Severe Cases Of Covid-19 Linked To Long-Term Air Pollution Exposure

New research found a link between long-term exposure to nitrogen dioxide (NO2) and cases of severe Covid-19 that require ICU care and mechanical ventilation. 

Embed from Getty Images

According to a study conducted in 2020 using healthcare data from 4,443 fatal cases of Covid-19, long-term exposure to high levels of nitrogen dioxide (NO2) correlated to an increased risk of severe/potentially fatal cases of Covid-19. 

NO2 is a pollutant gas that’s released when burning fossil fuels, most commonly during traffic. Long-term exposure to NO2 in general is known to cause health problems, and is linked to an increased risk of cardiovascular and respiratory-related death. 

Recently, researchers investigated the impact of long-term NO2 exposure and its connection to Covid-19 patients who needed to be treated in the ICU with mechanical ventilation treatment. The study concluded that there was a link between long-term NO2 exposure and an increased need for ICU care and mechanical ventilation, according to Medical News Today, which reported on the study’s findings. 

“Knowing how long-term nitrogen dioxide exposure impacts COVID-19 outcomes could help policymakers better allocate resources to treat the condition.”

The researchers presented their findings at the Euroanaesthesia Congress in Milan, Italy. They explained that they gathered air pollution data from 2010 to 2019 for 392 of Germany’s 402 counties for the study. 

They calculated the long-term average levels of NO2 in the atmosphere while simultaneously gathering data on the number of occupied ICU beds and the need for mechanical ventilation from the German Interdisciplinary Association for Intensive Care and Emergency Medicine registry from April 16, 2020, to May 16, 2020, which is when officials lifted lockdown restrictions.

Using this data, they then had to analyze and adjust their findings to account for population density, age, socioeconomic factors, and other pre-existing health conditions or factors that may affect the severity of Covid-19. Dr. Tia Babu was not involved in the study, but is the Acting Assistant professor in the Division of Allergy and Infectious Diseases at the University of Washington, who spoke on the study’s findings, and why they make sense. 

Embed from Getty Images

“Nitrogen dioxide exposure is associated with a myriad of effects to the lungs, including lung injury, decreased lung function, and inflammation. Perhaps the chronic exposure to nitrogen dioxide leads to decreased pulmonary function or an abnormal local lung immune response to the Covid virus.”

Embed from Getty Images

Dr. Fady Youssef, a board certified pulmonologist, said that “pollutants can promote a proinflammatory state in the lungs that can have an additive effect on inflammation triggered by Covid-19. 

Dr. Susanne Koch, the lead author of the study, gave a more in depth explanation of why it makes sense that increased exposure to pollutants could impact the severity of Covid-19 in an individual. 

“[A protein called] ACE-2 helps ‘put the brakes’ on inflammation, but exposure to air pollutants triggers inflammation or ‘releases the brakes.’ And again, when the SARS-CoV-2 virus binds to ACE-2, these brakes are removed, which leads to an additive effect, more severe inflammation and a more severe course in COVID-19.”

“There are many other variables that can be associated with environments where NO2 levels are elevated that could be responsible for the correlation, [although] the study did control for some of them,” Dr. Youssef added.

Dr. Koch then explained what this study specifically means in terms of the environment: “While the COVID-19 pandemic may end by reaching herd immunity through infection or vaccination, exposure to ambient air pollution will continue to affect people’s health. The only remedy is reducing emissions.”

“The transition to renewable energy, clean transportation, and sustainable agriculture is urgently needed to improve air quality, which will also help mitigate climate change, to improve population health and quality of life around the world.”