Air Pollution and Asthma

Mechanisms of Harm and Considerations for Clinical Interventions
Published:October 24, 2020DOI:
      There is global concern regarding the harmful impact of polluted air on the respiratory health of patients with asthma. Multiple epidemiologic studies have shown ongoing associations between high levels of air pollution and poor early life lung growth, development of allergic sensitization, development of asthma, airway inflammation, acutely impaired lung function, respiratory tract infections, and asthma exacerbations. However, studies have often yielded inconsistent findings, and not all studies have found significant associations; this may be related to both variations in statistical, measurement, and modeling methodologies between studies as well as differences in the concentrations and composition of air pollution globally. Overall, this variation in findings suggests we still do not fully understand the effects of ambient pollution on the lungs and on the evolution and exacerbation of airway diseases. There is clearly a need to augment epidemiologic studies with experimental studies to clarify the underlying mechanistic basis for the adverse responses reported and to identify the key gaseous and particle-related components within the complex air pollution mixture driving these outcomes. Some progress toward these aims has been made. This article reviews studies providing an improved understanding of causal pathways linking air pollution to asthma development and exacerbation. The article also considers potential strategies to reduce asthma morbidity and mortality through regulation and behavioral/pharmacologic interventions, including a consideration of pollutant avoidance strategies and antioxidant and/or vitamin D supplementation.

      Key Words


      DEP (diesel exhaust particle), NO2 (nitrogen dioxide), PM (particulate matter), PM2.5 (particulate matter with an aerodynamic diameter < 2.5 μm), T2 (type 2), Th2 (T helper lymphocyte type 2)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic and Personal
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to CHEST
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Robinson D.S.
        The role of the T cell in asthma.
        J Allergy Clin Immunol. 2010; 126: 1081-1091
        • Custovic A.
        • Belgrave D.
        • Lin L.
        • et al.
        Cytokine responses to rhinovirus and development of asthma, allergic sensitization, and respiratory infections during childhood.
        Am J Respir Crit Care Med. 2018; 197: 1265-1274
        • Contoli M.
        • Ito K.
        • Padovani A.
        • et al.
        Th2 cytokines impair innate immune responses to rhinovirus in respiratory epithelial cells.
        Allergy. 2015; 70: 910-920
        • Esquivel A.
        • Busse W.W.
        • Calatroni A.
        • et al.
        Effects of omalizumab on rhinovirus infections, illnesses, and exacerbations of asthma.
        Am J Respir Crit Care Med. 2017; 196: 985-992
        • Jackson D.J.
        • Makrinioti H.
        • Rana B.M.
        • et al.
        IL-33-dependent type 2 inflammation during rhinovirus-induced asthma exacerbations in vivo.
        Am J Respir Crit Care Med. 2014; 190: 1373-1382
        • Saglani S.
        • Bush A.
        The early-life origins of asthma.
        Curr Opin Allergy Clin Immunol. 2007; 7: 83-90
        • Glencross D.A.
        • Ho T.R.
        • Camiña N.
        • Hawrylowicz C.M.
        • Pfeffer P.E.
        Air pollution and its effects on the immune system.
        Free Radic Biol Med. 2020; 151: 56-68
        • Khreis H.
        • Kelly C.
        • Tate J.
        • Parslow R.
        • Lucas K.
        • Nieuwenhuijsen M.
        Exposure to traffic-related air pollution and risk of development of childhood asthma: a systematic review and meta-analysis.
        Environ Int. 2017; 100: 1-31
        • Jacquemin B.
        • Siroux V.
        • Sanchez M.
        • et al.
        Ambient air pollution and adult asthma incidence in six European cohorts (ESCAPE).
        Environ Health Perspect. 2015; 123: 613-621
        • Orellano P.
        • Quaranta N.
        • Reynoso J.
        • Balbi B.
        • Vasquez J.
        Effect of outdoor air pollution on asthma exacerbations in children and adults: systematic review and multilevel meta-analysis.
        Plos One. 2017; 12e0174050
        • Davis D.L.
        • Bell M.L.
        • Fletcher T.
        A look back at the London smog of 1952 and the half century since.
        Environ Health Perspect. 2002; 110: A734-A735
        • Pfeffer P.E.
        • Donaldson G.C.
        • Mackay A.J.
        • Wedzicha J.A.
        Increased chronic obstructive pulmonary disease exacerbations of likely viral etiology follow elevated ambient nitrogen oxides.
