Low Ozone Levels Negatively Affect Subsets of Adolescents With Asthma

African-American adolescents with persistent asthma who were on appropriate daily asthma controller therapies showed both decreased lung function and elevated blood lipid levels when exposed to short-term ozone levels below the 70 PPB National Ambient Air Quality Standard (NAAQS) set by the Environmental Protection Agency, according to a study published in The Journal of Allergy and Clinical Immunology.

Minorities living in urban, low-income housing often experience increased exposure to indoor and outdoor pollution, potentially increasing their risk for diseases like asthma, which can be induced by pollutants. Researchers examined the systemic and respiratory response of 23 African-American teenagers (ages 12 to 17) in Raleigh, North Carolina, to changes in ozone that dipped below the NAAQS 70 PPB (ClinicalTrials.gov Identifier: NCT01891630). All participants were patients at Immunology/Allergy and Pediatric Pulmonary clinics, and all used guidelines-based asthma controller therapies.

From August 2013 to October 2014, all 23 participants completed 6 weekly clinic study visits where spirometry was performed and blood was drawn. The analysis used the average daily ozone exposure concentrations for the day of clinic visits, as well as the 4 previous days. Reduced lung function measurements were associated with elevated ambient ozone concentrations, with a decrease of 2.7 points in the  percent predicted forced vital capacity (P =.02), and a decrease of 2.9 points in  the preceding 5-day moving average (P =.07). Increased ozone levels were also associated with increases in blood lipids of 5.56 mg/dL at lag 1 per IQR of ozone (P <.006), but no changes in very low-density lipoprotein or triglycerides.

The study investigators concluded that exposure to sub-NAAQS levels of ambient air ozone is associated with systemic and respiratory changes in African-American teenagers with asthma, with asthma controller therapies not protecting the adolescents from the pulmonary effects. They further noted that “this is the first report of systemic changes associated with short-term ozone exposure in adolescents, and will need to be confirmed in larger scale studies involving more diverse groups at high risk of exposure to ambient air pollution.”

Disclosures: This study was funded by 5T32GM086330, CR 83578501, the US Environmental Protection Agency, and the AAAI Foundation.

Reference

Hernandez ML, Dhingra R, Burbank AJ, et al. Low-level ozone has both respiratory & systemic effects in African-American adolescents with asthma despite asthma controller therapy [published online August 10, 2018]. J Allergy Clin Immunol. doi: 10.1016/j.jaci.2018.08.003.