Air pollution and coronavirus

Scientists looking for an explanation as to why some people develop more severe coronavirus disease have identified air pollution as one possible cause. A preliminary study from a group at the University of Cambridge shows that Covid-19 death rates tally with bad air hotspots. Marco Travaglio is one of the PhD students conducting the research, and he spoke to Chris about his findings, which are currently on the "medRxiv" platform awaiting peer review...

Marco - What we did was to use publicly available data to look at air quality across different regions in England and what we tried to do was to find an association between air quality and the severity of coronavirus in England.

Chris - When you say air quality, who's making those measurements and how?

Marco - The measurements were made by the European Environmental Agency and they are measurements made according to international standards of air quality.

Chris - And you're asking, I know what the air quality is doing in a given area and I know what the death rate is from coronavirus infection, Covid, in that area. Is there any kind of relationship?

Marco - That is precisely what we did. We tried to investigate if there is any association between deaths and cases from coronavirus and the air quality in that specific area in England.

Chris - Was it retrospective air quality measurements? Because of course at the moment with the lockdown and everything and people changing behaviour because of coronavirus, air quality is changing quite a bit at the moment.

Marco - That is a very good point. We wanted to look at retrospective air quality for precisely this point. We cannot rely on air quality after the outbreak of the virus because we know that with the lockdown measures that have been in place, the air quality has significantly improved. So we only looked at data prior to the outbreak. So this is data for the year 2018.

Chris - And what did you find? Is there a relationship?

Marco - Yes. So we found a significant relationship between air quality measures in England and coronavirus deaths and cases. And again, this is only preliminary and more research needs to be done, but the association was significant at this stage

Chris - And what, the interpretation is if you breathe bad air, you're more likely to die of coronavirus if you catch it?

Marco - Yes, that's, that's the conclusion of the study. The conclusion is that there might be a link between air quality and coronavirus. And the reason for that is because some particles in the air can cause damage to certain organs in your body. This includes the lungs and of course if the function of the lungs is compromised, knowing that the virus attacks precisely these parts of your body, you can imagine that the virus can have a more detrimental effect on your health.

Chris - And can you be reasonably confident that it's not just that where you have lots of people, you therefore get lots of pollution. But if you've got lots of people catching coronavirus, you're going to get lots of deaths as well. There's definitely a relationship there involving the pollution.

Marco - So this is something that we haven't looked at, so I'm not overly confident that if you go to an area with a higher number of people, there could be lower levels of air pollution, but this is something that would be interesting to investigate in the future.

Chris - And of course one other side effect of the lockdown, with people staying at home, is that air quality is stupendously good compared to, you know, a year ago. So has an indirect effect of the lockdown been improved air quality, and therefore could part of the reduction in numbers of cases and deaths be because the air quality is better?

Marco - This is something that's been going around in the news and I think it's very interesting to look at. Air pollution levels have been going down as part of the measures implemented by the government. I think it would be interesting to see if this can have any impact on the possibility of a second wave. If there is a strong association between air pollution and number of deaths, and cases from coronavirus, you would imagine that long term decrease in air pollution could lead to potentially better defense mechanisms being applied by our immune system to respond to a potential second wave. Of course, it's too early to make any conclusion, but this is something that could be potentially interesting to look at in the future.