        Am J Respir Crit Care Med. 2019; 199: 581-591
        • Kelly F.J.
        • Fussell J.C.
        Air pollution and public health: emerging hazards and improved understanding of risk.
        Environ Geochem Health. 2015; 37: 631-649
        • Ghio A.J.
        • Carraway M.S.
        • Madden M.C.
        Composition of air pollution particles and oxidative stress in cells, tissues, and living systems.
        J Toxicol Environ Health B Crit Rev. 2012; 15: 1-21
        • Samoli E.
        • Atkinson R.W.
        • Analitis A.
        • et al.
        Differential health effects of short-term exposure to source-specific particles in London, UK.
        Environ Int. 2016; 97: 246-253
        • US Environmental Protection Agency
        Integrated Science Assessment (ISA) for Oxides of Nitrogen-Health Criteria (Final Report, 2016). EPA/600/R-15/068.
        Environmental Protection Agency, Washington, DC2016
        • Kelly F.
        • Anderson H.R.
        • Armstrong B.
        • et al.
        The impact of the congestion charging scheme on air quality in London. Part 1. Emissions modeling and analysis of air pollution measurements.
        Res Rep Health Eff Inst. 2011; 155: 5-71
        • de Barros Mendes Lopes T.
        • Groth E.E.
        • Veras M.
        • et al.
        Pre- and postnatal exposure of mice to concentrated urban PM2.5 decreases the number of alveoli and leads to altered lung function at an early stage of life.
        Environ Pollut. 2018; 241: 511-520
        • Gehring U.
        • Gruzieva O.
        • Agius R.M.
        • et al.
        Air pollution exposure and lung function in children: the ESCAPE project.
        Environ Health Perspect. 2013; 121: 1357-1364
        • Jedrychowski W.A.
        • Perera F.P.
        • Maugeri U.
        • et al.
        Effect of prenatal exposure to fine particulate matter on ventilatory lung function of preschool children of non-smoking mothers.
        Paediatr Perinat Epidemiol. 2010; 24: 492-501
        • Baiz N.
        • Slama R.
        • Bene M.C.
        • et al.
        Maternal exposure to air pollution before and during pregnancy related to changes in newborn's cord blood lymphocyte subpopulations. The EDEN study cohort.
        BMC Pregnancy Childbirth. 2011; 11: 87
        • Rice M.B.
        • Ljungman P.L.
        • Wilker E.H.
        • et al.
        Long-term exposure to traffic emissions and fine particulate matter and lung function decline in the Framingham heart study.
        Am J Respir Crit Care Med. 2015; 191: 656-664
        • de Nijs S.B.
        • Venekamp L.N.
        • Bel E.H.
        Adult-onset asthma: is it really different?.
        Eur Respir Rev. 2013; 22: 44-52
        • Diaz-Sanchez D.
        • Dotson A.R.
        • Takenaka H.
        • Saxon A.
        Diesel exhaust particles induce local IgE production in vivo and alter the pattern of IgE messenger RNA isoforms.
        J Clin Invest. 1994; 94: 1417-1425
        • Diaz-Sanchez D.
        • Garcia M.P.
        • Wang M.
        • Jyrala M.
        • Saxon A.
        Nasal challenge with diesel exhaust particles can induce sensitization to a neoallergen in the human mucosa.
        J Allergy Clin Immunol. 1999; 104: 1183-1188
        • Matthews N.C.
        • Faith A.
        • Pfeffer P.E.
        • Lu H.
        • Kelly F.J.
        • Hawrylowicz C.M.
        Urban particulate matter suppresses priming of Th1 cells by GM-CSF-activated human dendritic cells.
        Am J Respir Cell Mol Biol. 2014; 50: 281-291
        • Pfeffer P.E.
        • Lu H.
        • Mann E.H.
        • et al.
        Effects of vitamin D on inflammatory and oxidative stress responses of human bronchial epithelial cells exposed to particulate matter.
        PLoS One. 2018; 13e0200040
        • Bleck B.
        • Tse D.B.
        • Curotto de Lafaille M.A.
        • Zhang F.
        • Reibman J.
        Diesel exhaust particle-exposed human bronchial epithelial cells induce dendritic cell maturation and polarization via thymic stromal lymphopoietin.
        J Clin Immunol. 2008; 28: 147-156
        • Kido T.
        • Tamagawa E.
        • Bai N.
        • et al.
        Particulate matter induces translocation of IL-6 from the lung to the systemic circulation.
