Air Pollution and Children's Health

The World Health Organization estimates that 93 percent of children under 15 worldwide (about 1.8 billion kids) breathe air dirty enough to threaten their health and development. In 2016, polluted air contributed to roughly 600,000 child deaths from lower respiratory infections.

Why kids are more vulnerable

Children breathe more air per pound of body weight than adults. They spend more time outdoors, often during peak pollution hours, and they breathe faster during play. Their lungs, brains, and immune systems are still developing, so the same dose of pollution can do more damage than it would to a grown body.

Lungs start forming around four weeks in the womb and keep developing through the late teens. Pollution exposure during any part of that window can leave permanent deficits.

What the research shows

The Children's Health Study, run by USC over more than a decade, followed thousands of children in Southern California. Kids in higher-pollution communities had measurably smaller lungs and weaker lung function at age 18 than kids in cleaner communities. When pollution in those areas later dropped, lung-growth rates improved, showing the effect is reversible at the population level but not for kids who already aged out of development.

Other findings consistently linked to early-life air pollution exposure:

• Higher rates of asthma diagnosis and asthma attacks
• More ear infections and respiratory infections
• Lower scores on cognitive and developmental tests
• Greater risk of childhood obesity
• Higher long-term risk of cardiovascular disease in adulthood

Who is most at risk

• Infants and toddlers
• Children with asthma or other chronic respiratory conditions
• Kids living near highways, ports, factories, or wildfire-prone areas
• Children in lower-income communities, who tend to live closer to pollution sources

What you can do

Check the AQI before sending kids outside to play. The general rule: when AQI is over 100, children with asthma should stay indoors or limit time outside. Over 150, even healthy children should cut back on hard outdoor activity.

Indoors, a HEPA air purifier in the bedroom and main living area can substantially cut PM2.5 exposure. Avoid scented candles, incense, and indoor smoking. If you use a gas stove, run the range hood every time. NO2 from gas cooking is linked to higher pediatric asthma rates.

Walk routes matter too. Walking on quieter side streets instead of next to busy traffic can drop kids' pollution exposure by a meaningful amount, sometimes 30 percent or more depending on the route.

If your child has frequent cough, wheeze, or shortness of breath, ask a pediatrician about asthma screening. Catching it early helps protect long-term lung function.

Sources

• More than 90% of the world's children breathe toxic air every day, WHO
• Air pollution, UNICEF Children's Environmental Health Collaborative
• Air quality and respiratory health in children, European Respiratory Society / PMC
• Headliners: Air Pollution Impairs Lung Development in Children, NIH
• How does air quality affect the health of children and adolescents?, PMC
• Small Changes, Big Impact: Exposure to Air Pollution and Reduced Lung Function in Children, NIH