Table 1:

Examples of Environmental Exposures and Potential Relevance to CF Outcomes

Exposure Domain†	Variables*	Findings/Potential Relevance
Geographic	Ambient air pollutants/allergens and proxies: Elemental carbon attributable to traffic (ECAT) NO2; total PM2.5 and its elemental components: Al, Cu, Fe, K, Mn, Pb, S, Si, V, Zn Allergens (outdoor) Distance from residence to airports, railroads, bodies of water, highway and interstate Public transportation routes (e.g., highway traffic intensity, length of bus route)	CF-specific: Increased exposure to air pollution associated with declining FEV1 and more frequent pulmonary exacerbations in CF (8) (9) PE frequency in CF is linked to close proximity to major roadways (10) Non-CF: Fine-scale PM2.5 estimates have less biased associations with outcome than regional estimates (11) Greater exposure to traffic pollution is linked to worse pulmonary outcomes in pediatric asthma (12)
	Climatology: Relative humidity Temperature Precipitation Wind speed and direction	CF-specific: Reduced FEV1 in warmer climates linked to CF respiratory pathogens (13)
Community	Neighborhood characteristics/stressors: Deprivation index, percentage of poverty, percentage of vacant housing, percentage on assisted income living, percentage with high school education, median income, percentage with no health insurance Population density, crime density, combined sewer overflow sites, housing infarctions, urban tree cover Vacant properties, managed and vouchered properties, management companies	CF-specific: Lower income is linked to higher CF mortality rate (14) Non-CF: Geocoded proxies of socioeconomic status can yield more accurate predictions of outcome than Medicaid insurance use (15)
	Household characteristics/stressors: Home images, value, age, other physical characteristics Secondhand smoke Allergens (indoor)	CF-specific: Secondhand smoke exposure corresponds to lower FEV1 in CF patients (16) Indoor allergens are associated with Aspergillus in CF (17)
	Extent of greenspace: Degree of land cover by category: impervious, tree canopy, agriculture, bare soil, grass/meadow, water Satellite-measured near-infrared and visible radiation	Non-CF: Increased greenspace mediates impact of air pollution on pulmonary outcomes in asthma (18), (19) Associations between urban residential greenness/greyness and respiratory disease are modified by region (20), correlates with allergy outcomes (21) and asthma (22)
Healthcare Access	Distance from residence to CF care centers Nearest healthcare facilities Insurance coverage of therapies (Medicaid)	CF-specific: More rapid FEV1 decline is associated with driving farther distance to CF center (23) Medicaid insurance use is prevalent in early rapid decline phenotype (24)

^*Not all variables are available at the same levels of geographic resolution and time.