        Am J Respir Cell Mol Biol. 2011; 44: 197-204
        • Pasare C.
        • Medzhitov R.
        Toll pathway-dependent blockade of CD4+CD25+ T cell–mediated suppression by dendritic cells.
        Science. 2003; 299: 1033-1036
        • Nadeau K.
        • McDonald-Hyman C.
        • Noth E.M.
        • et al.
        Ambient air pollution impairs regulatory T-cell function in asthma.
        J Allergy Clin Immunol. 2010; 126: 845-852.e810
        • Han M.
        • Ji X.
        • Li G.
        • Sang N.
        NO2 inhalation enhances asthma susceptibility in a rat model.
        Environ Sci Pollut Res Int. 2017; 24: 27843-27854
        • Patel M.M.
        • Quinn J.W.
        • Jung K.H.
        • et al.
        Traffic density and stationary sources of air pollution associated with wheeze, asthma, and immunoglobulin E from birth to age 5 years among New York City children.
        Environ Res. 2011; 111: 1222-1229
        • Rage E.
        • Jacquemin B.
        • Nadif R.
        • et al.
        Total serum IgE levels are associated with ambient ozone concentration in asthmatic adults.
        Allergy. 2009; 64: 40-46
        • Brauer M.
        • Hoek G.
        • Smit H.A.
        • et al.
        Air pollution and development of asthma, allergy and infections in a birth cohort.
        Eur Respir J. 2007; 29: 879-888
        • Weir C.H.
        • Yeatts K.B.
        • Sarnat J.A.
        • et al.
        Nitrogen dioxide and allergic sensitization in the 2005-2006 National Health and Nutrition Examination Survey.
        Respir Med. 2013; 107: 1763-1772
        • Gruzieva O.
        • Gehring U.
        • Aalberse R.
        • et al.
        Meta-analysis of air pollution exposure association with allergic sensitization in European birth cohorts.
        J Allergy Clin Immunol. 2014; 133: 767-776.e767
        • Vimercati L.
        • Gatti M.F.
        • Baldassarre A.
        • et al.
        Occupational exposure to urban air pollution and allergic diseases.
        Int J Environ Res Public Health. 2015; 12: 12977-12987
        • Sordillo J.E.
        • Switkowski K.M.
        • Coull B.A.
        • et al.
        Relation of prenatal air pollutant and nutritional exposures with biomarkers of allergic disease in adolescence.
        Sci Rep. 2018; 8: 10578
        • Salvi S.
        • Blomberg A.
        • Rudell B.
        • et al.
        Acute inflammatory responses in the airways and peripheral blood after short-term exposure to diesel exhaust in healthy human volunteers.
        Am J Respir Crit Care Med. 1999; 159: 702-709
        • Wang E.
        • Wechsler M.E.
        • Tran T.N.
        • et al.
        Characterization of severe asthma worldwide: data from the International Severe Asthma Registry.
        Chest. 2019; 157: 790-804
        • Ramanathan Jr., M.
        • London Jr., N.R.
        • Tharakan A.
        • et al.
        Airborne particulate matter induces nonallergic eosinophilic sinonasal inflammation in mice.
        Am J Respir Cell Mol Biol. 2017; 57: 59-65
        • Chen R.
        • Qiao L.
        • Li H.
        • et al.
        Fine particulate matter constituents, nitric oxide synthase DNA methylation and exhaled nitric oxide.
        Environ Sci Technol. 2015; 49: 11859-11865
        • Brandt E.B.
        • Bolcas P.E.
        • Ruff B.P.
        • Khurana Hershey G.K.
        IL33 contributes to diesel pollution-mediated increase in experimental asthma severity.
        Allergy. 2020; 75: 2254-2266
        • Barnes P.J.
        Corticosteroid resistance in patients with asthma and chronic obstructive pulmonary disease.
        J Allergy Clin Immunol. 2013; 131: 636-645
        • Chambers E.S.
        • Nanzer A.M.
        • Pfeffer P.E.
        • et al.
        Distinct endotypes of steroid-resistant asthma characterized by IL-17A and IFN-gamma immunophenotypes: potential benefits of calcitriol.
        J Allergy Clin Immunol. 2015; 136: 628-637
        • Pfeffer P.E.
        • Hawrylowicz C.M.
        Vitamin D in asthma: mechanisms of action and considerations for clinical trials.
        Chest. 2018; 153: 1229-1239
        • Matthews N.C.
