Cystic Fibrosis (CF) is a devastating chronic pulmonary disease that continues to cause significant morbidity and mortality despite great advances in therapies. Hispanic children with CF have worse outcomes, including higher mortality and more severe pulmonary disease, than non-Hispanic white children with CF. It is not known why Hispanic children with CF have more severe disease as it is not explained by CFTR genetic severity, diagnosis age, or socioeconomic status. The health disparities have worsened, not improved, for Hispanic children with CF since the development of new disease-altering therapeutics, CFTR modulators. It is critical to determine what is contributing to lung disease severity in Hispanic children with CF. Non-genetic factors, including environmental exposures, are estimated to account for 50% of lung disease severity variability in CF. Air pollution exposure during early childhood is associated with lower pulmonary function in healthy children and severe lung disease in children with asthma. However, air pollution exposure is vastly understudied in other chronic pulmonary diseases of childhood, such as CF. Investigating air pollution exposure in CF may provide vital information about the drivers of health disparities in Hispanic children with CF and about the environmental exposures influencing lung disease severity across all children with CF. To investigate air pollution exposure in children with CF, the investigators have assembled a multidisciplinary team of international experts in air pollution exposure, CF lung disease, health disparities, and pulmonary microbiome. The investigators will use two phenomenally rich databases, the CF Foundation Patient Registry and the University of Washington Spatiotemporal Air Pollution Exposure Model, to investigate the first aim: 1A) To determine whether neighborhood-level ambient air pollution exposure during childhood differs between 1500 Hispanic and 8500 non-Hispanic white cwCF in the CF Foundation Patient Registry, and 1B) To determine if neighborhood-level ambient air pollution exposure is associated with lung disease severity in Hispanic and non-Hispanic white cwCF. Across six geographically diverse clinical research CF centers, the investigators will enroll 100 Hispanic and 100 non-Hispanic children with CF to investigate the following aims: 2) To assess differences in residential indoor and ambient air pollution exposures by ethnicity in 200 cwCF, as well as the association between such exposure and pulmonary function by ethnicity, 3) To investigate the association of indoor and ambient air pollution exposure on airway inflammation and microbiome diversity and composition in Hispanic and non-Hispanic white cwCF using metatranscriptomic RNA sequencing. The HEROIC-CF Study is poised to advance the knowledge of the effect of air pollution exposure on not only CF lung disease severity, but may be a model to understand environmental exposures on disease severity in other chronic pulmonary diseases of childhood.

Inclusion Criteria:

• Age 6 to 18 years old
• Hispanic of any race or non-Hispanic white
• Diagnosed with cystic fibrosis

Exclusion Criteria:

• Cannot perform spirometry
• Planning to move in next 12 months
• Spends <4 nights a week in one residence
• Active smoking in the home

Children with confirmed cystic fibrosis