The toxic gas nitrogen dioxide (NO2) can lead to respiratory disease and can cause the lining of the lungs to become inflamed.
The government is the subject of legal action after failing to deal with the high level of the toxic gas in the country's cities.
Most British cities have plans to reduce traffic fumes to within the legal limit by 2020, however London has insisted that it could not meet the NO2 targets set for it in 1999 until at least 2025.
London has the highest levels of NO2 of any European capital city and the UK has the highest proportion of zones breaching legal limits.
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.
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.
Sentencing Belmar to 16 months behind bars, Judge Michael Gledhill said that the knifeman had a 'fixation' with Buckingham Palace.
The potential grave danger, either to yourself or others was obvious by what you did.
There are countless other people in exactly the same situation as you following the relatively recent changes to the country's benefit system.
But they don't all arm themselves with knives and go to Buckingham Palace, intending to trespass within the grounds or enter the palace themselves. That is why what you did could be described as a stunt.
A knifeman who tried to break into Buckingham Palace to complain about his benefits being cut has been jailed for 16 months. 44-year-old David Belmar jumped over a barrier armed with a six inch knife in October last year.
Belmar was rugby tackled to the ground by armed police in the palace forecourt. Horrified tourists and their children looked on at the gates. The knife was found hidden inside a plastic bag in his jacket pocket.
Details of how the royal children lived at Buckingham Palace over the last 250 years will be revealed at an exhibition next summer. The Royal Childhood exhibition will cover the years from the purchase of the palace by George III in 1761 to the birth of Prince George of Cambridge this year.
It will include photographs, clothing and the children's favourite toys. The exhibition will run throughout the summer opening of the Palace in August and September 2014.
London's own cycling star Bradley Wiggins will receive his knighthood today.
The Olympic gold medallist and Tour de France winner will be honoured for services to cycling in an investiture ceremony at Buckingham Palace this morning.
Prince Charles is to launch a campaign to boost the numbers of young volunteers in a bid to curb gang violence.
The Prince of Wales told the The Mail on Sunday that street murders can occur because young people lack structured activities.
Charles will join the Prime Minister, the Deputy Prime Minister and the Leader of the Opposition at Buckingham Palace this week along with 50 young people to launch a pledge campaign called #iwill.
Charles said that currently only 29 per cent of young people volunteer regularly, but wants 50 per cent of youngsters aged 10-20 to volunteer by 2020.
They [the police] started shouting move back, move back, but we had nowhere to go. The police started pushing us, screaming 'move back, move back'.
There was a fire on the right hand side of the [Victoria] monument and people started throwing things.
- Scotland yard says eleven people were arrested nine for public order offences and two for criminal damage
- Officers in riot gear controlled the crowd, which was part of a pre-arranged Anonymous Million Mask March
- Several similar events were carried out in cities in Japan, Australia, and New Zealand in opposition to austerity cuts, corruption and an increase in state surveillance