Does car pollution cause asthma?
A growing number of scientists now believe that traffic-related air pollution is a cause, not just a trigger, of asthma. Research confirms that traffic pollution plays a role in the development of asthma that goes beyond just triggering symptoms.
This is a huge breakthrough in the understanding of what asthma is and how it can develop, even in those who aren’t predisposed to the condition. While many factors are involved in a person’s development of asthma, traffic pollution is perhaps one of the most alarming. But now, with recent advancements in portable air purification, it's also one of the most avoidable.
What is asthma?
Asthma is a chronic lung disease that inflames and narrows the airways in the lungs, according to the National Institutes of Health.1 The most common recurring symptoms include:
- Wheezing. This is a whistling or squeaky sound that occurs during breathing.
- Chest tightness. This often feels like someone is sitting on your chest or squeezing your rib cage.
- Shortness of breath. Some people with asthma say they feel out of breath or can’t get the air out of their lungs.
- Coughing. Asthma-related coughing is typically worse at night or early in the morning.
Episodes of these symptoms are known as asthma attacks. During the attack, the sides of the airways in the lungs swell and the airways shrink. An asthma attack often occurs when someone with asthma is exposed to asthma triggers. Some common triggers are:
- tobacco smoke
- dust mites
- cockroach allergens
- air pollution, especially ultrafine particles in vehicle emissions
What is the exact cause of asthma?
Many triggers of asthma attacks are known, but the exact cause of the disorder itself isn’t known, according to the Mayo Clinic.2 Interaction between genetic and environmental factors is believed to be at work.
Traffic pollution may cause asthma
Several studies released in the last two decades overwhelmingly suggest the role of common traffic pollutants in the development and worsening of asthma:
- In 2000, researchers at the University of California, Davis, found that monkeys exposed to ozone developed asthma after only a few months of exposure.3 Ozone is a central component of traffic-related pollution.
- Researchers at the University of Southern California found in 2012 that at least 8% of cases of childhood asthma in Los Angeles County were attributable to traffic-related pollution.4
- A 2012 study of two heavily polluted California cities, Riverside and Long Beach, found that a conservative estimate of the total medical costs incurred by asthma symptoms was about $18,000,000 a year.5
- In 2013, the Swiss Tropical and Public Health Institute reported in the European Respiratory Journal that 14% of asthma cases they studied were attributable to traffic-related pollution. According to the Institute, traffic pollution is statistically comparable to secondhand smoke as a cause of asthma.6
- Middle-aged adults in Tasmania living less than 200 meters from a major road were found to have an increased risk of developing persistent asthma, according to a 2018 study published in Environment International.7
- 2019 study results published in the International Journal of Transportation Science and Technology suggest that between 7% and 12% of annual childhood asthma cases in Bradford, United Kingdom were directly connected to traffic-related air pollution.8
Reducing exposure to traffic pollution
Exposure to traffic pollution is largely a result of where a person lives, works, or goes to school. Generally, concentrations of airborne pollutants are elevated within 500 feet of a busy roadway. Prevailing winds and other factors can significantly affect where pollutant levels are highest.
And outdoor traffic pollutants aren’t the only culprit of car-related pollutant exposure. According to 2012 findings by Ecology Center, over 275 different types of pollutants can be present in a car at any given time.9 This cocktail of toxic pollutants includes a mixture of outdoor traffic pollution and both chemicals and volatile organic compounds (VOCs) off-gassed from steering wheels, dashboard, and armrests, sometimes at nearly twice the level considered dangerous by the World Health Organization.10
Here’s what you can do to help protect yourself from the effects of traffic pollution at home, at school, at work, and on the road in the thick of vehicle pollution.
Some communities have developed recommendations for new construction near busy roads.
- According to the World Health Organization (WHO), 15 member countries have policies established to keep schools a distance from major roadways.11
- Health authorities in Quebec recommend schools be built at least 500 feet (150 meters) away from busy roads.12
- The Air Resources Board (California) recommends that new housing should be sited at least 500 feet from major roadways.13
- The U.S. Environmental Protection Agency suggests screening for high-traffic roads and highways within a half mile of a prospective school building.14
Those who live near a busy roadway should close windows and doors during peak traffic hours.
