Pollution and Pandemics: A Dangerous Mixture
According to research in the Chakrabarty lab, as one goes the other goes to a point.
The United States may have been prepared to spread a pandemic without even knowing it.
According to new research from the McKelvey School of Engineering at Washington University in St. Louis, pollution may be partly to blame for the rapid proliferation in the United States. SARS-CoV-2, the virus responsible for the spread COVID-19.
The research, in the laboratory of Rajan Chakrabarty, an associate professor in the Department of Energy, Environmental and Chemical Engineering, was published online before being printed in the journal. The science of the whole environment.
When someone becomes ill after hiring COVID-19, medical professionals believe that a person’s health (e.g., having certain health conditions) may play a key role. By knowing how the virus can spread throughout the community, the health of the environment is related to the basic reproductive ratio R.0, which indicates the expected amount that each patient can infect.
Reproductive ratio R0 COVID-19 directly links long-term atmosphere to PM2.5 exposure levels. And the presence of secondary inorganic components in PM2.5 it makes things worse, according to Chakrabarty.
“We checked more than 40 confounding factors,” Chakrabarty said. Among all these factors, “there was a strong, linear link between long-term PM2.5 exposure and R0“.
AFTERNOON2.5 Refers to surrounding particles with a diameter of 2.5 micrometers or less; at this size, they can enter a person’s lungs and cause damage. Therefore, PM2.5 can be detrimental to respiratory health. But what it has to do with the spread of COVID-19 through the population has not been studied.
Chakrabarty and his graduate student Payton Beeler, aerosol researchers who have done previous coronavirus modeling, became interested in the relationship after two consecutive articles were published. First, the July paper in the magazine Science found that the level of sensitivity to COVID-19 is the main cause of the pandemic; it is more important than temperature, as researchers initially thought it could play an excessive role.
In August, a study published in the journal Journal of Infection they found that most cases of severe COVID-19 disease occurred in places with higher levels of contamination.
“I was thinking, why have we had the virus spread so fast in most US states?” Chakrabarty said. Especially in the early stages of the pandemic. “We wanted to limit our study stop to the time it was in effect. Most of the time it was closed from the beginning of March to the end of April. “
The team decided to study R’s locations0 it was bigger than one – that’s what a person can spread the disease to more than one and get rid of the disease. In these places, 43 different factors were examined – population density, age distribution, as well as time delays in requests to stay at home in the states.
Then, Randall Martin, a professor published in the Department of Energy, Environmental, and Chemical Engineering, used the U.S. to calculate the relationship between 2012 and 2017 using pollution estimates.
Modeling has shown growth of almost 0.25 years R0 corresponding to a 10% increase in sulfate, nitrogen dioxide and ammonium or SNA composition and an increase of 1 μg / m.3 PM-n2.5 mass concentrations, respectively.
These linear correlations have been found to be strongest in areas where the level of pollution was below national ambient air quality standards (NAAQS), at levels of air pollutants considered safe for humans.
“The average annual PM2.5 national standards are set at 12 micrograms or less per cubic meter, probably below what you will be, ”Chakrabarty said.“ What we’ve seen is that the correlation we’re seeing is below that standard. ”In fact, they saw rapid growth in R0 When PM2.5 the exposure level was below 6 micrograms per cubic meter.
Chakrabarty assumes this initial increase in R0, after which there is a plateau, after reaching 6 micrograms per cubic level, as a result of changes in the initial state. when the air has no PM2.5, does not affect an individual. Initial exposure is a catalyst for change in lung health, ranging from insensitivity to sensitivity.0.
And although there was no direct correlation between black carbon – even soot – and R0, the researchers found the link.
“Our collaborators at the University of Saint Louis suggested a statistical approach to mediation / moderation,” a detailed study examining the impact of additional variables on the outcome of the initial relationship. In this case, the researchers studied the effect of soot on Rn0, Considering the effect of SNA.
“We have found that carbon blacks are a kind of catalyst. When there is soot, PM2.5 has a greater effect on lung health and therefore Rn0“.
The mediation / moderation study was not in vain: one of the most common ways people approach the SNA is pollution emitted by cars and coal-fired power plants. They both emit soot.
“Although stringent air quality regulations in the United States have significantly reduced nitrogen dioxide levels over the decades,” the authors wrote in the paper, “the recent reversal of environmental regulations that undermine the limits of power plants and vehicle emissions is a future scenario for air quality.”
“Instead of working to solve this problem, these setbacks will set us up for another pandemic,” Chakrabarty said.
Reference: “Ambient PM2.5 COVID-19 Exposure and Rapid Expansion in the United States by Rajan K. Chakrabarty, Payton Beeler, Pai Liu, Spondita Goswami, Richard D. Harvey, Shamsh Pervez, Aaronvan Donkelaar, and Randall V. Martin on November 9, 2020, The science of the whole environment.
DOI: 10.1016 / j.scitotenv.2020.143391
The authors have made their data and source codes public.