Air Pollution In Esher – The Worst in Elmbridge

Air Pollution in Esher is the worst in Elmbridge and urgently needs to be addressed. On 24th February the Elmbridge Council Environment committee held a short meeting to approve a draft Air Quality Action Plan. The meeting and report can be found here but I warn you – the summary document is 60 pages and the status report is 235 pages! So, I have tried to distill this down to the key points.

There is no easy answer here. If we, as Esher Residents, really want to tackle air pollution then it will require radical changes. Are we prepared for that? Towns such as Bath and Oxford are introducing clean air zones. Could we do that here? Would there be uproar – from residents or from the ‘through traffic’ that blights Esher?

There will be an 8-week public consultation, in the form of an online questionnaire, which will run from March 2021. Hopefully this article will help give you a better understanding of the facts if you want to take part.

Note: the reports and monitoring are all done in Esher, Cobham, Weybridge, Walton, Hampton Court, Molesey and Hampton Court. Unfortunately, Hersham and Oxshott were overlooked despite the A244 causing air quality problems in both villages. Apologies to our supporters in Hersham Riverside but pollution knows no boundaries so this information and any actions should also be relevant to Hersham.

What Air Pollution Do We Experience in Esher?

The main air pollutants in Esher are:

  • Nitrogen dioxide (NO2) – primarily from road vehicles. Domestic and workplace gas use is also a major contributor.

    At high levels NO2 causes inflammation of the airways and long-term exposure may affect lung function. NO2 also enhances allergic reactions in sensitive individuals. High levels can have an adverse effect on vegetation, contribute to acidification of sensitive habitats leading to loss of biodiversity at distant locations. It also contributes to ground level ozone, which causes ill-health and damages vegetation.
  • Particulate matter PM10 and PM2.5 – Particulate Matter is categorised on particle size (PM2.5 for particle diameter < 2.5µm, PM10 for particle diameter < 10µm). PM is primarily from combustion although it can be natural (e.g. Saharan dust). In the UK, the biggest human sources are stationary fuel combustion, transport and construction. Road transport generates PM from tyre, brake and road wear and to a smaller extent from engine emissions.

    Short-term and long-term exposure to PM can cause respiratory and cardiovascular illness and mortality. The WHO believes exposure to finer particles (PM2.5, which typically are 2/3 of PM10 emissions) has the most impact on health, but even coarse particles (between PM10 – PM2.5) have some impact.

What is a Safe Level?

Generally, if you are in a good state of health, moderate air pollution levels are unlikely to have serious effects. However, elevated levels and/or long term exposure can lead to serious health issues – mainly affecting the respiratory and inflammatory systems, but it can also lead to heart disease and cancer. People with existing lung or heart disease are more susceptible to air pollution and at lower concentrations.

The UK targets for the main pollutants we have to contend with locally are:

– annual average < 40 µg/m3
– not to exceed 200 µg/m3 more than 18 hours per year

– annual average < 40 µg/m3 (note Scotland’s target is 18 µg/m3)
– not to exceed 50 µg/m3 more than 35 days per year

– annual average < 25 µg/m3 (Elmbridge’s target is 10 µg/m3 by 2030)

We should aim to be well under these averages. Levels will fluctuate by time of year and throughout the day so there will be times when the pollution levels significantly exceed the average.

What NO2 Levels Do We See in Esher?

Only NO2 levels are actively monitored in Esher. We have 9 NO2 Air Quality monitoring points at the locations shown on this map:

Air Monitoring Stations in Esher

The annual average NO2 measurements from 2015 to 2019 show that an initial decline is now reversing with 4 monitoring points exceeding the target level: the worst being at the A3/Copsem Lane roundabout; the next being on the High St outside the Princess Alice shop; and also on Church Street.

How does this compare to the rest of Elmbridge? Esher has the two highest NO2 pollution monitor results – only one site in Weybridge has a value over 40 µg/m3.

If we examine the data by month in 2019 then we see that some months such as February have almost all sites exceeding the 40 µg/m3 level with the worst value hitting 64 µg/m3!

How Bad is NO2 in Esher Compared to London?

London’s annual average roadside NO2 levels in 2017/18 was 45 µg/m3 with a peak month of 55 µg/m3 in Jan 2019. If we average all the roadside monitoring spots in Esher then we have an annual average of 39 µg/m3 with a peak of 50 µg/m3 in Feb 2019. We may not be quite as bad as London, but we aren’t that far behind.

What about PM10 and PM2.5 Levels?

PM10 and PM2.5 are not actively measured in Elmbridge because they are assumed to be below the targets. The levels quoted in the reports are based in modelling and for Elmbridge as a whole the 2017 annual average PM10 = 18 and PM2.5 = 11 µg/m3. However, the 50 µg/m3 PM10 level is exceeded on daily measures along the A3 and M25.

Is Local Traffic Mostly to Blame?

