Bad air quality can contribute to bronchitis, particularly if there is pollution from cigarette smoke. Other pollutants in the environment, such as toxic gases and dust, can also increase the risk.

Bronchitis refers to inflammation of the airways in the lungs. It can cause coughing, usually with mucus production. It may be acute, or short term, but it can become chronic, or long term. Chronic bronchitis is a type of chronic obstructive pulmonary disease (COPD).

This article explores how bad air quality can cause or worsen bronchitis, as well as the types of pollutants that could contribute and whether they can cause infections. It also discusses whether other environmental factors can cause bronchitis and offers tips for improving air quality indoors.

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According to a 2021 study, which is the largest to date on the topic, there is a link between air pollution and chronic bronchitis.

While the study found associations between many pollutants and the prevalence of mucus and a cough, it discovered a significant link between nitrogen dioxide, black carbon, and these symptoms.

Both nitrogen dioxide and black carbon are byproducts of burning fossil fuels and come from sources such as car engines and burning coal.

The authors of the study concluded that exposure to these substances increased both the incidence and prevalence of chronic bronchitis. Incidence refers to the number of new cases in a population during a certain timeframe, while prevalence refers to the total number of cases overall.

The association does not apply to acute bronchitis, which usually occurs due to an infection.

Pollutants with links to chronic bronchitis include:

Cigarette smoke and e-cigarettes

A 2019 review of chronic bronchitis notes that smoking is the most important risk factor for chronic bronchitis, as it has a strong effect. It cited an older 2006 study that found the incidence of chronic bronchitis was 42% in people who currently smoked, 26% in people who used to smoke, and 12% in people who have never smoked.

Passive smoking, or secondhand smoking, can also contribute to chronic bronchitis. This means that inhaling smoke from other people’s cigarettes and tobacco products can also raise the risk.

Emerging evidence suggests that the fumes from vaping nicotine or cannabis also raise the risk of bronchitis-like symptoms in young adults. Research on the long-term effects of vaping and e-cigarettes is ongoing.

Traffic emissions

The 2021 study that found a link between chronic bronchitis and exposure to nitrogen dioxide and black carbon states that local traffic is the main source of these pollutants.

The association between the two pollutants and chronic bronchitis was evident even in low concentrations, meaning traffic fumes have a significant impact on lung health.

Occupational chemicals and gases

A 2019 review of older research indicates that certain occupations involve exposure to chemicals that have a moderate effect on chronic bronchitis risk. Such occupations include:

  • coal and hard-rock mining
  • concrete manufacturing
  • livestock farming
  • work that takes place in tunnels

People in these working environments may breathe in gases from animals, allergens, toxins, and organic dusts.

House dust

A 2018 study found a link between house dust and chronic bronchitis. It measured levels of endotoxin — a substance from certain bacteria that is everywhere in the environment — from bedding and bedroom floors.

The results indicated that exposure to endotoxin in house dust linked to a higher risk of chronic bronchitis. This was especially true for people with allergies to substances in the air.

The direct cause of an infection is exposure to a microbe. However, pollution may have a negative effect on the immune system, increasing the risk of lung infections.

An older 2016 review concluded that people with chronic respiratory conditions, such as chronic bronchitis, are particularly susceptible to the effects of air pollution.

Previous research has shown that air pollution can result in exacerbations of COPD, increase respiratory symptoms, and decrease pulmonary function.

Yes, other factors in the home or outdoors can make bronchitis worse.

A 2018 review notes that winter is a challenging time of year for people with chronic respiratory conditions, especially in northern areas. General exposure to cold can worsen chronic bronchitis.

The United States Environmental Protection Agency offers the following tips for improving indoor air quality:

  • Increase ventilation: When weather permits, open windows and doors to allow fresh air inside. Make sure extractor fans are clear of debris and working efficiently.
  • Keep humidity at an optimal level: This ranges from 30–50% humidity. If it is too low, use a humidifier to increase it. If it is too high, open the windows, unless there is high humidity outdoors.
  • Change air filters regularly: These trap dust and other pollutants.
  • Do not smoke: Ask people not to smoke or vape inside the home. If people must smoke or vape, they should go outside.
  • Be careful with household chemicals: Avoid using chemicals with strong fumes wherever possible. When using them, choose nontoxic options where appropriate, and open the windows for adequate ventilation. Never mix household products unless the label directs this.

It is also advisable to regularly dust and clean the home. People with allergies or asthma may benefit from using a vacuum or air purifier with a HEPA filter.

Bad air quality can contribute to bronchitis as a result of pollution. A pollutant with strong links to chronic bronchitis is cigarette smoke, but traffic emissions, certain fumes and chemicals, and dust may all raise the risk.

Air pollution may also have a negative impact on the immune system, increasing the risk of lung infections or acute bronchitis.

Various measures can improve air quality in someone’s immediate environment. Examples include changing air filters regularly and not allowing a person to smoke inside the home.