london congestion charge did not improve air quality - air cleaner

Ewen said that the fees charged by drivers who want to drive through London may have cleared the road, but the £ 8 charge does not help much with the air.
A new study found that levels of pollution in urban congestion toll areas changed very little before and after city implementation charges.
Some pollutants even rise.
But expanding control over the rest of London should reduce smog, said Frank Kelly, a researcher at King's College London, who published the analysis at a meeting of the Institute of Health Effects in Philadelphia this week.
"If the area is expanded, then you will be able to have a slight but significant impact on air quality and possible health," he said . ".
On 2003, London began hitting drivers with a toll of £ 5, entering the 21-square-kilometer area of the city center.
Since then, the charge has increased to £ 8.
The number of cars on the road has decreased by 2006, while the number of buses has increased by 25%, free of tolls.
"The plan has never taken into account air quality or people's health," Kelly said . ".
But to measure whether the cost will improve air quality, his team collected air quality measurement data before and after the start of the charge in London for more than two years.
Kelly's team noticed that there was almost no change in contaminants such as smoke, diesel soot and carbon monoxide.
The content of nitrogen oxides has increased slightly-Kelly believes this is because filters on diesel buses capture soot but emit gas.
Spokesman for London traffic (TfL)
He told the New Scientist that congestion charging can reduce nitrogen oxide emissions by 8% and particulate emissions from diesel engines by 15%.
"Many factors mean that these factors do not necessarily contribute to a significant improvement in air quality, including the chemical reactions that occur in the atmosphere, the import of pollution from other regions, the weather itself," TfL said.
Cleaner air could bring the city's latest driving charges, known as low-emission zones, Kelly said.
Truck, bus and large truck drivers have had to cough since November 2007
If their vehicles do not meet the pollution standards, 200 enter most of London.
Kelly's team now plans to determine whether new restrictions will improve the air and people's health.
"If you can prove good for health, then you will imagine that the public will be more enthusiastic about the plans they have to pay for every day.
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