Study links specific outdoor air pollutants to asthma attacks in urban children

One study found that moderate levels of two outdoor air pollutants, ozone and fine particles, were linked to non-viral asthma attacks in children and adolescents living in low-income urban areas. The study also identified an association between exposure to the two pollutants and molecular changes in the children’s airways during non-viral asthma attacks, suggesting potential mechanisms for these effects. that attack. According to the investigators, this observational study is one of the first to link elevated levels of specific outdoor air pollutants in specific urban locations to marked changes. airways during asthma attacks not caused by respiratory viruses. The findings were published today in the journal Lancet Planet Health.

“The close association that this study demonstrates between specific air pollutants in children in impoverished urban communities and non-viral asthma attacks adds to the evidence that reducing air pollution will improve human health“, Hugh Auchincloss, MD, acting director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH.

The study was conducted by the Inner City Asthma Consortium under the leadership of Matthew C. Altman, MD, M.Phil., and Daniel J. Jackson, MD

Asthma is caused by chronic inflammation of the airways. During an asthma attack, the lining of the airways swells, the muscles around the airways contract, and the airways secrete more mucus, significantly narrowing the space for air to move in and out of the lungs. Children who live in low income Urban environments in the United States have a particularly high risk for asthma attacks. Asthma attacks caused by respiratory viral infections—a common trigger—have been studied extensively, but asthma attacks that occur independently of such infections have not.

In the current study, investigators examined the relationship between air pollution levels and asthma attacks that occurred in the absence of respiratory viruses in 208 children aged 6 to 17 years with asthma. prone to seizures and live in low-income neighborhoods in one in nine of the United States. cities. The researchers then confirmed the link they found between air pollution levels and non-viral asthma attacks in an independent group of 189 children ages 6 to 20 with asthma. Persistent asthma also lives in low-income neighborhoods in four US cities.

Investigators followed the children for up to two respiratory illnesses or about six months, whichever came first. Each disease is classified as viral or non-viral and involves a asthma attack or not. The researchers matched each disease with individual air quality index and air pollutant levels recorded by the Environmental Protection Agency in the relevant city on days. around the disease. The investigators then adjusted their data for city and season to reduce the impact of these variables on the results.

Scientists found that asthma attacks were not caused by viruses in nearly 30% of children, two to three times the rate seen in suburban children, according to previously published reports. These attacks are associated with local high levels of fine-grained and ozone in the outdoor air. The investigators linked changes in the expression of specific genomes that play a role in airway inflammation with elevated levels of these two pollutants by analyzing nasal cell samples obtained from children in respiratory diseases. Several gene expression patterns were identified that showed that only biological path may be associated with non-viral asthma attacks.

Based on the research findings, it will be important to develop and test different strategies to see if they prevent or reduce pollution-related asthma attacks in urban children. These strategies may include treatments designed to counteract the harmful effects of high levels of outdoor air pollutants on the airways. inflammatory response related to not virus asthma attackand devices to personally monitor local outdoor air pollution levels to inform asthma management.