Has any research been done into the amount of carbon that cyclists breathe in on busy city streets? There would certainly be serious long-term consequences, so should cyclists wear respirators (to filter out pollutants)?
Richard Moore, Somerset.
Dr. Scurr replies: Your question will concern many cyclists. Considering they’re exposed to the outdoors, you’d think they’d bear the brunt of the pollution – but research doesn’t support this.
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 a week for his commute in the 1960s to St. Bart’s Hospital. He measured carbon monoxide levels in his own blood using hospital equipment and compared them to the levels in his blood when he made the same journey by bus – and was surprised to find that the bus journey resulted in much higher carbon monoxide levels.
Although it may sound surprising, studies have shown that cyclists on busy city streets inhale less pollution than cyclists in cars or on public transport, writes Dr Martin Scurr.
He attributed this to the fact that he took deep breaths while cycling and exhaled all the pollutants.
More recently, research has been done on the absorption of carbon monoxide, as well as particulate matter (the small particles of pollution), nitrogen dioxide, ozone and other pollutants.
These also suggest that cyclists inhale fewer pollutants than people in cars or buses.
For example, a 2019 study from King’s College London – a leader in air quality research – looked at several air pollutants and multiple studies, and found that people in diesel vehicles face higher levels of pollution than cyclists.
Regarding your question about wearing a mask, respirators with a P3 rating have been found to be the most effective against particulate matter and all contaminants except gases. But nothing can absorb carbon monoxide.
If I were a cyclist I would use an FFP3 mask, even though they are hot to wear and somewhat cumbersome, so it may take some getting used to.
I suffer from dry, itchy and inflamed skin in my ears. I use olive oil instead of the prescribed steroid spray – and it works 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-honored remedy. I have never encountered any abnormal reaction to using it this way – unlike some of the commercially available products, which may contain preservatives to which some people become sensitive, resulting in inflammation.
You use olive oil to treat an itchy skin condition in the ear; many people use it to soften earwax, making it easy to flush out. Only one piece of advice: do not use warm or hot oil. Not only is it unnecessary to heat it, but it is also potentially dangerous.