Ozone both harms the lungs and weakens the immune system

Quang Thinh

According to US experts, exposure to ozone not only causes pore damage but also reduces the number of important immune cells, making the body more susceptible to attack by toxic substances in contaminated air, especially in urban areas.

Although scientists have long known that exposure to ozone, a major component of urban air pollution, is likely to increase the risk of cardiovascular, respiratory and death diseases, but the mechanism of disease The real ozone is still unknown.

Recently, experts from the Medical Center of Duke University, North Carolina, USA, conducted a study of the effects of ozone on innate immune systems, helping to partly respond to the effects of ozone for human health.

Stimulating the process of self-destruction, reducing macrophages

Chemical structure of ozone (O ₃ ) - a major component in urban air pollution, is likely to increase the risk of cardiovascular, respiratory and death.

According to the team, exposure to ozone not only increases lung damage during the body's fight against bacterial toxins, but also speeds up the process of self-destruction (apoptosis) of possible immune cells. the ability to ' digest ' foreign objects and keep the airways clear.

The process of self-destruction is a process of degeneration, aging and gradual destruction of normal cells in the body.

According to experts, 'if mice were exposed to ozone first and then exposed to bacterial endotoxins in the air, they would have reduced the number of macrophages in their lungs. Exposure to ozone in this context stimulates the self-destruction of immune cells' .

The main role of macrophages is to destroy the residue of the cell and capture and kill pathogens. In the lungs, macrophages function to remove necrotic components and dust, helping to prevent cell inflammation.

"Ozone can make the innate immune system become overactive, killing important immune cells ," said Dr. John Hollingsworth, a lung specialist and lead author of this study . makes the lungs more susceptible to attack by external agents, such as toxic chemicals and bacteria '.

In their tests, the team compared and analyzed the differences between two groups of mice: one group breathed in the room air and the other exposed to ozone, to assess the body's reactions. When you have to live in the air when containing ozone at a harmful level.

An urban area is polluted by ozone.
(Photo: Letsgetitright.org)

Hollingsworth said: 'In mice exposed to ozone, the respiratory glands in the lungs must be overactive and the number of inflammatory cells is also higher than that of unexposed mice'.

Furthermore, this study also showed that exposure to ozone reduced the concentration of immune cells circulating in the blood.

Suggest to adjust the threshold of harmful ozone

While policymakers are debating what level of ozone in the air is safe for human breathing, this study shows that ozone not only affects the lungs but also weakens the system. immune.

Experts will continue to study the mechanism of ozone action in killing cells in macrophages in the lungs. They will also focus on the effects of ozone on immune responses.

According to current standards, the harmful threshold of ozone in the air is 85 parts per billion (85 ppb). Any excess for this threshold is harmful to human health. However, many international health organizations, including the American Thoracic Society, proposed lowering the threshold of ozone in the air to 60 ppb.

These organizations have cited studies that show the serious effects of ozone on human health, especially children and individuals with weak resistance to toxic substances in polluted air. .

As the amount of ozone in the air increases, even in a short time, the number of cases of respiratory diseases and daily deaths increases. Ozone is also considered a carcinogen for some animals, as well as a mutant in some bacteria.

Research by Dr. Hollingsworth and colleagues is published in the journal Immunology, October 1, 2007.

Many international health organizations, including the American Thoracic Society, have proposed lowering the threshold of ozone in the air to 60 ppb.(Photo: oldweb.uwp.edu)