Data Sources & Limitations

This page describes each data set presented in our Community Health Atlas, lists its data sources and discusses the limitations of the data.

Data Sources

Data Set/Description	Data Source(s)
Air emissions (estimated) The data set includes emissions estimates for four of the six criteria air pollutants (CAPs): particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide (included in the nitrogen oxides category). It also includes estimates for certain CAP precursors (ammonia, hydrochloric acid, nitrogen oxides and volatile organic compounds). Estimates for mercury, a hazardous air pollutant, are also provided. Data were obtained from the 2022 Emissions Modeling Platform (EMP), version 1. The 2022 EMP is based on the 2020 National Emissions Inventory (NEI; released in 2023) with updates to better represent the year 2022. Year 2026 emissions are projected estimates and reflect Federal and some state regulations that were effective as of April, 2024. NEI emissions estimates are based on estimates submitted by State, local and tribal (S/L/T) air agencies and information from EPA emissions programs, including the emissions trading program, Toxics Release Inventory (TRI), and data collected during rule development or compliance testing.	EPA and National Emissions Collaborative. Emissions Modeling Platform 2022 v. 1. Last accessed May 26, 2026. EPA. Technical Support Document (TSD): Preparation of Emissions Inventories for the 2022v1 North American Emissions Modeling Platform. May 2025. Last accessed May 29, 2026. EPA. 2020 National Emissions Inventory Technical Support Document: Introduction. March 2023. Last accessed May 29, 2026.
Risk Management Plan (RMP) facilities The Risk Management Program (RMP) rule requires facilities that use extremely hazardous, toxic, or flammable substances to develop and implement a Risk Management Plan. The facilities in this data set are those facilities in EPA's Facility Registry Service (FRS) that link to the Agency's Risk Management Plan (RMP) System.	EPA. EPA Facility Registry Service - Risk Management Plan (RMP). Accessed through Esri, ArcGIS.com. Last updated May 24, 2026.
Facilities with violations: Clean Air Act (CAA) Clean Water Act (CWA) Resource Conservation and Recovery Act (RCRA) This data set includes compliance and enforcement information (federal and state) for facilities with documented violations of the above-named environmental laws over the last 3 years as reflected in EPA's Enforcement and Compliance History Online (ECHO) database.	EPA. Enforcement and Compliance History Online (ECHO). Last accessed April 30, 2026.
Air monitoring data Air monitoring: All (2025) Particulate matter (PM10; PM2.5) Ozone (O3) Sulfur dioxide (SO2) Nitrogen dioxide (NO2) Carbon monoxide (CO) Lead (Pb) Summary air monitoring data for calendar year 2025 for individual regulatory air monitors. Includes data on exceedances of air quality standards (where applicable). The map layer "Air monitoring: All" enables users to display the locations and access data for all regulatory monitors in EPA's AirData database for the calendar year, while the remaining layers focus on individual criteria air pollutants and exceedances, if any, of National Ambient Air Quality Standards (NAAQS).	EPA. AirData. Pre-generated Data Files. Concentration by monitor. 2025. Accessed May 31, 2026.
Underground storage tanks (USTs) Contains location data for all underground storage tanks (USTs) in EPA's UST Finder database.	EPA. UST Finder Version 1.0. Last accessed June 3, 2026.
Air releases, lbs. Hazardous air pollutants OSHA carcinogens All chemicals Water releases, lbs. OSHA carcinogens, All chemicals Land releases, lbs. OSHA carcinogens All chemicals Total releases: air, water, land, lbs. Hazardous air pollutants OSHA carcinogens All chemicals Summary data on on-site toxic chemical releases for facilities that reported at least 10 pounds of releases to EPA's Toxics Release inventory (TRI)	EPA. TRI Explorer. Last accessed April 26, 2026.
Industrial/commercial infrastructure Airports Information on airport locations across the U.S., including data on type of ownership and whether leaded aviation fuel is available at each individual airport for public use.	U.S. Department of Transportation (USDOT)/Federal Aviation Administration. Aviation Facilities. Accessed through Esri, ArcGIS Hub. Last updated May 5, 2026. Last accessed May 31, 2026. U.S. Department of Transportation (USDOT)/Federal Aviation Administration. [Data Dictionary.] Last accessed May 31, 2026.
Industrial/commercial infrastructure Principal ports Location information for coastal, Great Lakes and internal ports in the U.S., and data on tonnage handled	U.S. Army Corps of Engineers, U.S. Department of Transportation and Esri Federal Data. Principal Ports. Accessed through Esri, ArcGIS.com. Last updated May 8, 2026. Last accessed May 31, 2026.
Industrial/commercial infrastructure Power plants Data on power plant locations, type (fossil fuel, clean renewables (geothermal, hydro, solar or wind), biomass, nuclear, batteries, other) and capacity in MW.	U.S. Geological Survey; Energy Information Administration. Accessed through FEMA Resilience Analysis and Planning Tool.
