Long-term exposure to air pollution increases COVID-19 risk, making those who live in heavily polluted neighborhoods more likely to face severe disease outcomes, a new study finds.
Researchers found that small increases in long-term exposure were associated with three times higher odds of being placed on a ventilator – and double the odds of a stay in an intensive care unit.
The data, from patients from a hospital system in Detroit, Michigan, showed that COVID-19 patients requiring intensive care and ventilators were more likely to live in neighborhoods with higher pollution levels.
This research suggests that pollution may be one reason why communities of color are at a higher risk from Covid in the U.S.
Exposure to PM2.5 pollution was the highest risk factor for ICU admission among these patients, making them 3.5 times more likely to require intensive care
Air pollution is well-known to be a Covid risk factor. And one type of pollution called particulate matter 2.5 (PM2.5) is especially dangerous.
PM2.5 refers to small particles, less than 2.5 micrometers in diameter which is about one ten-thousandth of an inch.
The particles can include dust, soot, metals, and other chemicals. This type of pollution is linked to burning fossil fuels and is released from car engines and factories.
PM2.5 can stress out the respiratory system, especially when people are exposed to this pollution over a long period of time – in other words, if people live in a neighborhood with high pollution levels.
This type of long-term exposure can lead to lung disease, asthma, increased risk of death from the flu, and other respiratory conditions.
It also makes people more vulnerable to severe Covid.
Some researchers have suggested that these small pollution particles may even act as a carrier for the coronavirus, helping it spread faster in polluted areas.
In one 2020 study, Harvard researchers found that higher exposure to PM2.5 particles contributes to higher Covid death rates at the county level.
The new study from physicians in Detroit, Michigan provides more information on the dangers of PM2.5 pollution.
It has not yet been submitted for publication to a scientific paper, meaning other scientists have yet to review the work.
The researchers analyzed data on about 2,000 patients in the Henry Ford Health System, a large hospital system in Detroit.
The patients were hospitalized with COVID-19 in March and April 2020 and looked at their disease outcomes and environmental factors associated with the patients’ ZIP codes.
Detroit, as a city known for its longtime role in the automobile industry, has high levels of air pollution.
The city ranks number 12 on a list of cities with the highest PM2.5 pollution, ranked by the American Lung Association.
Detroit residents living in areas with high pollution levels are more vulnerable to severe Covid. Pictured: A Detroit resident gets vaccinated at a mobile clinic in June 2021
The researchers found that patients living in areas with high PM2.5 levels were more likely to require intensive care or a ventilator, indicating more severe COVID-19.
In fact, patients’ likelihood of requiring intensive care increased by 3.5 times for every small increase in PM2.5 exposure (one µg/m3).
Patients’ likelihood of requiring a ventilator increased by 2.5 times for every small increase in PM2.5 exposure.
Patients who required intensive care and ventilation were also more likely to be male, black, and to suffer from other Covid risk factors, such as obesity.
The researchers additionally found that patients living in areas with high traffic and polluted wastewater were more likely to die at the hospital.
‘Our study calls attention to the systemic inequalities that may have led to the stark differences in COVID-19 outcomes along racial and ethnic lines,’ said Dr Anita Shallal, physician at Henry Ford Hospital and lead author on the study.
‘Communities of color are more likely to be located in areas closer to industrial pollution, and to work in businesses that expose them to air pollution.’
These communities also tend to have lower life expectancies and higher rates of chronic conditions such as diabetes and obesity.
Historians tie such negative outcomes to redlining, housing discrimination practices in the early 1900s century that separated black and white neighborhoods.
‘Urgent further research is needed to guide policy and environmental protection, to minimize the impact of COVID-19 in highly industrialized communities that are home to our most vulnerable residents,’ Shallal said.
The study was presented on Thursday at the European Congress of Clinical Microbiology & Infectious Diseases.