/ Motoring

Does air pollution from cars affect you?

car pollution

Since London was issued with its first ‘very high’ air pollution alert at the start of the year, much has been written about the impact poor air quality has on our health. But does it affect yours?

Brixton Road in Lambeth, south London, became famous earlier this year when it breached its annual NO2 (nitrogen dioxide) allowance – just five days into 2017.

Later that month, on 23 January, London Mayor Sadiq Khan issued the first ‘Very high’ air-quality warning for the city.

This advises everyone within the capital to reduce physical exertion – particularly if they’re outside and by busy roads.

Cue a whole lot of media attention around the poor quality of the air we breathe.

Much of this has focused on NO2 (one of the NOx gasses), which is produced in large quantities by diesel cars.

And, while some car manufacturers are making progress on reducing the amount of toxic emissions from their models, many have a long way to go.

In our recent tests, we found that, despite universal limits, there are huge differences in the amount of NOx emissions produced by diesel cars from different brands, with Renault and Jeep among the biggest air polluters of the car makers we tested.

How bad is NO2?

So, what impact does NO2 have on your health? Well, there have been a number of scary reports concerning just that.

One study published in 2015 by the Environment Research Group at King’s College London, estimated that Londoners lost up to 88,113 life years to NO2 during 2010.

And it isn’t just London where poor air quality is a problem.

The Royal College of Physicians thinks around 40,000 deaths in the UK per year can be attributed to air pollution.

While a report from the European Environment Agency named poor air quality as the largest environmental health risk in Europe.

It’s widely accepted that NO2 inflames the airways and can lower immunity against lung infections.

Its effects are more pronounced on those who are vulnerable, such as the elderly and those who have an existing lung condition.

The affects

As a result to worsening air quality, major cities around the world are now committing themselves to banning diesel cars by 2025.

But do you notice poor air quality?

As someone with mild asthma, who lives by the sea but works in London, I notice a palpable difference in air quality between where I live and where I work.

That said, it isn’t the air quality that stops me from going out for a run on London’s streets during my lunch hour (it’s usually utter laziness).

But some people really suffer. The British Lung Foundation put me in contact with Janet Morrison, 62, whose existing lung conditions are worsened by traffic pollution.

‘I grew up in London but in 1966, at the age of 11, I moved to Southend-on-Sea in Essex. I had asthma as a child, but was diagnosed with emphysema and then bronchiectasis in my 30s and 40s – I’m now 62.

‘There’s a lot of traffic in Southend. It’s busy during the rush hours, but much worse at the weekend with all the tourist traffic, especially in the summer.

‘When the pollution gets bad, it feels like someone is sitting on my chest. I hate going out when pollution is high, but I can’t let it stop me.

‘I try to manage it with my inhaler, but if I’m driving somewhere in traffic, I have to close the vents in my car to stop the air coming in.’

What about you? Do you notice days when the pollution is bad? Do you have to take any precautions? Or has it never bothered you?

Patrick Taylor says:
6 May 2017

Some useful information from Wunderground:

“Levels of PM2.5 pollution along busy roads are roughly double ambient levels, so you are greatly increasing your air pollution exposure if you drive with the windows open. The highest PM concentrations occur in congested traffic or when driving behind a heavy diesel-driven vehicle. Your exposure is not reduced much by driving with the windows up, if the car’s ventilation system is operated to bring in outside air. While cars are equipped with a cabin air filter which reduces levels of harmful particulate matter sucked in from the road, these filters only reduced PM 2.5 levels inside the car by 29% compared to outside pollution levels, according to one study that looked at a wide range of commonly driven 2010 – 2013 model year cars. This is not much better than when the filter was removed, which resulted in a 22% reduction. Cabin air filters are only required to be effective for particles of 0.3 microns or larger in diameter, and significant lung damage is done by ultra-fine particles smaller than that, which are emitted by cars in great numbers.”