For NO2 – Yes. But for PM10 and PM2.5 there is a lot more background effect. The three maps below show NO2, PM10 and PM2.5 for Elmbridge. You can see NO2 is particularly high along the roads (M25, A3, A244, Portsmouth Rd/High St), PM10 is still high along the roads but not to the same degree and PM2.5 is much more even except for the A3 and M25.

Elmbridge pollution map 2017 for NO2, PM10 and PM2.5

The breakdown, shown below, of the pollution by source type shows that for NO2 there is a major contribution by exhaust emissions from Diesel Cars (up to 24% in the worst area – A244) and from Light Goods Vehicles, which are mostly diesel, (up to 21% in the worst case). However, for PM10 and PM2.5 exhaust emissions for all local vehicle types contribute only 2% even at the worst area. Other road sources such as brake wear, tyre wear and general road wear contribute up to 10% in the worst area. But much of the PM emissions are from background and other sources.

What are the Background and Other Sources?

Background sources are pollutants blown here from outside the area. This may be combustion from commercial, residential and agricultural sectors and industrial pollution. But it will also be vehicle exhaust pollution and brake/tyre and road wear from vehicles (including our own) being driven outside our area, e.g. in London or on the M25. Of course, some of our pollution will be blown by the wind to other areas.

Additionally, smoke from bonfires, BBQs, open fires or wood burning stoves adds to PM levels – both inside the home and outside. There are several measures you can take to reduce the impact – see the suggestions at


The Elmbridge Draft Air Quality Action plan for 2021-26 sets a 37% reduction target for NO2 in Esher to bring the level to 36 µg/m3. Several strategies have been proposed at both Surrey and Elmbridge levels to achieve this, including:

  • Encouraging Electric Vehicles (EVs)
  • Re-routing HGVs
  • Encouraging more cycling including local cycle to work schemes
  • Encouraging schools to have more pupils using bus services or walking
  • Encouraging lift sharing
  • Increasing appeal of public transport and adjusting routes to maximise benefit for the 1st and last mile
  • Car clubs
  • Reducing council miles driven
  • Improving public rights of way
  • Replacement of gas-fired boilers in council buildings
  • Encouraging remote working for council staff where possible

Some of these actions will help but others won’t make a massive reduction in air pollution. But there is no easy answer here. For example, a wholesale switch from Diesel to Electric vehicles would help NO2 emissions but Electric cars still contribute brake/tyre/road wear to PM levels. The council’s own contribution through its vehicles and buildings is only a small part of the problem.

What’s Next?

Even a 25% reduction in car journeys would only reduce NO2 by 20% versus the target reduction of 37%. If we, as Esher Residents, really want to tackle air pollution then it will require radical changes. Are we prepared for that? Towns such as Bath and Oxford are introducing clean air zones. Could we do that here? Would there be uproar – from residents or from the ‘through traffic’ that blights Esher?

The conclusion of the Committee meeting was that there will be an 8-week public consultation, in the form of an online questionnaire, which will run from March 2021. Hopefully this article will help give you a better understanding of the facts. Once the consultation form is published, we will let you know where to find it.

David Young – February 2021


Elmbridge BC – Individual Cabinet Member Decision Making – Environment – 24 Feb 2021

Elmbridge – Local Air Quality

Defra, UK – Air Information Resource

Air quality in Spain: 15 million Spaniards are breathing air the EU considers polluted (

Wood burners triple harmful indoor air pollution

London Average Air Quality Levels – London Datastore


  • We now have 2 100% electric cars. Yet you have removed free car parking in Elmbridge car parks. Why?
    We back onto the A244. The introduction of traffic lights at Milbourne Lane junction 10 years agogreatly increased pollution.
    Our neighbours have garden fires all the year round.
    The greatest way to reduce pollution on the through roads would be to close off the A244 at the A3 junction and create a n entry and exit at the A3 Hinckley Wood junction. A new road should be built from the scilly isles to Hersham across the golf course at Thames Dutton passing on the southern edge of Sandown Park and Hersham Golf Course to rejoin the A244. This would divert most of the through traffic out of Esther.


    • Hi David, thanks for you comment.
      As a fellow electric car owner, it was nice to have the free parking but it didn’t encourage me to buy the car. The money would be better spent improving the electric car infrastructure in Elmbridge to encourage more people to make the switch.
      Bonfires are a problem – yesterday we had to lock up our house for the whole day because of a neighbour’s bonfire. Some people have just always had bonfires and feel they have too much garden waste for their bins. We need to find a way to persuade them to change to reduce the nuisance to neighbours and the pollution.
      Your proposed new Esher bypass is rather drastic and would destroy a swathe of green belt. The trouble with many schemes is that they just push the traffic from one area to the next. For example the Low Emission zone in London which reaches out to the A243 has pushed more HGVs onto our A244. We need to look at ways to reduce traffic and/or spread it out more evenly.
      Please keep the ideas flowing. This is an important topic that we need to tackle.
      Rgds David


  • Pingback: Air Pollution Consultation | Esher Residents Association

  • Air pollution is the presence of contaminants or pollutant substances in the air at a concentration that interferes with human health or welfare.


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