Diesel scrutiny shifts to London's building sites

* Diesel generators used on building sites

* Contributes to pollution linked to premature deaths

* Government says plans consultation on generation emissions

By Barbara Lewis

LONDON, Sept 27 (Reuters) - Volkswagen's admission it cheated pollution law has exposed a wider problemof diesel emissions from thousands of generators belching fumesacross building sites and countryside.

In London, where the pollution is aggravated by aconstruction boom, a firm that helped expose the extent of theVolkswagen scandal has shifted its attention to dieselgenerators and is working with city authorities and researchersfrom King's College London (KCL) to analyse the problem.

"It (the Volkswagen scandal) served to rip the lid off allthese related issues about engines," said Nick Molden, CEO ofEmissions Analytics, which helps automotive businesses raisetheir fuel efficiency and reduce emissions.

Since 2011, his firm has been collecting data from dieselcars by attaching measuring equipment to exhaust pipes todemonstrate the gap in emissions levels between driving on theroad and in the laboratory tests Volkswagen rigged usingsoftware known as defeat devices.

For 18 months, Emissions Analytics has also been measuringthe fumes from diesel generators needed at construction sites asmains electricity has to be cut off. Diesel is used as a quick,simple and cheap solution.

Molden said tests of an 8 kilowatt generator, smaller thanmany on construction sites, found it emitted roughly six timesmore nitrogen dioxide than the average London bus and 15 timesmore particulate matter per unit of work done.

There is no question of cheating regulations as new EuropeanUnion law on pollution limits for small generators has yet to bephased in.

Emissions vary depending on the size and age of generatorsand the research is ongoing to get more data.

"We have to have a greater understanding of these machines'generating emissions and how we can prevent them having anegative health impact," Daniel Marsh, senior air qualityanalyst at KCL, said.

PREMATURE DEATHS

Separate KCL research has concluded that nitrogen oxides andparticulate matter, or soot, from diesel cause around 9,500premature deaths annually in London.

For Europe as a whole, the estimate is 400,000 early deathsper year from asthma, cardiovascular disease and cancer.Research also suggests a link between diesel fumes and dementia.

Much of the pollution is from traffic, but construction sitemachinery accounts for an estimated 12 percent of soot and 15percent of nitrogen oxides pollution in London, city authoritiessay.

One of Britain's biggest firms hiring out diesel generatorsis Speedy, which is providing machinery for the researchand itself seeking to innovate.

It estimates there are tens of thousands of small generatorsacross Britain. Speedy hires out around 2,500, including 500 inthe London area.

The firm is working on improving hybrid generators, whichlike hybrid cars store energy as they generate, halvingemissions, and on cleaning fuel to make it less polluting.

Generators are also an issue in the countryside whereemergency backup generation on farmland is encouraged bygovernment subsidies.

The government, which plans a consultation on dieselgeneration, says it represents only about 1.5 percent of backupgenerating capacity.

"Our top priority is ensuring that families and businesseshave a secure, affordable and clean energy supply," a governmentspokeswoman said.

London's new mayor Sadiq Khan has made a priority ofreducing pollution in the city of around 8.6 million people andhas proposed levying an extra charge on the most pollutingvehicles entering the centre of town. (Editing by Adrian Croft)