The Connections Between Air Pollution and Asthma

It is widely recognized that air pollution exposure has various health effects. 

People living in developing and overpopulated countries like India disproportionately experience the burden of outdoor air pollution. As well as causing new cases of asthma, air pollution can exacerbate the symptoms of people with existing lung conditions. This page contains all the information that you need to know about the link between Air Pollution and Asthma. 

What Is Asthma?

Asthma is a serious, chronic respiratory disease in which the airways narrow due to inflammation, making breathing more difficult. Symptoms, such as coughing, with or without mucus, wheezing, chest tightness, and shortness of breath, and their frequency differs depending on the person and can change over time. 

Many factors trigger symptoms, including viral infections, exercise, pollen, and air pollution.

What Is Air Pollution?

Air pollution is an umbrella term for chemicals and particles which contaminant the atmosphere. It is the contamination of the air with a complex mixture of substances that harm human health and the environment. Air pollution can harm people’s health, especially for children whose lungs and immune systems are still developing and aged people, making them more susceptible to its harmful effects. Air pollution can harm you even if you can’t see it or smell it.

Air pollution and asthma statistics: The data from the World Health Organization (WHO) indicate that 9 out of 10 people breathe air containing high levels of pollutants. More than 80% of people living in urban areas, where air pollution is monitored, are exposed to air pollutant levels that exceed WHO guideline limits.

Key Air Pollutants That Trigger Asthma

Outdoor air pollution includes both primary pollutants emitted directly into the atmosphere and secondary pollutants formed in the air from the chemical transformation of the primary pollutants. 

The main causes of air pollution are nitrogen dioxide from motor vehicles and fine particulate matter (PM2.5), tiny particles of pollution that come from domestic wood and coal fires, cars, and

windblown dust. 

• Particulate matter, nitrogen dioxide, ozone, and sulphur dioxide are particularly damaging types of air pollution. Motor vehicles, power plants, chemical plants, refineries, factories, and gas stations are just some of the sources that generate these dangerous pollutants. 
• Ground-level ozone (smog) is formed when nitrogen oxides, volatile organic compounds (VOCs), and sunlight mix. 

Particulate matter, especially fine particles known as PM2.5, can penetrate deep into the lungs

and even enter the bloodstream, causing chronic health effects. Each of these pollutants alone or in combination can cause respiratory distress.

How Air Pollution Affects the Lungs

Air pollution harms everyone’s lungs, but it’s especially harmful if you have a lung condition like asthma. 

Air pollution contains harmful substances that can be toxic to the respiratory tract. Air pollution irritates the lungs and respiratory system and can even affect the heart. Air pollution can make asthma worse, trigger asthma attacks, or cause the onset of asthma.

Air pollutants are suspected to contribute to asthma symptoms in different ways. 

• Larger particles can physically obstruct and aggravate airways at the bronchiole level, while smaller particles (PM2.5 and PM < 2.5) are able to enter the bloodstream across the lung alveoli and can trigger an inflammatory cascade resulting in acute bronchospasm.
• Air pollution also causes oxidative stress in the respiratory system, increased inflammation pathways, and enhances respiratory sensitization to allergens.

The Link Between Air Pollution and Asthma

Being exposed to air pollution over a long period of time can cause lung conditions, including asthma and chronic obstructive pulmonary disease (COPD). 

Air pollution harms everybody, but it’s especially harmful if you have asthma. In around two-thirds of people with asthma, poor air quality makes their asthma worse, putting them at risk of an asthma attack. 

Air pollution can irritate your airways. It can also make your asthma symptoms, such as coughing, wheezing, breathlessness, and chest tightness, worse.