To greatly reduce your air pollution exposure while driving, operate the ventilation system under recirculation (RC) mode (you may need to run the air conditioner to keep the windows from fogging up.) Recirculation mode can achieve a reduction of about 90% in PM2.5 levels, and it takes just three minutes once RC mode is turned on for the air to clear to levels typically breathed in an office. However, recirculation mode also causes passenger-exhaled CO2 to accumulate rapidly above 2500 ppm in the car–over six times the ambient air concentration. Exposure to high CO2 concentrations of 2500 ppm for several hours can significantly reduce decision-making performance, and may cause drowsiness. If you are on a long drive in heavy traffic, it is probably a good idea to turn RC mode off for a few minutes every half hour or so if you are concerned about staying alert and making good driving decisions. Some new vehicles have the feature of periodically switching off the recirculation and bringing in air from the outside for a short period of time during the recirculation setting.”

The article refers to the interesting effects of too much carbon dioxide…..

I would also repeat that the pollution is not only derived from engines but a significant amount derives from brake and tyre abrasion and this is also harmful. The higher incidence of Alzheimers [7-11%] in people living within 50m of busy roads suggest it may be an amalgam of engine pollution, noise stress and debris.

The effects on mothers-to-be and young children one would think very interesting particularly in a pram at exhaust level.

Patrick Taylor says:
6 May 2017

For those wondering about air quality. And usefully these figures based on numbers:

It has not been unknown for companies to go for low rates of air exchange to reduce heating bills. Whether that currently occurs is difficult to know.


It’s a real problem. I have a cpap with an inline filter for extra protection. I change them every month as recommended. They are always black and that is in my bedroom. I sleep with the window open so it demonstrates to me a serious and worrying problem.


The “Weekly Scoop” from Which? tells me….
“For years we’ve complained and campaigned that official fuel-economy figures are inaccurate and can’t be trusted – over 114,000 of you signed up to our ‘Come Clean on Fuel Claims’ campaign to help sort this problem out. Now we have a result. All brand new generations of cars released after 1 September 2017 will have to go through much tougher tests, and this should help close the gap between official and real-life fuel economy figures, plus reduce levels of harmful emissions from cars. The government also states that these new tests – called WLTP and RDE – are being introduced as a way of stopping another Dieselgate scandal from happening.
Read more: http://www.which.co.uk/news/2017/09/would-your-car-pass-the-new-fuel-and-emission-tests/ – Which?

It think it unacceptable that Which? indulge in this kind of “news”.

Firstly, the new fuel and emissions tests have been under development for many years internationally. I don’t know of any involvement by Which? or any effective lobbying. The need for revision of the existing outdated tests was well known and is an EU issue, not one for the UK on its own..

Secondly, the “official figures were not “Inaccurate” and “can’t be trusted” as the outdated NEDC tests that produced them were never devised to yield “real life” fuel consumptions. They were intended simply to be used for comparative purposes, as the advertisements tell us by means of tests conducted under controlled conditions in a laboratory. With changes to car technology they needed revising; the WLTP laboratory test was therefore developed but as well as giving comparative data will hopefully yield consumptions nearer what drivers might expect.

However, consider the variation that will occur in practice for a single model of car; how it is driven – fast, slow, heavy acceleration and braking; the terrain where it is driven – hilly, flat, straight or tortuous roads; how heavily the car is normally laden – full of passengers or just the driver; how well it is maintained. One fuel consumption can never apply to everyone.

There is a danger that Which?, by issuing misleading and inaccurate information, will alienate the organisations it should be engaging with, as well as leading to some disillusionment among those members who want Which? to be “honest and truthful” – to which I might add “balanced and impartial”.


To be fair, it’s true that Which? has “complained and campaigned that official fuel-economy figures are inaccurate and can’t be trusted for as long as I can remember. In fact, so long it simply became part of their car reports, and hardly noticeable.

I do appreciate your point about the test being intended simply to be used for comparative purposes, but that didn’t change the fact that the mpg was widely quoted as a selling point in car adverts.

But I also agree that W? has developed a cheeky habit of spinning news announcements to their benefit.


I’d be interested to learn how Which? evaluates the performance of their press unit. I rarely get the impression that the output rings many bells and has the media jumping on the story. There is occasionally a headline in a national newspaper but half the time the following copy is negative or has been included as a peg for a sensational article with little credit given to Which? for bringing it to attention. Perhaps I am wrong and that the follow-up analysis shows that many column inches [centimetres?] were generated with positive results.


They do seem to manage to get stories featured on BBC’s Breakfast time and the text news quite a bit.


If we are going to have balance, I suggest that we criticise the motor industry for continuing to feature the NEDC figure