Scientists have called for a crackdown on polluting construction machinery after research showed the sector was the dominant source of dangerous black carbon emissions in an area of central London.
A study led by academics at the University of Manchester called for tightened regulation for non-road mobile machinery (NRMM) to address human health concerns.
Their research, carried out in partnership with China's Zhejiang University as well as the UK Centre for Ecology & Hydrology, the University of York and the National Centre for Atmospheric Science, found substantial enough evidence to raise concerns about black carbon emissions from the construction industry in central London.
The study measured levels of various substances from the BT Tower in the heart of the capital.
After analysing the results from two seasons, comparing different gases and considering other factors, the scientists concluded the construction sector was the dominant source of black carbon emissions in the area.
They noted that the substance, which is a major contributor to climate change and one that can quickly reduce warming if tackled, also had significant health effects.
The report noted that the Ultra Low Emissions Zone (ULEZ) for regular highway traffic imposed higher standards than were placed on non-road machinery.
In the footprint area, the policy for NRMM emission-control lags behind those for the road vehicle standard level, and is likely the reason why construction black carbon emissions stand out, it said.
Under rules that came into force at the start of this year, most off-road moveable industrial equipment with internal combustible engines must meet Euro IV standards to operate within Greater London.
This effectively keeps their exhaust emissions broadly in line with cars registered between 2006 and 2010.
The next milestone is currently expected to come in 2030, when NRMM used in the capital will have to meet the higher Euro V standards.
Meanwhile, ULEZ requires diesel cars to meet Euro VI, which came into force for new cars in 2015.
The University of Manchester report said: Black carbon concentrations in London have significantly decreased since the introduction of the ULEZ and the use of more efficient diesel particulate filters in Euro VI road diesel vehicles.
To meet the World Health Organisation guidelines for urban air quality and address human health concerns, air quality in London can be further improved by introducing tightened regulation for NRMM.
The mayor of Londons office has been contacted for comment.
