Tube pollution: How toxic is London Underground air and how to breathe cleaner air on your commute

Commuters could be at risk of breathing in dangerous air on the London Underground, a report has found.

The report from the Committee on the Medical Effects of Air Pollutants said there is substantial particulate matter (PM) in the air on the Tube, which is different to the pollution we breathe in on busy roads.

But what does this all mean for the 4.8 million journeys taken each day on the London Underground?

This is the first report looking into pollution on the Tube since 1998. It admits that the little research that has been carried out into the effects of pollution exposure on the underground has been “inconsistent.”

Due to the lack of studies in this area, the report says the full risk to people breathing in pollution cannot be determined.

However, it added: “Given that there is strong evidence that both long and short term exposure to particle pollutants in ambient air are harmful to health, it is likely that there is some health risk associated with exposure to underground PM.”

Peter McNaught, Director of Asset Operations at TfL said of the report: “It is vital that we operate with the very latest understanding of the risks arising from particles in the air, which is why we commissioned COMEAP to undertake this research.

"Although the report emphasises further monitoring and research is needed, it is an important contribution to the study of health effects associated with dust exposure.

“We are committed to maintaining the cleanest air possible for our staff and customers when using the Tube.

"We closely monitor dust levels on the Tube and, through a wide range of measures, ensure that particle levels are well within Health & Safety Executive guidelines.

"We have already enhanced our sampling regime by including tests for additional metals and we will continue to investigate ways we can keep dust and particles to an absolute minimum.”

The lines that run deepest under the city are recorded as having the highest concentrations of PM2.5 – with the northern line identified as particularly polluted.

Despite the concerns raised in the report, which urges Transport for London to find ways of reducing pollution on the Tube, there are ways commuters can reduce their pollution exposure.

Chris Large, senior partner at Global Action Plan, said: “If Tube travel is an essential part of how you get around, there is the possibility of reducing the tube journey and getting more exercise.”

He suggested people travelling on the Tube should get off a stop earlier and walk to their destination - using quieter roads if possible.

However, if tube journeys are one of a number of options, then Global Action Plan’s advice is to switch to walking, cycling or scooting where possible.

According to Large, one of the best ways to reduce the effects air pollution can have on the body is to stay fit and healthy – so avoid smoking and fatty foods that clog arteries and keep up the exercise.

He argued that some people have no choice but to be exposed to air pollution in their daily lives – for example, taxi drivers – but keeping fit and healthy in all other regards is the best way to minimise effects of air pollution.

Global Action Plan does not advise using face masks to protect from pollution.

According to Large, the intended function of a mask is to screen out particulate matter or to clean the air that is being breathed in by using an active ingredient to react with polluting gases in the air.

However, he believes the mask products he has seen on the market may not be able to carry out these functions as effectively as they should.