Is there any research on the amount of carbon inhaled by cyclists on busy city streets? Surely there would be serious long-term effects, so should cyclists wear respirators [to filter out pollutants]?
Richard Moore, Somerset.
Dr Scurr replies: Your question is one that will preoccupy many cyclists. Given that they are exposed to the outside air, you would think they would take the brunt of pollution – but research doesn’t back this up.
One of the first studies to show this was by a pioneering GP and urban cyclist, Dr Ronnie Williams, who was concerned about the effects of breathing in pollution while cycling twice-weekly for his commute to St Bart’s Hospital in the 1960s. He measured his own blood carbon monoxide levels using the hospital’s equipment and compared these with the levels in his blood when he made the same journey by bus – and was surprised to find the bus trip resulted in far higher carbon monoxide levels.
While it might sound surprising, studies have shown that on busy city streets, cyclists breathe in less pollution than those in cars or on public transport, writes Dr Martin Scurr
He attributed this to the fact that he was breathing deeply while cycling, so breathed out all the pollutants.
More recent research has been conducted not only on the absorption of carbon monoxide, but also particulate matter (the tiny particles of pollution), nitrogen dioxide, ozone and other pollutants.
These, too, suggest that cyclists breathe in fewer pollutants than people in cars or on buses.
For instance, a 2019 study by King’s College London – a leader in air-quality research – looked at several air pollutants and multiple studies, and found that people in diesel-powered vehicles face higher pollution levels than cyclists.
With regards to your question about wearing a mask, respirator masks with a P3 rating have been established as the most effective against particles and all pollution except gases. But nothing is capable of absorbing carbon monoxide.
If I was a cyclist, I’d use an FFP3 mask – even though they are hot to wear and slightly cumbersome, so may take some getting used to.
I suffer with dry, itchy and inflamed skin inside my ears. I’m using olive oil instead of the prescribed steroid spray – and it’s working well. Could there be long-term side-effects?
Katie Gooding, Hampshire.
Dr Scurr replies: Using olive oil to treat the ear canals is a time-honoured remedy. I’ve never come across an abnormal reaction to its use in this way – in contrast to some of the commercially available products, which may contain preservatives to which some people become sensitised, resulting in inflammation.
You are using olive oil to treat an itchy skin condition in the ear; many people use it to soften ear wax, thus enabling it to be syringed out easily. But one word of advice: do not use warm or hot oil. Not only is it unnecessary to heat it, but it is potentially dangerous.
