Understanding the Strong Link between Air Pollution and Asthma​

Air pollution is a threat to public health, especially for children whose lungs and immune systems are still developing, making them more susceptible to its harmful effects. Though there are many health issues linked to air pollution, childhood asthma stands out as a significant concern. This chronic respiratory condition has a harmful effect on the quality of life of over 4.7 million children nationwide. Considered one of the most common chronic childhood diseases, studies have found that asthma related episodes cause approximately 13.8 million missed school days a year, impacting academic performance and well-being. Air pollution is a top trigger, leading to worsening asthma symptoms and severe health concerns.

Understanding Air Pollution

Air pollution is the contamination of the air with a complex mixture of substances that harm human health and the environment. The U.S. Environmental Protection Agency (EPA) identifies six widespread pollutants that are particularly harmful, including particulate matter (PM), ozone (O₃), carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and lead.

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 is formed when nitrogen oxides, volatile organic compounds (VOCs), and sunlight mix. Ground-level ozone is also called smog. 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.

Exposure to air pollution has both short-term and long-term health effects. Respiratory infections and asthma or chronic obstructive pulmonary disease (COPD) symptoms that may lead to a flare-up are considered short-term consequences. But in the long-term, air pollution can cause cardiovascular diseases, stroke, lung cancer and other chronic diseases. Unfortunately, nearly half the U.S. population lives in areas with unhealthy levels of air pollutants. And, according to the World Health Organization, air pollution is responsible for approximately 6.7 million premature deaths annually.

Childhood Asthma and Air Pollution

Children are particularly affected due to their higher breathing rates and developing organs. They also commonly spend more time outdoors, increasing their exposure to pollutants. One study found that that exposure to PM_2.5 and NO₂ during early childhood (the first three years) increases a child’s risk of developing asthma. Additional research suggests that prenatal exposure to polluted air increases the risk of asthma development in the child. Risk of asthma development was also twice as likely among Black children and those from socioeconomically disadvantaged backgrounds because they are more likely to live near pollution sources such as highways or manufacturing and have less access to healthcare.

For children already diagnosed with asthma, air pollution is a known irritant and trigger for symptoms such as wheezing, coughing and shortness of breath. Increased exposure to particle pollution and ground-level ozone have been found to cause reduced lung function, higher emergency department visit rates and more frequent hospitalizations.

Air Pollution at Home

Indoor air pollution can significantly impact children with asthma, as their developing lungs are more sensitive to irritants. Common indoor triggers include tobacco, wood smoke, mold spores, pet dander, and dust mites, which are often found in carpets, bedding, and upholstery. Household cleaning products, air fresheners and paints can also release volatile organic compounds (VOCs) that irritate the airways. Poor ventilation can worsen the buildup of these pollutants, making enclosed spaces more hazardous. Additionally, gas stoves and heaters that are not properly ventilated can emit nitrogen dioxide, benzene, and carbon monoxide, all of which can trigger asthma and cause other health issues.

Reducing the Risk of Asthma Flare-Ups Due to Air Pollution

There are a few steps you can take to protect your child or yourself from asthma flare-ups caused by pollution. Parents should check the daily air quality status and stay indoors on high-pollution days. While indoors, air cleaners and high-efficiency particulate air (HEPA) filters can help reduce asthma triggers. 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.

What Can You Do?

The link between air pollution and childhood asthma is clear and deeply concerning. As air quality continues to decline in many regions, the health and well-being of children are increasingly at risk. Encouraging urban greening, the use of zero-emissions vehicles and advocating for cleaner energy sources are just a few things that can make long-term improvements in air quality and protect children with asthma. But policymakers, healthcare providers, and communities must work together to combat this threat and safeguard the health of future generations. Find out about the air pollution in your community through our State of the Air report and learn more about how to better manage your child’s asthma with our guide for parents.