New consumer research has shown that 57% of women spend more time in a car when heavily pregnant – likely to be a result of walking, cycling and using public transport becoming increasingly difficult. As pollution levels are nearly double inside a car compared to walking, this can be the equivalent of a minimum of 2.6 million UK babies being exposed to additional air pollution before they are born over the past 6 years.

The research, launched ahead of this year’s Clean Air Day, is a bid to:
  • raise awareness of the effects of air pollution on pregnant women and the next generation
  • call on the public to drive less frequently to reduce the level of pollution
  • highlight ways that pregnant women might avoid high levels of outdoor air pollution, such as splitting your journey across more than one mode of travel, working from home if your work allows and getting shopping delivered to your door.s.

“The rest of society needs to recognise that for pregnant women sometimes travelling in a car is the only option and that we all have a role to play in reducing the pollution affecting the next generation,” says Chris Large of environment charity Global Action Plan, the organisers of Clean Air Day, which takes place on Thursday 20 June. “In the same way we would consider smoking in front of pregnant women as harmful to the babies’ health, so should we think of idling in our cars so causing unnecessary pollution as equally socially unacceptable.”

Babies are affected too

Many people do not realise that even before their children are born they can be affected by air pollution and that it can be passed from the mother to the baby. A number of research studies have recently shown that:

  • there are links between being exposed to high levels of air pollution and an increased risk of miscarriage by 16%*1
  • in Greater London, 3% of low birth weight cases are directly linked to exposure to air pollution (PM2.5) during pregnancy*2  

A number of studies have been undertaken that demonstrated that there is double the amount of air pollution when travelling by car compared to walking.

New Opinium research, commissioned for Clean Air Day, found that:

  • Up to 57% of women had increased their use of cars and taxis in the latter stages of pregnancy.
  • A separate piece of research found that only 16% of mothers were able to regularly work from home during their third trimester. Apart from roles where it was not possible to work remotely, the biggest reason given for not working from home more frequently was a lack of company support.
In advance of this year’s Clean Air Day, Global Action Plan has developed information and resources on the Clean Air Day 2019 website. These provide:
  • information on how the public can minimise the exposure to air pollution by their families and the next generation
  • top tips on how pregnant mothers can protect themselves, such as different ways to travel into work, and shopping locally to avoid pollution
  • tips and information about working from home, including a template letter to send to employers asking to work from home due to the risks of air pollution.

Professor Jonathan Grigg, Professor of Paediatric Respiratory and Environmental Medicine at Queen Mary University of London, said: “Air pollution is having a devastating impact on the lives of everyone, particularly children, and embryos. These health impacts can include increased risk of developing pneumonia and asthma, and lower lung function growth. This just illustrates how vital it is that we all take action to reduce air pollution, and the need for more stringent standards and policies to address this issue.”

Chris Large says: “This year’s Clean Air Day 2019 we have put a spotlight on some of the lesser known issues with air pollution, such as indoor air pollution and the potential damage caused to unborn babies. By highlighting the impact that air pollution can have on people’s health, including unborn babies, we hope that we can encourage everyone to do more to tackle air pollution and protect their family’s health.”

Says pregnant mother Celia Wyndham, 36: “I didn’t know a lot about air pollution and am really worried to learn that air pollution in a car can be  worse than outside. I often collected my daughter from nursery in the car. Now, though, I’ll probably walk more instead of travelling by car.”

As part of their mission to raise awareness of the effects of air pollution and what people can do about it, Clean Air Day has launched a set of online guidance specifically aimed at parents and families, with tips on how people can avoid air pollution and better protect their health.

Find out more at




*Reference sources of the impacts of air pollution on unborn babies:
*1          A 10-ppb increase in seven-day average levels of nitrogen dioxide was associated with a 16% increase in the odds of spontaneous pregnancy loss.  Reference source:  Acute effects of air pollutants on spontaneous pregnancy loss: a case-crossover study. Feb 2019,

*2          “In Greater London, a study found that 3% of low birth weight cases are directly linked to exposure to air pollution (PM2.5) during pregnancy.” The scientists found a 15% increase in risk of low birth weight for every additional 5 micrograms per cubic metre (µg/m3) of fine particle pollution.  The average exposure of pregnant women in London to fine particle pollution is 15µg/m3, well below UK legal limits but 5µg/m3 higher than the WHO guideline. Cutting pollution to that guideline would prevent 300-350 babies a year being born with low weight, the researchers estimated. Reference source:   Impact of London’s road traffic air and noise pollution on birth weight: retrospective population based cohort study. Dec 2017.

*3        “For those 50% of children being driven to school, the situation is in fact worse. They are exposed to double the pollution inside a vehicle compared to those walking on busy streets.” Reference source: Clean Air Day 2018 media release:
Featured image: Celia Wyndham, 36, Recruitment Consultant, London.  Credit: Neil Baird/Clean Air Day