Due to COVID, many governments and organisations have been mandating or recommending masks on public transport for the past few years. However, recent findings show that masks might be even more important on public transport than we thought. Why? Because when travelling, we may be exposed to more than just COVID and viruses. 

This information came to light after a recent University of Cambridge study found that the London Underground is polluted with metallic particles small enough to end up in the human bloodstream. Considering how many people use the London Underground daily, this finding is very worrying.

It is worth noting that we don’t know if the predominantly maghemite particles are harmful to human health. However, it seems likely they are best avoided. This is furthered by the fact that while maghemite makes up a large chunk of the pollution in the London Underground, it isn’t everything. 

A different report found the metro in France had elemental and organic carbon particles alongside maghemite. While there isn’t enough data for a conclusive answer, data suggests the possibility of cardiovascular effects, inflammation and oxidative stress caused by the pollution. 

While there is still a lot we don’t know about the pollution in metro and train systems, it’s best to avoid these particles whenever possible. This means donning a well-fitting high-performance mask such as an N95, KN95 or FFP2 mask. Furthermore, it’s best to stick to well-ventilated areas whenever possible.