In a study, where lung cells were
exposed to exhaust and brake dust particles,
they became inflamed and less able to
protect against bacteria , while lung tissue was also damaged.
Researchers have found that Metal-particle
dust created by scraping brake pads account for a fifth of all tiny particle
pollution on the roads.
Dr Ian Mudway, who led the research at
the MRC Centre for Environment and Health at King’s College, London, Said“ the focus on diesel exhaust emissions
is completely justified by the scientific literature,”
He said: “There is no such thing as a
zero-emission vehicle, and as regulations to reduced exhaust emissions kick in,
the contribution from these sources are likely to become more significant.”
At the moment, tail pipe fumes make up only 7% of the tiny
particles found in roadside air – tyre wear, clutch scrapings and general road
dust which may not be emitted from cars at all account for the rest.
“But
we should not forget, or discount, the importance of other components, such as
metals from mechanical abrasion, especially from brakes.”
While brake dust makes up 20% of total
roadside particle pollution, non-exhaust emissions make up only 7.4% of
particulates from cars.
The share is set to rise to 10% by
2030, this is partly due to the increasing weight of cars and particularly heavy electric vehicles increasing wear on brakes.
Air pollution causes an estimated 64,000
early deaths a year in the UK. Around three-quarters of these are due to
particulate pollution.
Mike Hawes, Chief Executive of the
Society of Motor Manufacturers and Traders, spoke in July 2019 on the subject:
“The automotive industry is committed to improving air quality and has already
all but eliminated particulate matter from tailpipe emissions. Brake, tyre and road wear
emissions are recognised challenges and emissions from these sources are
not easy to measure.