Pollution and the Pandemic

The unique conditions created by the novel coronavirus pandemic has led to interesting developments among researchers regarding pollution.

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1. As it is unlikely that conditions, such as reduced traffic and a sudden decrease in noise and light pollution, created by the pandemic will be replicated, the research generated is critical to new and unique developments regarding pollution.

When the first lockdowns occurred in March, there was a noticeable decrease in pollution. This change was especially noticeable around metropolitan areas, where there was a sharp reduction in commuter traffic. Smog, light, and auditory pollution all decreased. Beyond improving the quality of life for animals, the sudden drop in pollution offered insight into a plethora of topics regarding the contaminants in our natural environment.

Researchers took a nuanced approach to analyzing the changes in pollution, for example comparing current pollutant levels to past ones to determine the severity of the pandemic’s effect. Because of factors including current pollution reduction efforts and natural disasters like the Californian wildfires, researchers and analysts observed notable changes through careful analysis of pollutant levels, and accounted for them while developing a complex analysis of the atmosphere. Though they ordinarily account for these events, the coronavirus pandemic was anything but normal.

This posed a major obstacle: a modern pandemic had never happened before, so pre-existing models of the atmosphere were extremely limited. To remedy this, Christoph Keller of the Universities Space Research Association at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and his team completely disregarded the pandemic. When creating models of the weather and pollution, they neglected all predictable outcomes of the pandemic. They avoided reprogramming pre-existing models and observed only the pandemic's effects on pollution, specifically nitrogen dioxide through simple subtraction. This strategy allowed them to receive data from 46 countries and compare the change in emissions as a result of the pandemic.

The data was both surprising and expected by the researchers, as nitrogen dioxide levels decreased significantly. “In some ways, I was surprised by how much it dropped. Many countries have already done a very good job in lowering their nitrogen dioxide concentrations over the last decades due to clean air regulations, but what our results clearly show is that there is still a significant human behavior-driven contribution," Keller said. Though this trend was previously established by countries carrying out reduction efforts, the statistics differed in one distinct way. Whereas these countries experienced "rebound" periods from the nitrogen dioxide levels increasing in response to a decrease, Keller and his team concluded that the rebound period did not occur due to the pandemic. Similar to the decrease of nitrogen dioxide levels, additional research suggested that the amount of PM2.5, or particulate matter with a diameter of less than 2.5 micrometers, had shown a significant reduction during the initial lockdown period.

From this data, researchers can observe and potentially develop new ways of combating high levels of pollution. For example, the absence of a rebound in nitrogen dioxide offered greater insight into avoiding a resurgence of pollutants. Similarly, the pandemic has allowed researchers to observe the efficacy of reduced transportation and human interaction in urban areas. From this, they can also infer whether legislation against pollution caused by high traffic is an effective means of reducing pollution levels. For example, researchers may be able to use this research to exemplify the specific effects of a decrease in traffic; from this, politicians and legislators can infer which policies best decrease traffic, thus reducing pollutants.

Researchers also obtained important information about the links between pollution and immune responses. As an airborne disease, the coronavirus gave scientists unique insights into the role that pollution plays in the spread and degree of severity of respiratory illnesses. Epidemiological estimates indicate that air pollution contributed to 29 percent of coronavirus deaths in the Czech Republic, 27 percent in China, and 26 percent in Germany. According to Professor Thomas Münzel from the University Medical Center of the Johannes Gutenberg University, Germany, the pollutants can cause severe stress on the respiratory and immune systems of those breathing them.

"When people inhale polluted air, the very small polluting particles, the PM2.5, migrate from the lungs to the blood and blood vessels, causing inflammation and severe oxidative stress," Professor Münzel says. Though the link between the spread of respiratory illnesses and pollution is strong, Münzel also notes that the research supporting this link has limitations. For one, the analysis was conducted on middle to high income countries, creating a model that is not necessarily applicable to the entire world. Additionally, the research was developed by analyzing data from individual countries rather than data from individuals, and thus could hide significant variations in different regions and climates. Regardless, the results have given researchers better opportunities to observe the larger health effects of pollution.

Though the environmental and epidemiological findings are preliminary, they open doors to answer several questions about pollution. As it is unlikely that conditions created by the pandemic, such as reduced traffic and a sudden decrease in noise and light pollution, will be replicated in the future, the research is critical to new developments regarding pollution. Specifically, the research completed during the pandemic has allowed analysts to determine the more direct causes and effects of pollution. Whether or not the progress made in research will play a role in decreasing pollutant levels in the future, preventing other pandemics from occurring, or even equipping researchers to deal with future unprecedented conditions, it is sure to send waves through the scientific community.