Exposure to pollen can increase your risk of developing COVID-19 and is not just a problem for people with allergies, according to new research published on March 9th.
Plant physiologist Lewis Ziska, co-author of the new peer-reviewed study and other recent research on pollen and climate change, explains the findings and why pollen seasons are getting longer and more intense.
What does pollen have to do with a virus?
The most important option in our new study is that pollen may be a factor in exacerbating COVID-19.
A few years ago, my co-authors showed that pollen can suppress the way the human immune system responds to viruses. By interfering with proteins that signal antiviral responses in airway-lining cells, it can leave people more susceptible to a whole host of respiratory viruses, such as the flu virus and other SARS viruses.
In this study, we looked specifically at COVID-19. We wanted to see how the number of new infections changed as pollen levels rose and fell in 31 countries around the world. We found that, on average, approximately 44 percent of the variability in COVID-19 case rates was related to pollen exposure, often in synergy with humidity and temperature.
Infection rates tended to increase four days after a large number of pollen. If there was no local blockage, the infection rate increased by an average of about 4 percent per 100 pollen grains per cubic meter of air. A strict blockage reduced the increase by half.
This exposure to pollen is not just a problem for people with hay fever. It is a reaction to pollen in general. Even the types of pollen that do not usually cause allergic reactions have been linked to an increase in COVID-19 infections.
What precautions can people take?
On days with a large number of pollen, try to stay indoors to limit your exposure as much as possible.
When outdoors, wear a mask during pollen season. Pollen grains are large enough that almost any mask designed for allergies will work to keep them out. However, if you sneeze and cough, wear an effective coronavirus mask.
If you are asymptomatic with COVID-19, anything you sneeze increases your chances of spreading the virus. Mild cases of COVID-19 could also be confused with allergies.
Why does the pollen season last longer?
As the climate changes, we see three things that specifically relate to pollen.
One is an earlier start to the pollen season. Spring changes start earlier and there are global signs of pollen exposure earlier in the season.
Second, the general pollen season gets longer. The time you are exposed to pollen, from spring, which is driven mainly by tree pollen, to summer, which is weeds and grasses, and then autumn, which is mainly ragweed, is about 20 days longer in North America was now in 1990.
As you move to the poles, where temperatures rise faster, we find that the season becomes even more pronounced.
Third, more pollen is produced. My colleagues and I described all three changes in a paper published in February.
As climate change increases the number of pollen, this could lead to a higher human susceptibility to viruses.
These changes in the pollen season have been going on for several decades. When my colleagues and I looked back at as many different pollen storage records as we could find from the 1970s, we found solid evidence to suggest that these changes occurred at least in the last 30-40 years. for years.
Greenhouse gas concentrations are rising and the Earth’s surface is warming and this will affect life as we know it. I have been studying climate change for 30 years. It is so endemic to the current environment that it will be difficult to look at any medical problem without even trying to understand if climate change has already affected it or will do so.
Lewis Ziska, Associate Professor of Environmental Health Sciences, Columbia University.
This article is republished from Conversation under a Creative Commons license. Read the original article.