Industrial/commercial infrastructure Ethylene oxide commercial sterilizers Locations of commercial sterilizing facilities that use ethylene oxide (a powerful carcinogen). With links to detailed facility reports in EPA' Enforcement and Compliance History Online (ECHO) database.	EPA. Ethylene Oxide Commercial Sterilization Facilities, https://www.epa.gov/hazardous-air-pollutants-ethylene-oxide/ethylene-oxide-commercial-sterilization-facilities#tx, Last updated: May 25, 2025. Last accessed: August 18, 2025. [No longer online] EPA. Enforcement and Compliance History Online (ECHO). Detailed Facility Reports.
Industrial facilities Listed by sector	United States Environmental Protection Agency. (2026). TRI Explorer (2024 Dataset (released November 2025)) [Internet database]. Retrieved from https://enviro.epa.gov/triexplorer/, (April 26, 2026).
Community infrastructure Schools Location and legislative district information for schools nationwide	National Center for Education Statistics. School Geocodes & Geoassignments.
Community infrastructure Hospitals and medical centers Location information for hospitals and medical centers	U.S. Geological Survey. Hospitals, Medical Centers. Accessed through EsriFederal Data, ArcGIS Hub.
Community infrastructure Nursing homes Location, size and staffing information for nursing homes	FEMA National Integration Center (NIC) Technical Assistance Branch. Nursing Homes RAPT.
Community infrastructure Mobile home parks Location, status and size information for mobile home parks	FEMA National Integration Center (NIC) Technical Assistance Branch; Oak Ridge National Laboratory (ORNL); DHS Geospatial Management Office (GMO). Mobile Home Parks RAPT.
Community infrastructure Parks Location and size information for local, city, regional, county, state and national parks, forests and gardens.	TomTom and Esri. USA Parks. Updated May 19, 2026.
Community infrastructure Places of worship	FEMA National Integration Center Technical Assistance Branch. All Places of Worship _HiFLD Open_. [Data derived from Internal Revenue Service 501(c)3 organization records.] Accessed through ArcGIS Online. Last updated September 4, 2025. Last accessed June 7, 2026.
Drinking water Public water systems (PWS) with Safe Drinking Water Act (SDWA) violations This data set includes compliance and enforcement information (federal and state) for PWS with documented violations of the SDWA over the last 3 years as reflected in EPA's Enforcement and Compliance History Online (ECHO) database. It also contains information on water sources and population served. The map displays the service area for each included PWS.	EPA. Enforcement and Compliance History Online (ECHO). Last accessed April 30, 2026.
Drinking water PWS with unregulated contaminant detections (UCMR 5; 2023-2025) Monitoring results for public water systems (PWS) that reported detections of contaminants for which testing was required under EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5). UCMR 5 required public water systems to test for lithium and 29 per- and polyfluoroalkyl substances (PFAS, also known as "forever chemicals") in drinking water. The data set also contains information on water sources and population served. The map displays the service area for each included PWS.	EPA. Occurrence Data from the Unregulated Contaminant Monitoring Rule. UCMR 5 (2023-2025) Occurrence Data. Last accessed May 19, 2026.
Drinking water PWS with lead service lines Data on PWS with lead service lines, and/or lead connectors or galvanized pipe. Also includes information on water sources and population served.	EPA. Updated 7th Drinking Water Infrastructure Needs Survey and Assessment (DWINSA). EPA. Service Line Inventory.
Percent impaired watershed area (census tracts)	Agency for Toxic Substances and Disease Registry (ATSDR), Centers for Disease Control and Prevention, based on EPA Watershed Index Online (WSIO) data. Accessed through ATSDR's EJI Explorer. 2024 version. Last accessed July 7, 2026.
Environmental Justice Index + climate burden (census tracts)	Agency for Toxic Substances and Disease Registry (ATSDR), Centers for Disease Control and Prevention. EJI Explorer. 2024 version. Last accessed July 7, 2026.
Superfund sites Boundaries and site information for sites on the National Priorities List (NPL).	EPA. NPL Superfund Site Boundaries. Last accessed 4/26/2026.
