A study from the McKelvey School of Engineering at Washington University shows that pollution may have contributed to the rapid spread of COVID through the United States.
The spread of COVID is directly associated with the long-term ambient level of PM2.5 (particles less 2.5 micrometres in diameter) and the reproduction number R0 for the coronavirus. PM2.5 are small enough to enter the lungs and cause damage. Matters are only worsened with secondary inorganic components in PM2.5.
Looking at 43 factors such as age, population density and time delays in lockdown orders, and comparing it to pollution statistics, they found a linear association with PM2.5 concentrations and inorganic components. Interestingly, this relationship only appeared above a certain level of air pollution.
“Annual mean PM2.5 national standards are set at or below 12 microgrammes per cubic metre, below that you are supposed to be safe,” said Rajan Chakrabarty, associate professor in the Department of Energy, Environmental & Chemical Engineering. “What we saw, the correlation we’re seeing is well below that standard.”
More detailed analysis showed that black carbon in the form of soot had a synergistic effect. “We found black carbon acts as a kind of catalyst. When there is soot present, PM2.5 has more of an acute effect on lung health, and therefore on R0.”
Source: Science Daily
