Do natural disasters cause Covid-19 cases to rise?
What’s happening? The risk of contracting Covid-19 may be significantly increased with wildfire smoke exposure, a Desert Research Institute study suggests. Using modelling methods, researchers analysed the relationship between PM2.5 – particulate matter from wildfire smoke – and positive Covid-19 tests at a large regional hospital in Reno, Nevada. They found a 17.7% increase in the number of infections between 16 August and 10 October 2020, when the city was most impacted by wildfire smoke. The findings could help develop public preparedness policies for areas affected by wildfire smoke, which is likely to coincide with the pandemic during 2021, the team concluded. (Desert Research Institute, Journal of Exposure Science and Environmental Epidemology)
Some background – Wildfire season is now in full swing in the US and other parts of the world, just as the Covid-19 pandemic is still raging on itself. Air pollution carried by the smoke is said to be even worse for human health than that from other sources such as traffic. Many studies have suggested an associationbetween air pollution exposure and Covid-19 infection, so it stands to reason that a rise in cases would be seen in locations close to where wildfires are burning.
Why the connection? There are established links between air pollution exposure – PM 2.5 in particular – and the development or worsening of health conditions. These include cardiovascular disease and reduced lung function alongside obesity, type 2 diabetes, systemic inflammation, Alzheimer’s disease and dementia. Air pollution can also raise the risk of respiratory infections. It’s important to note that people with these conditions are among those considered to be more susceptible to severe symptoms or death as a result of contracting Covid-19 than other groups.
People living in close proximity to wildfires may need to seek refuge indoors away from their homes to avoid danger. This makes social distancing harder, which is more important indoors where transmission is more likely. Vaccination programmes themselves have also been hampered by severe weather, leading to longer lockdowns and a prolonging of the pandemic.
What else is going on? Flooding events, such as those recently seen in the Philippines, Myanmar, and in parts of Europe, also run the risk of further outbreaks of Covid-19 for similar reasons as people are forced to evacuate without proper social distancing and hygiene measures. Although it’s accepted that the disease is primarily airborne, there has been some suggestion that it could also spread through human faeces and urine. If this is the case, then urban flooding, which is often accompanied with sewage overflow, could also contribute to the ongoing pandemic.
In the future – Climate change will not just increase the number and magnitude of natural disasters like these, it is also expected to give rise to new pandemics. One day will see the back of Covid-19, but what comes after could be even more severe unless we take serious action now.