Also, consider a high-performance air purifier to remove particulates and other pollutants from the indoor air.
High-performance air filtration can be installed in classrooms and in central HVAC systems in schools. A few states have instituted policies indicating how close a school can be built to major highways or other significant pollution sources:
- California: New school sites must be located at least 500 feet from the edge of a freeway or busy traffic corridor15
- Florida: Site must not adjoin a through highway, if practicable16
- Georgia: Risk/hazard analysis required if a site is within 3 miles of a major highway17
A high-performance, ultra-quiet, commercial-grade air purifier is designed to remove particulate matter from classrooms at a high rate, delivering up to 600 cubic feet per minute (CFM) while operating at an extremely low noise level. Call (866) 500-4090 to talk to a Solutions Engineer about custom solutions for school air quality issues.
Air pollution from traffic and other sources can be controlled in the workplace through ventilation, source control, and air filtration.
Those who work in buildings with poor or unpredictable indoor air quality should consider purchasing a high-performance personal air purifier for their work areas.
In Your Car
Driving on congested roadways exposes drivers to a plethora of both particulate and chemical pollutants at extremely high levels and for long periods of time.
Commuters should consider purchasing a high-performance car air purifier to constantly recirculate fresh air throughout the vehicle. Commuters should avoid dangerous ionizers (which can actually make asthma or other respiratory symptoms worse) or ineffective portable air purifiers with little filtration surface area to capture airborne particles and no media to capture chemicals or VOCs.18,19
Air pollution from traffic is a health risk that will not go away anytime soon. Take precautions anywhere you or your loved ones are exposed, including home, work, school, and in your own vehicle.
You may not be able to control air pollution from traffic, but you can control the indoor air you breathe. This includes the air in your car, where you’re most at risk of exposure to dangerous traffic and vehicle pollutants.
IQAir is a Swiss-based air quality technology company empowering individuals, organizations and communities to breathe clean air through information and collaboration. Since its founding in 1963, IQAir has been a global leader and operates in more than 100 countries worldwide.
- Article Resources
 Centers for Disease Control and Prevention. (2020). Asthma.
 Mayo Clinic Staff. (2018). Asthma.
 Fell A. (2000). Primate research shows link between ozone pollution, asthma. UC Davis Health.
 Perez L, et al. (2012). Near-roadway pollution and childhood asthma: Implications for developing “win-win” compact urban development and clean vehicle strategies. DOI: 10.1289/ehp.1104785
 Brandt SJ, et al. (2012). Costs of childhood asthma due to traffic-related pollution in two California communities.
 Ecology Center. (2012). Dangers lurk behind that ‘new-car smell’.
 Gowatte G, et al. (2018). Traffic related air pollution and development and persistence of asthma and low lung function.
 Khreis H, et al. (2019). Traffic-related air pollution and the local burden of childhood asthma in Bradford, UK.
 Müller D, et al. (2011). Car indoor air pollution – analysis of potential sources.
 Perez L, et al. (2013). Chronic burden of near-roadway traffic pollution in 10 European cities (APHEKOM network).
 World Health Organization. (2015). School environment: Policies and current status.
 Rocha R, et al. (2014, Sept. 17). One-sixth of schools in Montreal dangerously close to polluted roads: analysis. Canadian Broadcasting Corporation.
 Environmental Protection Agency, United States. (2015). Environmental siting criteria considerations
 California Air Resources Board. (2005). Air quality and land use handbook: A community health perspective.
 California Charter Schools Association. (n.d.). Planning and permitting the construction and development of facilities for charter schools in California.
 Florida Legislature. (2020). Education facilities.
 Georgia Department of Education Facilities Services Unit. (2012). Guideline for risk hazard assessment of educational facility sites.
 Ozone generators that are sold as air cleaners. Environmental Protection Agency, U.S. (2018). Ozone generators that are sold as air cleaners.
 Li JTC. (2016). Ozone air purifiers: Can they improve asthma symptoms? Mayo Clinic.