People with asthma and heart problems in particular are being advised to avoid exercising outdoors as air pollution chokes the capital.



A government paper published in December last year found that up to 9% of deaths in the capital's most polluted areas are as a result of air pollution.



Campaigners Clean Air in London founder Simon Birkett this week accused mayor Boris Johnson of making a "backwards step" in his low emissions policy.



According to Birkett “London has the highest concentrations of nitrogen dioxide (NO2), a toxic gas, of any capital city in Europe."



Due to the current weather conditions, “we are basically stewing in our own juices. Some of that is due to the time of year but it’s also about the failure to tackle traffic pollution."



“What worries us is that the government is not doing enough to warn people about the risks of this pollution."



A new study released today also shows evidence that recovering heart attack victims are more likely to die in smog-filed areas of high air pollution.







And last week, Putney high street was named London's most polluted high street, according to the Evening Standard, with shopkeepers and residents urged to keep their doors and windows shut due to fumes from traffic.



However, the Department for the Environment have released a statement saying “Pollution levels fluctuate according to the weather...Our air quality has improved significantly in recent decades and is now generally very good.”



Concerned city dwellers can find out the latest air quality statistics at londonair.org.uk - created by scientists at Kings College London.





Images via Getty - main image photographed in 2011