How can cyclists protect themselves against air pollution?

A female cyclist attempts to protect herself from air pollution. Image: Getty.

The popularity of cycling in London continues to rise: according to statistics published by Transport for London (TfL), the number of journeys made by bicycle in London grew by 5 per cent in 2018. The transport agency has attributed the upwards trend in cycling to its investment in cycling infrastructure, not least the seven Cycle Superhighways and 12 Cycle Quietways the city now boasts.

Cycling is widely reported to result in health benefits for participants, and cyclists can expect to achieve improvements in both their physical and mental health as a result of switching from public transport or car to a bike. But with air pollution levels remaining stubbornly high across London, should cyclists be concerned that the health benefits they achieve as a result of cycling are actually being outweighed by the dangers posed by increased exposure to air pollution? 

Unlike during the Great Smog of 1952, air pollution today is often invisible to the naked eye. Nonetheless, London breached the European and UK air quality annual limit on 18  March when, for the 36 time this year, levels of pollution particles recorded at a measuring post exceeded the agreed limit. (EU rules allow 35 breaches a year.) Whilst this is a marked improvement on 2018 when the annual limit was broken on the 5 January, it reminds us of the risk that air pollution continues to pose to Londoners today. 

The rise of respirator masks

Anyone who has cycled or walked along one of London's cycle paths in recent years is likely to have seen someone resembling Darth Vader cycling towards them. Protection masks, which are becoming increasingly popular amongst the cycling community, range from cotton surgical masks to respirators with in-built air filtration systems that cover a significant part of the cyclist’s face. 

But do masks actually work and are they worth the investment? 

Cotton masks categorically do not protect wearers against the inhalation of airborne particles. Whilst they can be somewhat effective in protecting against the spread of illnesses, they will not protect a cyclist from air pollution. 

Respirator cycling masks, which range in price from £25 to over £50, are a more sophisticated option. “N99” respirators are said to remove up to 99 per cent of airborne particles from inhaled air. But the particles that cause air pollution today are extremely small, which makes it particularly challenging for respirators to effectively block them from entering the human body. 

Another complicating factor is the fit of the respirator against the human face. Studies have concluded that under “perfect” conditions respirators do effectively filter pollution out of inhaled air. However, when actually fitted to a human face, respirators are often not able to form an effective seal against skin, which ultimately renders them useless. Features such as facial hair and short noses make is particularly challenging for a seal to form. 

The findings of studies into the effectiveness of respirator cycling masks are somewhat mixed – but point to the ineffectiveness of current designs. 


So what can cyclists do to protect themselves? 

The best intervention a cyclist can make to reduce their exposure to air pollution is to avoid the most polluted streets and roads. TfL’s Quietways are an easy way for cyclists to identify the less busy and less polluted roads (although TfL has announced it will be merging the Quietway and Cycle Superhighway networks into a single Cycleways cycle network during summer 2019). 

Cyclists may also consider reducing their cycling speed to reduce their inhalation of airborne particles. The faster and deeper we breathe in polluted air, the more pollutants are delivered to our lungs. Therefore slowing down and reducing their amount of exertion will go some way to protecting cyclists from air pollution. 

Finally, cyclists should check air quality forecasts and make informed decisions regarding their chosen mode of transport on a particular day. TfL provides daily forecasts on its website. 

So should cyclists stop cycling all together? In a word, no. Although there is currently not an effective way to stop yourself from inhaling air pollution whilst cycling, scientists have concluded that the physical and mental health benefits of cycling continue to outweigh the dangers posed by exposure to air pollution. Cycling remains a healthy method of transport for Londoners. 

If you are a cyclist who is concerned about your exposure to air pollution and you are considering investing in a respirator mask, be aware that research suggests they will not protect you effectively. Instead you may want to consider donating the money you would have spent on a respirator to a charity such as Trees for Cities, whose mission is to transform urban areas by creating Urban Forests.

 
 
 
 

Tackling toxic air in our cities is also a matter of social justice

Oh, lovely. Image: Getty.

Clean Air Zones are often dismissed by critics as socially unfair. The thinking goes that charging older and more polluting private cars will disproportionately impact lower income households who cannot afford expensive cleaner alternatives such as electric vehicles.

But this argument doesn’t consider who is most affected by polluted air. When comparing the latest deprivation data to nitrogen dioxide background concentration data, the relationship is clear: the most polluted areas are also disproportionately poorer.

In UK cities, 16 per cent of people living in the most polluted areas also live in one of the top 10 per cent most deprived neighbourhoods, against 2 per cent who live in the least deprived areas.

The graph below shows the average background concentration of NO2 compared against neighbourhoods ranked by deprivation. For all English cities in aggregate, pollution levels rise as neighbourhoods become more deprived (although interestingly this pattern doesn’t hold for more rural areas).

Average NO2 concentration and deprivation levels. Source: IMD, MHCLG (2019); background mapping for local authorities, Defra (2019).

The graph also shows the cities in which the gap in pollution concentration between the most and the least deprived areas is the highest, which includes some of the UK’s largest urban areas.  In Sheffield, Leeds and Birmingham, there is a respective 46, 42 and 33 per cent difference in NO2 concentration between the poorest and the wealthiest areas – almost double the national urban average gap, at around 26 per cent.

One possible explanation for these inequalities in exposure to toxic air is that low-income people are more likely to live near busy roads. Our data on roadside pollution suggests that, in London, 50 per cent of roads located in the most deprived areas are above legal limits, against 4 per cent in the least deprived. In a number of large cities (Birmingham, Manchester, Sheffield), none of the roads located in the least deprived areas are estimated to be breaching legal limits.

This has a knock-on impact on health. Poor quality air is known to cause health issues such as cardiovascular disease, lung cancer and asthma. Given the particularly poor quality of air in deprived areas, this is likely to contribute to the gap in health and life expectancy inequalities as well as economic ones between neighbourhoods.


The financial impact of policies such as clean air zones on poorer people is a valid concern. But it is not a justifiable reason for inaction. Mitigating policies such as scrappage schemes, which have been put in place in London, can deal with the former concern while still targeting an issue that disproportionately affects the poor.

As the Centre for Cities’ Cities Outlook report showed, people are dying across the country as a result of the air that they breathe. Clean air zones are one of a number of policies that cities can use to help reduce this, with benefits for their poorer residents in particular.

Valentine Quinio is a researcher at the Centre for Cities, on whose blog this post first appeared.