Asthma diagnosis and treatmentThe role of air pollution in asthma and other pediatric morbidities
Section snippets
Sources and pathways of exposure
Outdoor air pollutants can come from many sources and include both gaseous and particulate pollution. Air pollution arises in 2 ways: as primary pollutants emitted directly out of exhaust pipes and stacks (including the gaseous pollutants NOx and SO2, as well as PM, such as soot), and as secondary pollutants formed from the primary pollutants in the atmosphere in the copresence of sunlight, moisture, or both (including O3 and secondary particles, such as sulfates). The dominant anthropogenic
Biologic bases for children's unique vulnerability to air pollution
Organogenesis of the lung begins in fetal life and is especially rapid in early childhood. The number of alveoli in the human lung increases from 24 million at birth to 257 million at the age of 4 years,4 and changes in the lung continue through adolescence.5 Exposure to air pollution alters the normal process of lung development, which is guided by a complex and precisely timed sequence of chemical messages.6 This suggests that air pollution might have a lasting effect on respiratory health.
The effects of individual pollutants on children's health
Air pollution episodes have provided the starkest evidence of their potential health consequences for children. A landmark event in the recognition of the disastrous effect of air pollution on child health occurred from December 1 through 5, 1952, in London. Trapped coal smoke in the Thames valley accumulated as a result of a stationary high-pressure cell accompanied by wind speeds near zero. Approximately 4000 excess deaths occurred in London that week,20 and excess deaths continued for weeks
Molecular mechanisms of air pollution toxicity
Exposure to outdoor air pollutants has been proven to induce molecular processes that could cause adverse fetal and perinatal outcomes. In one study, volunteers exposed to diesel particles for 1 hour had increases in peripheral white blood cell counts, as well as increased vascular cellular adhesion molecule 1 and intercellular adhesion molecule 1 levels in the lung epithelium. Increases in levels of C-reactive protein, an acute-phase inflammatory marker, have been associated with air pollution
Clinical implications
During the past 15 years, the incidence of asthma and the prevalence of severe asthma have increased in many countries, despite the availability of improved medications. A recent careful survey of schoolchildren in Hartford, Connecticut found that 19% had asthma.90 Some evidence suggests that air pollution might have contributed to the increasing prevalence of asthma.91, 92 Regardless of the role of air pollution as a contributing factor to the prevalence of asthma, the study by Gent et al24
Key steps for prevention of exposure
Infants and children are among the most susceptible to the important and diverse health effects of outdoor air pollution and provide a compelling need to move forward on efforts to ensure clean air for all. Currently, levels of O3 and PM air pollution remain unhealthy in many parts of the United States, and the current National Ambient Air Quality Standards might not protect the public adequately. The findings of Gent et al24 suggest that asthmatic children who use maintenance medication were
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2023, Pediatric Clinics of North AmericaAssociation of parent-reported health symptoms with indoor air quality in primary school buildings – The InAirQ study
2022, Building and Environment
This work was supported by a Superfund Basic Research Program grant to the Mount Sinai School of Medicine (NIEHS P42 ES07384) and by an Environmental Health Sciences Center of Excellence grant to the New York University School of Medicine (NIEHS ES00260).
Disclosure of potential conflicts of interest: L. Trasande—none disclosed. G.D. Thurston—none disclosed.