Comment on CMO air pollution report

Colin Walker, Jess Ralston, and Matt Williams are available for further comment and interview.

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By George Smeeton

Information on this page correct as of:

Commenting on a report on air pollution by Professor Chris Whitty, the Chief Medical Officer (CMO) for England [1], on road transport Colin Walker, Transport Lead at the Energy and Climate Intelligence Unit (ECIU), said:

“Many of the tiny particles of pollution that are driving this health crisis come from the petrol and diesel we burn to transport people and goods.

“The shift to net zero with more walking, cycling, public transportation and electric vehicles will reduce the particulates that come from traditional car’s exhausts. Thanks to regenerative braking, EVs cut up to 95% of these tiny particles from brake pad wear. Fears that heavier electric cars will produce more particulates from tyre wear also don’t appear to be playing out in practice”.

On the use of gas for home heating and cooking, Jess Ralston, Head of Energy at ECIU said: “It’s a little-known fact that gas boilers and hobs produce nitrous oxides air pollution, accounting for a fifth of this type of pollution in some areas. Studies show that using hydrogen for heating instead could be even worse. Transitioning away from gas in the home and towards electric solutions like heat pumps also results in cleaner air for us to breathe, lessening the burden for the NHS.”

On emissions from farming and land use Matt Williams, Land Use Analyst at ECIU, said: “Farming emissions are the single biggest source of PM2.5 pollution in the UK. The chemical fertilisers that release these ammonia gases have also climbed in price because many of them are made from gas. Restoring soil health, and using new precision spraying technology, could mean fewer of these chemicals are needed.”

Notes to editors:

  1. The Chief Medical Officer’s Annual Report 2022 on Air pollution is published on 8 December.
  2. The ability to deploy regenerative breaking to reduce speed means that EVs, despite their greater weight, can produce significantly less PM from brake pad wear than an ICE vehicles - estimates are that EVs reduce PM generation from brake pad wear by up to 95%.
  3. PMs from brake pad wear are 9 times higher at urban driving speeds than on fast motorways - this is significant as half of all NEEs occur on urban roads. It seems likely that a transition to EVs will result in a significant reduction in PMs in areas with the higher population densities.
  4. EVs are 24% heavier than ICE, and often more powerful, leading commentators to expect greater levels of tyre wear. Two points:
    1. PMs from tyre wear are greatest on the UK’s motorway network, where fast speeds and a comparative lack of braking means that these forms of NEEs predominate. However, in urban areas where speeds are lower and braking is more frequent, they play a secondary role in PM generation in comparison to brake pad wear.
    2. Furthermore, anecdotal evidence from operators of EV fleets suggests that claims of greater tyre wear on EVs are not playing out in practice, with the lifespan of tyres on EVs being comparable to the ICE vehicles they have replaced.
  5. The UK Government’s Air Quality Expert group has concluded that it, ‘…seems likely that the general move to electric vehicles and regenerative braking will lead to an overall reduction in NEE’ and that, ‘…in locations where brake wear makes a major contribution to overall NEE emissions, it seems likely that there will be a net benefit’ but states that this is yet to be quantified.
  6. The RAF Foundation has concluded that, ‘…cities that have embraced EVs have already demonstrably benefitted from reduced pollution and improved air quality, and this trend shall only continue as more EVs switch to drum brakes, new tyres are developed that reduce nanoparticulate pollution even further, and the UK’s grid becomes ever increasingly powered by clean renewable energy’.

For more information:

George Smeeton, Head of Communications, ECIU, Tel: 07894 571 153, email: