Clean Air Fund measures a “success” according to TfL

A report evaluating a series of government-funded measures in London to reduce particulate matter PM10 concentrations was presented at the Cleaner Air Conference yesterday

Transport for London (TfL) has published a report evaluating measures put in place as part of the £5 million Clean Air Fund programme to address particulate matter PM10 hotspots in the capital.

The London Mayor secured £5 million government funding in March 2011 to deliver a programme of “innovative” short-term measures, which the report concludes have been a “success”.

TfL's Nick Blades (centre) presented the findings of the Clean Air Fund report at City Hall yesterday (January 22)

TfL’s Nick Blades (centre) presented the findings of the Clean Air Fund report at City Hall yesterday (January 22)

Measures implemented as part of the programme include the fitting of diesel particulate filters on 120 buses selected routes; a ‘No Engine Idling’ campaign and taxi-marshalling at selected ranks; green infrastructure, such as the Edgware Road ‘Green Wall’; and an expanded trial of Calcium Magnesium Acetate (CMA), which is a solution that can help to trap PM10 concentrations if sprayed onto roads and walls.

The findings of the report were presented at the Cleaner Air Conference hosted by the Greater London Authority (GLA) at City Hall on Tuesday (January 22).

TfL’s Clean Air Fund delivery manager, Nick Blades, who presented the findings at the conference, said: “This was an opportunity to be fairly innovative and try out measures to see how they work, although clearly evaluating what are quite small-scale measures can be quite difficult.”

The report states: “Overall the programme has been a success and delivered tangible impacts on awareness, behaviour and PM10 emissions and concentrations.  The CAF programme demonstrates that many of these local measures can play a supporting role to longer term and London wide emissions reduction measures, particularly when seen in the context of their wider benefits, and should continue to be delivered.”

Commenting on the findings of the report, government transport under-secretary Norman Baker said: “It is encouraging to see that London is taking ambitious steps to improve air quality. Londoners have benefited from the £5 million DfT grant for measures to reduce emissions on the most polluted streets. The challenge is to build on the success of the programme to ensure that best practice is spread across the country. Of course, one of the best measures to tackle poor air quality is to move as quickly as possible to full roll out of low emission vehicles.”


Measures evaluated in the report include the installation of a 200 metre square ‘Green Wall’ installed at Edgware Road tube station in November 2011, which trapped 500g of PM10 in a three month period. This scheme involved a variety of herbaceous and shrubby plant species, chosen for their ability to grow vertically and trap high amounts of PM10, being attached to the Edgware Road wall and also on another wall on the Mermaid building near Upper Thames Street.

A ‘No Engine Idling’ campaign was also trialled through the programme to encourage motorists to switch off their engine where possible and raise awareness of the health impacts of adding to PM10 and nitrogen oxide emissions when idling. Following measures such as marshalling at taxi ranks and poster campaigns, the report found a 7% reduction in bus idling at monitored strands in central London and concludes that TfL plans to continue raising awareness of the issue.

The programme also funded an expanded trial of Cleaning and Application of Dust Suppressants, which saw a solution called Calcium Magnesium Acetate (CMA) sprayed onto certain roads and walls in order to trap PM10 and reduce concentrations of the pollutant.

The report concludes that the CMA findings “strongly support the role of dust suppressants to reduce local PM10 concentrations in very specific locations where the proportion of local resuspended PM10 is high and the surface area applicable for treatment can be maximised.”

It adds: “This is an area of further work which could be developed to understand which types of locations may benefit from dust suppressant application.”

The CMA study was carried out by researchers at King’s College London and a full report of their findings as well as more information on the Clean Air Fund is available on the TfL website.

According to the Greater London Authority, the Mayor will announce further measures to improve air quality in February.


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