        • Pfeffer P.E.
        • Mann E.H.
        • et al.
        Urban particulate matter-activated human dendritic cells induce the expansion of potent inflammatory Th1, Th2 and Th17 effector cells.
        Am J Respir Cell Mol Biol. 2016; 54: 250-262
        • Brandt E.B.
        • Kovacic M.B.
        • Lee G.B.
        • et al.
        Diesel exhaust particle induction of IL-17A contributes to severe asthma.
        J Allergy Clin Immunol. 2013; 132: 1194-1204
        • Salvi S.S.
        • Nordenhall C.
        • Blomberg A.
        • et al.
        Acute exposure to diesel exhaust increases IL-8 and GRO-∝ production in healthy human airways.
        Am J Respir Crit Care Med. 2000; 161: 550-557
        • Wooding D.J.
        • Ryu M.H.
        • Li H.
        • et al.
        Acute air pollution exposure alters neutrophils in never-smokers and at-risk humans.
        Eur Respir J. 2020; 55: 1901495
        • Stenfors N.
        • Nordenhäll C.
        • Salvi S.S.
        • et al.
        Different airway inflammatory responses in asthmatic and healthy humans exposed to diesel.
        Eur Respir J. 2004; 23: 82-86
        • McCreanor J.
        • Cullinan P.
        • Nieuwenhuijsen M.N.
        • et al.
        Respiratory effects of exposure to diesel traffic in persons with asthma.
        N Engl J Med. 2007; 357: 2348-2358
        • Busse W.W.
        • Lemanske R.F.
        • Gern J.E.
        Role of viral respiratory infections in asthma and asthma exacerbations.
        Lancet. 2010; 376: 826-834
        • Caraballo J.C.
        • Yshii C.
        • Westphal W.
        • Moninger T.
        • Comellas A.P.
        Ambient particulate matter affects occludin distribution and increases alveolar transepithelial electrical conductance.
        Respirology. 2011; 16: 340-349
        • Morrow P.E.
        Possible mechanisms to explain dust overloading of the lungs.
        Fundam Appl Toxicol. 1988; 10: 369-384
        • Kim H.J.
        • Barajas B.
        • Chan R.C.
        • Nel A.E.
        Glutathione depletion inhibits dendritic cell maturation and delayed-type hypersensitivity: implications for systemic disease and immunosenescence.
        J Allergy Clin Immunol. 2007; 119: 1225-1233
        • Pfeffer P.E.
        • Ho T.R.
        • Mann E.H.
        • et al.
        Urban particulate matter stimulation of human dendritic cells enhances priming of naive CD8 T lymphocytes.
        Immunology. 2018; 153: 502-512
        • Horne B.D.
        • Joy E.A.
        • Hofmann M.G.
        • et al.
        Short-term elevation of fine particulate matter air pollution and acute lower respiratory infection.
        Am J Respir Crit Care Med. 2018; 198: 759-766
        • Chauhan A.J.
        • Inskip H.M.
        • Linaker C.H.
        • et al.
        Personal exposure to nitrogen dioxide (NO2) and the severity of virus-induced asthma in children.
        Lancet. 2003; 361: 1939-1944
        • Missagia S.
        • Amaral C.A.S.D.
        • Jesus A.S.
        • et al.
        Evaluation of peak expiratory flow in adolescents and its association with inhalable particulate in a Brazilian medium-sized city.
        Rev Bras Epidemiol. 2018; 21e180009
        • Higgins B.G.
        • Francis H.C.
        • Yates C.J.
        • et al.
        Effects of air pollution on symptoms and peak expiratory flow measurements in subjects with obstructive airways disease.
        Thorax. 1995; 50: 149-155
        • Weinmayr G.
        • Romeo E.
        • De Sario M.
        • Weiland S.K.
        • Forastiere F.
        Short-term effects of PM10 and NO2 on respiratory health among children with asthma or asthma-like symptoms: a systematic review and meta-analysis.
        Environ Health Perspect. 2010; 118: 449-457
        • Hernandez-Cadena L.
        • Holguin F.
        • Barraza-Villarreal A.
        • Del Rio-Navarro B.E.
        • Sienra-Monge J.J.
        • Romieu I.
        Increased levels of outdoor air pollutants are associated with reduced bronchodilation in children with asthma.
        Chest. 2009; 136: 1529-1536
        • Robinson R.K.
        • Birrell M.A.
        • Adcock J.J.
