Recent studies show that areas with higher pollution levels may be more vulnerable to coronavirus on dust particles.
This is especially relevant if you are responsible for maintaining any kind of unpaved road surface. These could be mining or industrial haul and access roads to township and county roads. Even agricultural or energy farm roads are vulnerable.
The reason is that fugitive dust (in other words, particulate matter that doesn’t come from a single source, like a smokestack or tailpipe) is a significant source of pollution. According to a report by the EPA, fugitive dust makes up almost 50% of all sources of PM10, and approximately 20% of PM2.5, in the U.S.1 So if pollution helps coronavirus, you can bet the dust particles from your unpaved road affect its spread and impact as well.
The harmful effects of this fugitive dust on the health of employees, visitors or community residents are well-known. PM10 particulate matter, which invades people via the nasal passages and the throat, causes irritation to the respiratory tract and eyes. PM2.5, which can penetrate as far as the lungs, contributes to respiratory illnesses such as asthma or pneumonia, cardiovascular problems and even, in extreme cases, cancer. Many of the harsh metals found in fugitive dust, especially around industrial sites, adds to or worsens these health effects.2
Recent studies show that the coronavirus on dust particles is perhaps a serious issue.
The Harvard Study: Higher Levels of PM2.5 Associated with Higher Fatality Rates from Coronavirus
The first way that this happens is that people at industrial facilities or in communities with high pollution levels already have damaged respiratory systems from lengthy exposure. This makes them more susceptible to COVID-19.
A nationwide study conducted by the Harvard University T.H. Chan School of Public Health collected data from 3,080 counties across the U.S. (accounting for 98% of the population). Their results were startling. If the average particulate matter had been lowered by just one microgram per cubic meter in Manhattan over the past 20 years, it could have saved as many as 248 lives by this point in the pandemic.
That change of a single microgram makes as much as a 15% difference in the chance of dying from COVID-19 for a person who has spent decades living in a county with more pollution.
These findings confirm other studies, such as a 2003 study that found that SARS patients in some of the worst polluted locations in China were twice as likely to die as those in less polluted environments.3
Northern Italy: COVID-19 Growth Rates Approach that of Measles
Meanwhile, a study in Italy has compared the spread of coronavirus in the north, where growth has been rapid, with the south, where it has been much slower. Northern Italy contains most of the country’s industrial areas, as well as higher traffic volumes.
In this study, the authors found that pollution, including fugitive dust particles, can affect coronavirus’ spread.
Normally, when an infected person breathes, talks, laughs, coughs or sneezes, a range of different sizes of droplets containing the virus is expelled. Many of these droplets are larger (10 microns and up) and will drop to the ground fairly quickly, due to gravity. This is the usual way the virus is spread: through direct contact with those droplets, either because you are standing within 6 feet of the person or because you touched a surface that still has those droplets.
However, most of the particles are smaller, under 5 microns in size. These smaller droplets, referred to as “aerosols,” are buoyant, allowing them to stay in the air longer. They can spread up to 27 feet through the air. While not as common as direct contact, this airborne method of contracting COVID-19 is a little harder to defend.
During the SARS outbreak in the early 2000s, there was a case of a nurse contracting SARS despite having never come in contact with a SARS patient. And a mysterious SARS outbreak at an apartment complex in Hong Kong that infected over 300 people is believed to have come from airborne particles from the sewer system.4
What does all of this have to do with dust?
Well, it turns out that those airborne droplets are able to attach themselves to dust particles, which affect coronavirus by serving like vehicles to transport droplets further than they would be able to travel otherwise.
In the words of the study authors:
“Long-distance virus transport is favored by high concentration of dusts…. PM could act as a carrier for droplet nuclei [the solid particulate matter within the larger droplets], triggering a boost effect on the spread of the virus. It could be possible to look at the… particulate matter, as a “highway ” for the viral diffusion… in conditions of atmospheric stability and high concentrations of PM, viruses have a high probability of creating clusters with the particles and, by reducing their diffusion coefficient, enhancing their residence time and amount in atmosphere and promoting contagion.”5
The authors’ proposed hypothesis for how particulate matter helps airborne droplets travel further is shown above in the top image in this article.
The result of pollution in the city of Milan (one of the most heavily polluted cities in northern Italy, and in all of Europe) is that the spread of COVID-19 has been much faster than in southern Italy (in particular Rome, which has nearly double the population size as Milan). This growth rate (measured as the number of new cases resulting from a single current case) is comparable to the highest growth rate in China and is “similar to the epidemic transmission by airborne droplets observed for measles.”
What These Studies Mean
One applicable conclusion of these studies is that efforts and medical supplies could be collected around locations with higher pollution rates to try to preempt rapid spread of the virus in those areas.
But another is, if you manage any kind of unpaved road system, laydown yard, open area or material stockpile, effectively reducing dust particles can help affect some of the risk of coronavirus spreading around your facility or community. Proper dust control removes both a common source of significant health risk to people and a potential vehicle for the spread of the virus.
Midwest, the world leader in effective dust control solutions, can help you design a customized, results-centered dust control program. The results we’ve gotten for other businesses, government agencies and communities include an 85% – 95% reduction in dust, with 90% reduction in water usage and a 75% reduction in ongoing maintenance. Our program will save you money, time and hassle while building a stronger, more durable road surface. Visit our Dust Control Overview page to learn the many options we can provide to help mitigate your dust suppressant challenges.
[1] U.S. EPA. 2018b. Data from the 2014 National Emissions Inventory, Version 2. Accessed 04/28/2020. https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-data
[2] Khan, R.K. and Strand, M.A. “Road dust and its effect on human health: a literature review.” Epidemiol Health. 2018; 40: e2018013. Accessed 04/28/2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5968206/
[3] Friedman, L. “New Research Links Air Pollution to Higher Coronavirus Death Rates.” The New York Times. April 7, 2020. Accessed 04/28/20. https://www.nytimes.com/2020/04/07/climate/air-pollution-coronavirus-covid.html
Wu, X., et al. “Exposure to air pollution and COVID-19 mortality in the United States: A nationwide cross-sectional study.” medRxiv 2020.04.05.20054502. Updated: April 24, 2020. Accessed 04/28/20. https://projects.iq.harvard.edu/covid-pm
[4] Morganstern, J. “Aerosols, Droplets and Airborne Spread: Everything you could possibly want to know.” Updated April 22, 2020. Accessed 04/28/20. https://first10em.com/aerosols-droplets-and-airborne-spread/
[5] Setti, L. et al. “The Potential role of Particulate Matter in the Spreading of COVID-19 in Northern Italy: First Evidence-based Research Hypotheses.” medRxiv 2020.04.11.20061713. April 17, 2020. Accessed 04/28/20. https://www.medrxiv.org/content/10.1101/2020.04.11.20061713v1.full.pdf