Fairfax County, Virginia

Geo level: countyFIPS: 51059Last update: Jul 22, 2026

Map

PM2.5(µg/m³)

EPA AQS · 2023

mean: 8.7 µg/m³ · max: 16.2 µg/m³

County-level resolution. No sub-county variation available in current data. Classification: single county-level value (no quantile classification — one feature).

Exposure Layers

Choropleth layerPM2.5(EPA AQS, 2023)Food Access(USDA Food Access Research Atlas, 2023)Traffic Proximity(EPA EJScreen, 2023)

County-level value of PM2.5 for Fairfax County, Virginia
Area	PM2.5 (µg/m³)	Details
Fairfax County, Virginia	mean: 8.7 µg/m³; max: 16.2 µg/m³

Health Burden (vs State & National)

asthma — prevalence

Unit: percent | Source: CDC PLACES (2023)

Region9.1

State9.4

National8

Fairfax County, Virginia is below the state rate and above the national rate for this measure.

asthma — hospitalization_rate

Unit: per 10,000 population | Source: Virginia Department of Health, Environmental Public Health Tracking (2023)

Region3.8

State5.1

National4.9

95% CI: [3.1, 4.6]

coronary-artery-disease — prevalence

Unit: percent | Source: CDC PLACES (2023)

Region4.8

State6.1

National5.8

Model Feature Attributions (SHAP)

SHAP values describe how this model weighted each feature when producing its prediction on regional training data. They are not estimates of causal effect. A feature can carry high attribution because it correlates with variables the model does not observe.

traffic_proximitypositive attribution (mean SHAP: 0.310)
PM2.5positive attribution (mean SHAP: 0.240)
socioeconomic_indexnegative attribution (mean SHAP: -0.220)
green_spacenegative attribution (mean SHAP: -0.150)
healthcare_accessnegative attribution (mean SHAP: -0.100)

Model Card

Version: 1.0
Training cutoff: 2024-06-01
Features used: PM2.5, traffic_proximity, socioeconomic_index, green_space, healthcare_access

Full model card →

Educational Resources

Fairfax County Health Department— Community health services, data, and programs for Fairfax County residents
Northern Virginia Health District— Virginia Department of Health regional office serving Northern Virginia counties

Evidence & Limitations

These are aggregate county-level figures. Associations observed between county-level exposure and county-level prevalence do not establish that exposed individuals within the county are the affected individuals — this is the ecological fallacy.

Community estimates are population-level and do not imply individual risk. Model outputs have uncertainty; see model card for details.

Health statistics are derived from CDC PLACES model-based estimates at the county level. County-level averages may mask significant within-county variation across census tracts, particularly in a large and diverse county like Fairfax. Exposure layers are modeled or interpolated from monitoring stations; local spatial resolution is limited. Traffic proximity data from EJScreen reflects proximity to major roads, not individual exposure. Model predictions are trained on state/regional data and may not capture Fairfax-specific conditions such as data center growth, rapid transit development, and changing demographics.