        • et al.
        Mechanistic link between diesel exhaust particles and respiratory reflexes.
        J Allergy Clin Immunol. 2018; 141: 1074-1084
        • Laden F.
        • Schwartz J.
        • Speizer F.E.
        • Dockery D.W.
        Reduction in fine particulate air pollution and mortality: extended follow-up of the Harvard Six Cities study.
        Am J Respir Crit Care Med. 2006; 173: 667-672
        • Bennett J.E.
        • Tamura-Wicks H.
        • Parks R.M.
        • et al.
        Particulate matter air pollution and national and county life expectancy loss in the USA: a spatiotemporal analysis.
        PLoS Med. 2019; 16e1002856
        • Mudway I.S.
        • Dundas I.
        • Wood H.E.
        • et al.
        Impact of London's Low Emission Zone on air quality and children’s respiratory health: a sequential annual cross-sectional study.
        Lancet Public Health. 2019; 4: e28-e40
        • Gauderman W.J.
        • Urman R.
        • Avol E.
        • et al.
        Association of improved air quality with lung development in children.
        N Engl J Med. 2015; 372: 905-913
        • Morishita M.
        • Adar S.D.
        • D’Souza J.
        • et al.
        Effect of portable air filtration systems on personal exposure to fine particulate matter and blood pressure among residents in a low-income senior facility: a randomized clinical trial.
        JAMA Intern Med. 2018; 178: 1350-1357
        • Kapoor M.
        • Storrar W.
        • Balls L.
        • et al.
        Nocturnal temperature-controlled laminar airflow device for adults with severe allergic asthma: the LASER RCT.
        Health Technol Assess. 2019; 23: 1-140
        • Rider C.F.
        • Carlsten C.
        Air pollution and resistance to inhaled glucocorticoids: evidence, mechanisms and gaps to fill.
        Pharmacol Ther. 2019; 194: 1-21
        • Pfeffer P.E.
        • Mudway I.S.
        The impact of real-world particulate matter air pollution on the airways of susceptible individuals.
        Am J Respir Crit Care Med. 2018; 198: 1362-1363
        • O'Beirne S.L.
        • Shenoy S.A.
        • Salit J.
        • et al.
        Ambient pollution-related reprogramming of the human small airway epithelial transcriptome.
        Am J Respir Crit Care Med. 2018; 198: 1413-1422
        • Whyand T.
        • Hurst J.R.
        • Beckles M.
        • Caplin M.E.
        Pollution and respiratory disease: can diet or supplements help? A review.
        Respir Res. 2018; 19: 79
        • Carlsten C.
        • MacNutt M.J.
        • Zhang Z.
        • Sava F.
        • Pui M.M.
        Anti-oxidant N-acetylcysteine diminishes diesel exhaust-induced increased airway responsiveness in person with airway hyper-reactivity.
        Toxicol Sci. 2014; 139: 479-487
        • Tashakkor A.Y.
        • Chow K.S.
        • Carlsten C.
        Modification by antioxidant supplementation of changes in human lung function associated with air pollutant exposure: a systematic review.
        BMC Public Health. 2011; 11: 532
        • Sienra-Monge J.J.
        • Ramirez-Aguilar M.
        • Moreno-Macias H.
        • et al.
        Antioxidant supplementation and nasal inflammatory responses among young asthmatics exposed to high levels of ozone.
        Clin Exp Immunol. 2004; 138: 317-322
        • Mann E.H.
        • Ho T.R.
        • Pfeffer P.E.
        • et al.
        Vitamin D counteracts an IL-23-dependent IL-17A+ IFN-γ+ response driven by urban particulate matter.
        Am J Respir Cell Mol Biol. 2017; 57: 355-366
        • Jolliffe D.A.
        • Greenberg L.
        • Hooper R.L.
        • et al.
        Vitamin D supplementation to prevent asthma exacerbations: a systematic review and meta-analysis of individual participant data.
        Lancet Respir Med. 2017; 5: 881-890
        • Rosser F.
        • Brehm J.M.
        • Forno E.
        • et al.
        Proximity to a major road, vitamin D insufficiency, and severe asthma exacerbations in Puerto Rican children.
        Am J Respir Crit Care Med. 2014; 190: 1190-1192
        • Pfeffer P.E.
        Targeting the exposome: does correcting vitamin D deficiency have potential to treat and prevent asthma?.
        Expert Rev Clin Immunol. 2018; 14: 241-243