Rationale: Higher indoor particulate matter (PM) concentrations are linked with increased asthma morbidity. Dietary intake of fatty acids, also linked with asthma outcomes, may influence this relationship. Objectives: To determine the relationship between omega-3 and omega-6 fatty acid intake and pediatric asthma morbidity, and the association between fatty acid intake and strength of indoor, PM-related asthma symptoms, albuterol use, and systemic inflammation. Methods: Analyses included 135 children with asthma enrolled in the AsthmaDIET Study. At baseline, 3 months, and 6 months, data included: week-long average home indoor concentration of PM ≤2.5 μm in aerodynamic diameter and PM ≤10 μm in aerodynamic diameter, dietary intake of omega-3 and omega-6 fatty acids, daily symptoms, and peripheral blood leukocytes. Asthma severity and lung function were assessed at baseline. Multivariable regression models, adjusted for known confounders, were used to determine associations between each fatty acid and outcomes of interest, with interaction terms (fatty acids × PM) in longitudinal analyses. Measurements and Main Results: Higher omega-6 intake associated with increased odds of increased asthma severity (P = 0.02), and lower FEV₁/FVC ratio (P = 0.01). Higher omega-3 intake associated with reduced effect of indoor PM ≤2.5 μm in aerodynamic diameter on symptoms (P < 0.01), whereas higher omega-6 intake associated with amplified effect of indoor PM ≤2.5 μm in aerodynamic diameter on symptoms and circulating neutrophil percentage (P < 0.01). Conclusions: Omega-3 and omega-6 intake are associated with pediatric asthma morbidity and may modify the asthmatic response to indoor PM.

Asthma and iron deficiency are common conditions. Whether iron status affects the risk of asthma is unclear. To determine the relationship between iron status and asthma, lung function, and pulmonary inflammation. Relationships between measures of iron status (serum ferritin, serum soluble transferrin receptor (sTfR), and sTfR/log10ferritin (sTfR-F Index)) and asthma, lung function, and pulmonary inflammation were examined in women 20-49 years in the National Health and Nutrition Examination Survey. Logistic, linear, and quadratic regression models accounting for the survey design of NHANES were used to evaluate associations between iron status and asthma-related outcomes and were adjusted for race/ethnicity, age, smoking status, income, and BMI. Approximately 16% reported a lifetime history of asthma, 9% reported current asthma, and 5% reported a recent asthma episode/attack (n = 2906). Increased ferritin (iron stores) was associated with decreased odds of lifetime asthma, current asthma, and asthma attacks/episodes in the range of ferritin linearly correlated with iron stores (20-300ng/ml). The highest quintile of ferritin (>76 ng/ml) was also associated with a decreased odds of asthma. Ferritin levels were not associated with FEV1. Increased values of the sTfR-F Index and sTfR, indicating lower body iron and higher tissue iron need, respectively, were associated with decreased FEV1, but neither was associated with asthma. None of the iron indices were associated with FeNO. In US women, higher iron stores were inversely associated with asthma and lower body iron and higher tissue iron need were associated with lower lung function. Together, these findings suggest that iron status may play a role in asthma and lung function in US women.

Indoor sources of air pollution worsen indoor and outdoor air quality. Thus, identifying and reducing indoor pollutant sources would decrease both indoor and outdoor air pollution, benefit public health, and help address the climate crisis. As outdoor sources come under regulatory control, unregulated indoor sources become a rising percentage of the problem. This American Thoracic Society workshop was convened in 2022 to evaluate this increasing proportion of indoor contributions to outdoor air quality. The workshop was conducted by physicians and scientists, including atmospheric and aerosol scientists, environmental engineers, toxicologists, epidemiologists, regulatory policy experts, and pediatric and adult pulmonologists. Presentations and discussion sessions were centered on 1) the generation and migration of pollutants from indoors to outdoors, 2) the sources and circumstances representing the greatest threat, and 3) effective remedies to reduce the health burden of indoor sources of air pollution. The scope of the workshop was residential and commercial sources of indoor air pollution in the United States. Topics included wood burning, natural gas, cooking, evaporative volatile organic compounds, source apportionment, and regulatory policy. The workshop concluded that indoor sources of air pollution are significant contributors to outdoor air quality and that source control and filtration are the most effective measures to reduce indoor contributions to outdoor air. Interventions should prioritize environmental justice: Households of lower socioeconomic status have higher concentrations of indoor air pollutants from both indoor and outdoor sources. We identify research priorities, potential health benefits, and mitigation actions to consider (e.g., switching from natural gas to electric stoves and transitioning to scent-free consumer products). The workshop committee emphasizes the benefits of combustion-free homes and businesses and recommends economic, legislative, and education strategies aimed at achieving this goal.