Air pollution is worsening emphysema

Executive Summary

Emphysema is a serious, irreversible lung disease. Smoking is the leading cause of it. However, outdoor air pollution, especially ozone, is also found to cause and worsen emphysema, and reduce lung function.

Air pollution is the new smoking.

Emphysema is a lung condition that involves shortness of breath. Smoking is a leading cause of emphysema. However, new research shows that various common pollutants in air are significantly associated with increasing emphysema.

Emphysema

Inside our lungs, there are air sacs (alveoli) where oxygen is exchanged with carbon dioxide from blood. However, over time, in people with emphysema, the inner walls of the alveoli weaken and rupture. This reduces the total surface area of the lungs.

As a result of alveolar damage, the person is not able to exhale the old air — high in carbon dioxide — properly. In such people, sufficient oxygen does not reach their blood. So, they are always short of breath.

Chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is a serious lung disease. There are two types of COPD: emphysema and chronic bronchitis.

Chronic bronchitis is the persistent inflammation of the airways in the lung. This can cause a persistent cough. Most patients of emphysema also have chronic bronchitis.

In COPD, the lung tissue gets damaged and dies. This reduces the amount of oxygen available to the body. COPD causes coughing, wheezing, shortness of breath, chest tightness, and other symptoms. Over years, COPD can lead to death.

COPD is irreversible. Treatment, at best, may slow down the progression of COPD.

Smoking is the leading cause of COPD. However, 25% of people who develop emphysema have never smoked. So, researchers were baffled about the cause of COPD in such patients.

New research

Scientists at the University of Washington and Columbia University studied 5,800 patients in 6 large cities in the USA.

They measured outdoor pollution levels where these people lived. They also measured emphysema levels of the patients using CT imaging and lung function tests. The patients were followed for a median of 10 years.

Results

The results were published in Aug 2019 in the Journal of American Medical Association. Here are some findings:

• Higher outdoor concentrations of the pollutants ozone (O₃), fine particulate matter (PM_2.5), and various oxides of nitrogen (NO_x) at a person’s residence at the beginning of the study were associated with increases in emphysema over the following 10 years.
• Higher levels of ozone and NO_x at homes were also associated with faster progression of emphysema.
• Ozone exposures posed the greatest risk.
• Ozone was also associated with declines in air flow in the lungs.
• These associations were seen regardless of participants’ age, gender, race, ethnicity, socioeconomic status, and whether the person smoked. In other words, the prevalence of emphysema was purely a function of air pollution, and did not depend on the person and his background.

Thus, the bad effects of air pollution appear to be just like those of smoking cigarettes. Read on this website: how many cigarettes will you smoke today? This article calculates what levels of air pollution are equivalent to smoking a cigarette a day.

Actionable tips

1. If you live in a polluted area, consider shifting to a less polluted city.
   Consider, especially, if there are young children in the household.
2. When indoors or traveling in a car, stay in controlled air with reduced pollutants.
   Consider using an air purifier that cleanses air of the common chemical pollutant gases.

First published on: 22nd September, 2019

Image by kalhh from Pixabay