders in the Square Mile called on Khan to ban all diesel vehicles used by companies like Uber and Addison Lee by 2020, following new rules that black cabs must be low emission vehicles from 2018 and minicabs from 2020.
London mayor Sadiq Khan has outlined plans to expand the Central London Ultra-Low Emission Zone (ULEZ) by 2019 and charge higher-polluting vehicles more.
But campaigners at Friends of the Earth London say he's not doing enough.
They are urging the mayor to phase out diesel vehicles in the city by 2025, bring in the ULEZ changes as soon as possible and invest more in cycling and public transport.