Smog in the big city: epidemiologist named a new reason for the spread of coronavirus

It turns out that the spread and course of coronavirus infection is influenced by the level of air pollution. Kizkhalum Khametova, a researcher of the laboratory of means of specific prevention of viral diseases at the Gamaley National Research Center for Epidemiology and Microbiology, told about it during the TASS online conference. Kizkhalum Khametova told TASS during an online conference.

How does polluted air “help” coronavirus?

The air in large cities is often more polluted than in small towns. Therefore, residents of megacities are more prone to chronic diseases of the cardiovascular and respiratory systems. According to WHO statistics, 4.2 million people die annually in the world because of polluted atmosphere.

According to the expert, those affected by urban smog are more vulnerable to the coronavirus, and their disease tends to be more severe – the virus exacerbates chronic problems that a person already has.

“Many researchers around the world have now found a direct link between environmental changes and the spread of dangerous viruses. This is especially true now, during the spread of the new coronavirus infection,” said the epidemiologist at a press conference dedicated to the presentation of the study “Improving the environmental friendliness of the transportation sector in the world’s megacities.”

But this is not the only thing that can cause COVID-19 disease. According to the researcher, polluted air in general weakens the immune system, making it harder for the body to fight infections.

How does air pollution affect immunity?

Researchers from Stanford University and the University of California at Berkeley found that exposure to polluted air suppresses regulatory T cells in the immune system. Reduced functioning explains the greater severity of asthma symptoms and also reduces lung capacity. When T-cell function is low, they cannot block inflammation.

To confirm the theory, scientists analyzed the health of 40 children from the city of Fresno, where the air is very polluted, and 40 children from Palo Alto, where the level of pollution is less. Half of them had asthma. The children were matched for age, sex and asthma status and tested for respiratory function, allergy sensitivity and T-cells in the blood.

The researchers calculated each child’s average annual exposure to polycyclic aromatic hydrocarbons (PAHs), a byproduct of fossil fuels and a major pollutant in car exhaust. It turns out that Fresno children’s exposure to PAHs is 7 times greater than Palo Alto children. Ozone and particulate matter in the air were also significantly higher in Fresno. Not surprisingly, children from that city were noted to have lower levels of T-cell function and more severe asthma symptoms.

“There are people who still doubt the direct link between air pollution and human health, but our results make it impossible to deny the irreparable health effects of air pollutants,” notes study author Ira Tager, a professor of epidemiology at the UC Berkeley School of Public Health.

The immune system suffers most of all from polluted air. Because of what can aggravate diseases of the lungs and cardiovascular system, and the body becomes more vulnerable to infections. Therefore, residents of megacities should pay special attention to their own health and do not neglect epidemiological safety measures.