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April 16th 2020

This once in a century draconian quarantine event is bringing to light many aspects of our regular everyday life that are not beneficial. With the lack of physical movement, i.e. cars, planes, trains, etc..., we have seen a huge reduction in air pollution. You can actually feel it when you are outside. The air in North Carolina now feels like my trips to Jackson Hole in Wyoming. Now this is lovely from a feelings perspective, but what about the science of the health effects?

The first set of data to look at this topic says that increased particulate matter at 2.5 micron size known as PM 2.5 is associated with increase death from COVID19.

Dr. Wu and colleagues looked at the COVID relationship with long term air pollution exposure and found that for just 1 microgram/cubic meter of PM2.5 increased over time there was a 15% increase in COVID death rate. (Wu et. al. 2020) Essentially, the longer you are exposed to air pollution, the more likely you are to have increased inflammatory lung issues and thus succumb to COVID.

The reasons behind this effect are based on many studies showing that the PM 2.5 particles enter the deep lung tissue like the critical type 2 pneumocyte and trigger an inflammatory reactive oxygen species reaction locally that can up regulate the inflammasome and other local innate immune responses like neutrophils damaging the tissue in advance of a viral invasion. (Cho et. al. 2018)(Wang et. al. 2017) This allows the virus to do more damage rapidly as the immune system is pro-inflammatory indiscriminately and not pro viral killing as the immune shifts towards TH2 polarity like that seen with asthma/allergies.

Now fast forward to the clean air that we are experiencing now. Are we seeing a reduction in heart attacks, asthma attacks and other air pollution related diseases? That data will emerge in the coming weeks to months. My intuitive guess based on what we are seeing in clinic and just my understanding of the science is that there will be a significant shift in negative outcomes with the cleaner air. We are seeing significantly less asthma related illness despite being in the throws of allergy season in pollen infused North Carolina.

This COVID discussion and the previous 6 point to facts that are coming to life here during the COVID era. We as a society need to demand clean air, clean water and clean minimally or better yet unprocessed foods to consume. These are serious drivers of chronic unremitting inflammation that put all Americans at risk for worse disease of the chronic nature and as well of the infectious pandemic nature. I for one am frustrated that we as the electorate have yet to ever meaningfully address the most important aspect of life, survival without disease by mandating clean water, air and food.

Dr. M


Wu Harvard University Article
Cho Inter J Environ Res Public Health Article
Wang Nature Scientific Reports Article
National Geographic Air Pollution Article
Guarnieri Lancet Article

From Cho et. al.: Particulate matter (PM) is a complex mixture of solid and liquid elements that are distributed in the air. Most fine PM (PM2.5) is from anthropogenic emissions and a few are from natural emissions, with the major sources of anthropogenic emissions being industry, coal combustion, and traffic pollution. The components of PM2.5 also exhibit variety in different seasons and cities. Accordingly, the composition, size, biological properties, and physical properties of particles are related to the region, season, and change over time [1,2]. Differences in pollution levels are generated from various pollution sources. The main components of PM are heavy metals, carbon sources, sulfate, ammonium, nitrate, and various ions. In ambient air, several gas pollutants are generated from the same sources as PM pollution, such as carbon monoxide, ozone, nitrogen oxides, and sulfur dioxide. Gas pollutants combined with PM might have adverse effects on human health. The adverse health effects of PM on the progression of diseases mainly depend on gender due to exposure differences, hormonal status, life stages, and other factors