Research studies on Air Pollution and Asthma have shown that exposure (even short-term) to outdoor air pollutants affects asthma outcomes in the following ways:

• Poor asthma control
• Decreased or impaired lung function
• Increased consumption and requirement of asthma medications 
• Higher asthma exacerbations
• More emergency hospital visits, hospitalizations, and deaths 
• Worse quality of life

Impact of Air Pollution on Children with Asthma

Exposure to air pollution early in life contributes to the development of asthma throughout childhood and adolescence, particularly after age 4 years. Higher exposure to fine particulate matter, nitrogen dioxide, and ground-level ozone was associated with increased asthma incidence in children up to age 10. Air pollution exposure is thought to potentially cause asthma in children by impacting the developing lung and immune system.

Compared to adults, the impact of air pollution in children is considered greater for several reasons: 

1. smaller airway diameter leading to higher chances for airway blockage from larger particulate matter (PM)
2. The length of time in playgrounds and outdoor activities is likely to be greater
3. Increased respiratory rate and preferential mouth breathing result in greater inhalation and deposition of pollutants
4. developing lungs are more sensitive 

What research says about air pollution and childhood asthma: Air pollution has been associated with recurrent respiratory infections, reduced lung function in childhood, and a higher frequency of childhood asthma following exposure in early infancy. 

Air Pollution and Adult-Onset Asthma

Pollution can trigger asthma in individuals with no previous history of the disease due to a number of determinants, such as genetics or changes in the immune system as a result of exposure to pollutants. This leads to adult-onset asthma.

Age is a risk factor for developing adult-onset asthma, as reflected by a higher prevalence and number of hospitalizations for asthma in older adults.

What research says: Research studies show that air pollution increases the risk of adult-onset asthma, but this risk also depends on lifestyle and genetics. 

Symptoms of Pollution-Induced Asthma Worsening

Look out for the following symptoms and signs that indicate that your asthma is being worsened by air pollution:

• coughing 
• difficulty with breathing
• more breathlessness when doing an activity outdoors
• wheezing
• irritation in your nose and throat
• pain when taking a breath
• asthma attacks or COPD flare-ups 
• needing to use your reliever inhaler more often.

How to Protect Yourself from Air Pollution If You Have Asthma

Use the following indoor and outdoor strategies to protect yourself from the effects of air pollution:

1. While indoors, air cleaners and high-efficiency particulate air (HEPA) filters can help reduce asthma triggers. 
2. Limit outdoor activities and exercise. If you have to go outdoors, go out earlier in the day when air quality tends to be better. 
3. Avoid areas where there’s a lot of traffic and factories/ industrial buildings.
4. Keep your car windows closed if you’re driving, especially if you’re driving in slow-moving traffic.
5. Avoiding smoke or vape emissions both in and outdoors and using fragrance-free cleaning products are some other ways that you can keep asthma from worsening symptoms.

Role of Medical Management in Pollution-Related Asthma

All asthmatic patients must have a controller asthma treatment prescribed by a qualified doctor or pulmonologist. This should include

• Inhaled corticosteroids (ICSs) decrease adverse responses to pollutant exposures
• Combination therapy with ICS and long-acting beta-agonist (LABA) for asthmatic smokers
• Montelukast (leukotriene receptor antagonist) represents another therapeutic option as a controller of asthma. 
• Dietary supplements such as carotenoids, vitamin D, and vitamin E, which protect against airway inflammation and damage induced by pollutants that can trigger asthma initiation

Lifestyle Changes to Reduce Pollution Impact

• Smoking cessation must be encouraged in all possible ways to reduce the exposure of people with asthma. Smoking cessation in patients with asthma leads to better symptom control, less use of rescue medication, improved asthma quality of life score, lung function
• Improving household ventilation by opening windows or doors, using chimneys, hoods, or exhaust fans

Conclusion

Air pollution exposure has various health effects, especially on the respiratory system. There is a strong link between air pollution and asthma. Contamination of the air with pollutants can harm people’s health, especially for children and elderly people. Being exposed to air pollution over a long period of time can cause lung conditions, including asthma. Medical management and lifestyle changes are the key treatments for those with pollution-related asthma. 

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