The COVID-19 pandemic has had far-reaching negative effects on population health. Yet one silver lining is global improvement in air quality, which is attributed to lockdowns and decreased vehicular traffic.
These changes in mobility, especially in the commercial and industry sectors, not only decreased air pollution but also may impact climate since the combustion process that creates air pollutants also creates greenhouse gases.
Emissions can be expected to rebound, however, as vaccination rates rise and stay-at-home orders and mandated business closures lift. Thus, it is an important time to advocate for policies to improve air quality, with co-benefits of decreasing air pollution and climate change.
The updated AAP policy statement Ambient Air Pollution: Health Hazards to Children provides a review for pediatric care providers on the intersection of air pollution with climate change and the impacts of air pollution on child health across the life course and even generations. It includes recommendations for pediatric practice, research, and regulation and policy to mitigate air pollution.
The policy from the Council on Environmental Health is available at http://doi.org/10.1542/peds.2021-051484 and will be published in the June issue of Pediatrics.
Air pollution sources, link to climate change
A range of sources contribute to poor ambient air quality, including vehicular traffic, coal-fired power plants, hydraulic fracturing, agricultural production and forest fires. Primary pollutants generated by combustion include fine airborne particulate matter 2.5 microns or less in diameter, sulfur dioxide, nitrogen oxide and secondary pollutants such as ozone formed in the atmosphere from precursor gases.
Air pollution and climate change are intertwined. Air pollutants and the greenhouse gases that drive climate change both arise from combustion. Additionally, climate change can exacerbate air pollution through increased temperatures, which promote ozone production.
Federal regulations under the Clean Air Act have improved air quality 70% since 1970. However, significant disparities by both race/ethnicity and socioeconomic status persist, and increases in pollutant levels in the past three years are of concern.
Growing evidence of impacts
Health outcomes from poorer air quality are mediated by oxidative stress, immune modulation, endocrine disruption, and genetic and epigenetic pathways across the life course and potentially generations. Fetuses, infants and children are particularly vulnerable due to rapid and sensitive developmental processes as well as higher intake of air per body weight in early life. Higher exposures in pregnancy increase risk of low birthweight among term infants and premature birth.
While asthma exacerbation was one of the first pediatric lung impacts to be characterized, the evidence now supports a role for air pollution in infant respiratory mortality, development of childhood asthma and reduced pediatric lung function growth.
New research is identifying concerning links between early life exposure and neurodevelopmental health, including cognitive function and risk of autism spectrum disorder. The cardiovascular toxicity and carcinogenicity of ambient air pollutants have been well-documented, and ongoing exposure to air pollution may lead to adult chronic disease such as cardiovascular disease and lung cancer.
Effective strategies
Air pollution mitigation is possible through both individual and policy changes.
On an individual level, use of public transportation, electric vehicles or walking or bicycling can be promoted. Individuals also can make outdoor activity decisions based on knowledge of local conditions through the Air Quality Index tool (see resources). At a policy level, continued strengthening of the Clean Air Act can build on decades of success in reducing air pollution from mobile and stationary sources.
Pediatricians are important advocates for reversing rollbacks of emissions limits from coal, gas and oil industries and promotion of clean and renewable energy. They also are trusted voices on policies that reduce school and child care exposure to traffic- derived air contaminants or other influential proximal sources. Pediatricians can use their collective voices to ensure consideration of pediatric and fetal stages of the life course in all program and regulatory standard review related to ambient air contaminants.
The burgeoning evidence base and the natural experiment of exposure reduction during the pandemic provide clear impetus for ongoing protection of child health through healthier ambient air.
Drs. Brumberg and Karr are lead authors of the policy statement and former members of the Council on Environmental Health Executive Committee. Dr. Karr also is co-director of the Northwest (region 10) Pediatric Environmental Health Specialty Unit.
