Air pollutants in low-income urban areas linked with youth asthma attacks: study

Source: By Gianna Melillo, The Hill • Posted: Sunday, January 8, 2023

Researchers were able to connect individual pollutants with certain changes in airway functions and gene expression during the attacks.

Car pollution.


Common air pollutants ozone and fine particulate matter are associated with nonviral asthma attacks among U.S. youth living in dense, low-income urban areas, new research shows.

Asthma attacks can be triggered by a viral infection or other factors like pollen, certain chemicals or exercise, according to the CDC.

In the current study, asthma attacks were triggered by a nonviral cause in nearly 30 percent of children, marking a total two to three times greater than the proportion of these attacks in nonurban children, authors wrote. The nonviral attacks were linked with higher levels of local outdoor ozone and fine particulate matter pollution.

The study, funded by the National Institutes of Health, also found exposure to the pollutants was linked with molecular changes in children’s airways during the attacks, providing a possible explanation for the attacks’ underlying mechanisms.

“​​The strong association this study demonstrates between specific air pollutants among children in impoverished urban communities and non-viral asthma attacks further augments the evidence that reducing air pollution would improve human health,” said Hugh Auchincloss, acting director of the National Institute of Allergy and Infectious Diseases, in a release.

Asthma’s severity and prevalence have increased alongside urbanization, researchers explained, while children living in urban settings tend to be at a greater risk for asthma compared with those in rural or suburban areas.

A total of 168 children between the ages of 6 and 17 were included in the analysis. All children were free of respiratory viruses but had attack-prone asthma. Participants also lived in low-income neighborhoods in one of nine U.S. cities.

Children were followed up with for up to two respiratory illnesses or around six months, whichever came first. The illnesses were matched with EPA air quality index values and individual pollutant levels recorded around the same time of the illnesses.

After analyzing the link between air pollutant levels and asthma attacks in these children, researchers validated the relationship using data from another group of 189 children between the ages of 6 and 20.

Investigators also assessed nasal cell samples from children collected during their illnesses. The samples showed a link between elevated levels of the two pollutants and changes in the expression of specific sets of genes that play a role in airway inflammation.

Future interventions to prevent or reduce pollutant-associated asthma attacks in at-risk children could include devices that monitor local outdoor air pollutant levels.

More research is needed to understand the underlying mechanisms of the association to better prevent and treat asthma in these patients, the authors wrote.

Air pollution in impoverished areas has also been linked with reduced cognitive abilities in children, though interventions like strategic planting around school playgrounds could help curb exposure among this vulnerable population.