Smog from the wildfires, traffic-related air pollution, industrial facilities and factories all contribute to the outdoor air pollution that we breathe. The outdoor ambient pollution comprises of gaseous pollutants (ozone, nitrogen dioxide, and sulfur dioxide) and particulate matter (1). At high levels of air pollution, particles and fumes have a direct irritate airway epithelium (1). Nitrogen dioxide and ozone can induce airway hyperresponsiveness. Particulate matter less than 2.5 µm in diameter (PM 2.5), nitrogen dioxide, and ozone can cause airway inflammation. Therefore, air pollution is associated with the onset of asthma and also with asthma exacerbations.
Long-term effect of air pollution are more insidious. In infants, air pollution can affect lung development and has been implicated in emphysema, in addition to asthma (2). In children, ozone and PM 2.5, has been associated with asthma-related changes in the airways (3). Air pollution has been linked to increased breast cancer, non-Hodgkin’s Lymphoma, increased risk of stroke, and lung cancer (4-7).
As pulmonologists, we are tasked with making recommendations to our patients during times of high air pollution indices. In times of high outdoor air pollution that exceed recommended levels, we make the following recommendations:
- Wear N95 masks when outside for a prolonged period of time (8).
- Stay indoors if possible and keep windows closed.
- Do not exercise outdoors.
- Keep indoor air clean:
- Use a HEPA filter indoors.
- Do not use gas stoves, if avoidable.
- Do not use wax candles.
- Auto-circulate air within the automobile.
- Stay hydrated with water.
- For those with asthma:
- Have all inhalers refilled prior to expected air quality alerts.
- Consider backup prednisone, in case of need.
The most vulnerable populations are the following:
- Aging population within diminishing immune system capacity
- Infants and children with developing lungs
- Immunocompromised individuals
- Pets
Patients and providers can access AirNow.gov, source that can be used to explore neighboring air quality. The U.S. Air Quality Index (AQI) is a color-coded index designed to communicate whether air quality is healthy. When the air quality is green, air quality is satisfactory and air pollution is little or no risk. When the air quality is yellow, orange, and red, there is increased risk to people with asthma. For purple and maroon air quality colors, the risk of health effects is increased for everyone.
With awareness of local air quality alerts and appropriate preparedness, people can successfully manage their asthma in partnership with their asthma providers.
1. Guarnieri M, Balmes JR. Outdoor air pollution and asthma. Lancet 2014; 383: 1581-1592.
2. Wang M, Aaron CP, Madrigano J, Hoffman EA, Angelini E, Yang J, Laine A, Vetterli TM, Kinney PL, Sampson PD, Sheppard LE, Szpiro AA, Adar SD, Kirwa K, Smith B, Lederer DJ, Diez-Roux AV, Vedal S, Kaufman JD, Barr RG. Association Between Long-term Exposure to Ambient Air Pollution and Change in Quantitatively Assessed Emphysema and Lung Function. JAMA 2019; 322: 546-556.
3. Altman MC, Kattan M, O'Connor GT, Murphy RC, Whalen E, LeBeau P, Calatroni A, Gill MA, Gruchalla RS, Liu AH, Lovinsky-Desir S, Pongracic JA, Kercsmar CM, Khurana Hershey GK, Zoratti EM, Teach SJ, Bacharier LB, Wheatley LM, Sigelman SM, Gergen PJ, Togias A, Busse WW, Gern JE, Jackson DJ, National Institute of A, Infectious Disease's Inner City Asthma C. Associations between outdoor air pollutants and non-viral asthma exacerbations and airway inflammatory responses in children and adolescents living in urban areas in the USA: a retrospective secondary analysis. Lancet Planet Health 2023; 7: e33-e44.
4. Niehoff NM, Gammon MD, Keil AP, Nichols HB, Engel LS, Sandler DP, White AJ. Airborne mammary carcinogens and breast cancer risk in the Sister Study. Environ Int 2019; 130: 104897.
5. Smith MT, Jones RM, Smith AH. Benzene exposure and risk of non-Hodgkin lymphoma. Cancer Epidemiol Biomarkers Prev 2007; 16: 385-391.
6. Lin CK, Lin RT, Chen T, Zigler C, Wei Y, Christiani DC. A global perspective on coal-fired power plants and burden of lung cancer. Environ Health 2019; 18: 9.
7. Sun S, Stewart JD, Eliot MN, Yanosky JD, Liao D, Tinker LF, Eaton CB, Whitsel EA, Wellenius GA. Short-term exposure to air pollution and incidence of stroke in the Women's Health Initiative. Environ Int 2019; 132: 105065.
8. Carlsten C, Salvi S, Wong GWK, Chung KF. Personal strategies to minimise effects of air pollution on respiratory health: advice for providers, patients and the public. Eur Respir J 2020; 55.