Congressional districts: Health and socioeconomic profile	Sources by category: Percent of adults with current asthma, lifetime prevalence of cancer and crude prevalence of other health conditions among adults (used to estimate the number of adults with current asthma, number adults ever diagnosed with cancer (other than skin cancer), and number of adults experiencing high blood pressure, coronary heart disease, COPD, diabetes, stroke, frequent physical distress, self-reported poor health status, or disability): Centers for Disease Control and Prevention. PLACES: Local Data for Better Health, Census Tract Data 2024 release. Spending per capita on asthma and cancer treatment by county (used to estimate annual costs for asthma treatment and cancer treatment costs for adults ever diagnosed with cancer, excluding skin cancer): Institute for Health Metrics and Evaluation (IHME). United States Health Care Spending by Health Condition and County 2010-2019. Seattle, United States of America: Institute for Health Metrics and Evaluation (IHME), 2025. Obtained by request. Thanks to Dr. Joseph Dieleman and Mr. Drew DeJarnatt. (Resulting estimates have been adjusted for inflation to 2025 dollars.) Estimated lost work or school days and incremental indirect costs per person per year due to missed work or school days (productivity costs) caused by asthma: Estimated based on CDC crude prevalence data (see above) and: Song HJ, Blake KV, Wilson DL, Winterstein AG, Park H. Medical Costs and Productivity Loss Due to Mild, Moderate, and Severe Asthma in the United States. J Asthma Allergy. 2020 Oct 29;13:545-555. doi: 10.2147/JAA.S272681. PMID: 33149626; PMCID: PMC7605920. Access to health care, socioeconomic and demographic data: U.S. Census. Decennial Census, 2020. U.S. Census. American Community Survey, 2023. CDC. National Health Interview Survey, 2024. CDC. PLACES: Local Data for Better Health, Census Tract Data 2024 release. Congressional district boundaries: U.S. Department of Transportation, Bureau of Transportation Statistics. Congressional Districts. ArcGIS Hub. Census tract boundaries: U.S. Census Bureau. Cartographic Boundary Files. Inflation rates (used to adjust monetary figures to 2025 dollars): U.S. Bureau of Labor Statistics. CPI Inflation Calculator. Other: Aggregation of census tract- and county-level data to congressional districts performed using: ArcGIS Pro 3.6.4; Esri (2025).
Health burdens: Cancer This is a subset of the Congressional districts: Health and socioeconomic profile data set that enables the user to visualize lifetime prevalence of cancer (except skin cancer) by congressional district and obtain estimated treatment cost data for persons ever diagnosed with cancer in each district	See data sources for Congressional districts: Health and socioeconomic profile, above
Health burdens: Asthma This is a subset of the Congressional districts: Health and socioeconomic profile data set that enables the user to visualize prevalence of current asthma among adults by congressional district and obtain estimated productivity cost and treatment cost data	See data sources for Congressional districts: Health and socioeconomic profile, above
Elevated blood lead levels in children (county level)	CDC. Childhood Blood Lead Surveillance: State Data (except as noted below). County-level data not available through the CDC was obtained from the following sources: Arizona: Arizona Department of Health Services. Arizona 2022 Annual Report Blood Lead Surveillance; Childhood Lead Poisoning Prevention Program. Indiana: Indiana Department of Health. 2024 Childhood Lead Surveillance Report . Michigan: Department of Health and Human Services. Lead Exposure - Children . Minnesota: Minnesota Department of Health. 2024 Blood Lead Surveillance Report. Nevada: Nevada Institute for Children's Health Research and Policy; Nevada Childhood Lead Poisoning Prevention Program. Nevada Childhood Blood Lead Data 2022-2023 Annual Report. Ohio: DataOhio. Blood Lead Testing Public (2016-Present). Pennsylvania: Pennsylvania Department of Health. 2023 Childhood Lead Surveillance Annual Report. April 2026. South Dakota: South Dakota Department of Health. 2023 Blood Lead Annual Report. Texas: Texas Health and Human Services. Blood Lead Testing and Blood Lead Levels (BLL) ≥ 3.5µg/dl in Texas Children, Under 6 years of age, by County, 2023. Washington: Washington State Department of Health. Data Portal. Missing or suppressed data: Data for Arkansas, Idaho, Maine, Massachusetts, Minnesota, Montana, North Dakota, Rhode Island, Utah, Vermont and Wyoming are not included. Some of these states have not publicly released the relevant data, use a higher blood lead level reporting threshold than the CDC, release data for a smaller age cohort (for example, 0-2 years old) or do not report data by county. Even in states that have published their data, data for some counties may not be available or may have been suppressed for confidentiality reasons. This usually occurs when there is only a small number of children who have been tested or who have elevated blood lead levels (typically five children or fewer).
Heat and Health Index (ZIP codes)	Agency for Toxic Substances and Disease Registry (ATSDR). Heat & Health Index. Last accessed June 10, 2026. ATSDR. Heat & Health Index (HHI). [Fact sheet.] Last accessed June 12, 2026.
Natural hazards (National Risk Index): Drought, annualized frequency	FEMA. National Risk Index Annualized Frequency Drought. National Risk Index Version: March 2023 (1.19.0).
Natural hazards (National Risk Index): Inland flooding Coastal flooding Hurricane Tornado Wildfire Earthquake Tsunami	FEMA. Resilience Analysis and Planning Too l. FEMA. National Risk Index Data Technical Documentation. December 2025 - v1.20.

Data Limitations

Data in the Community Health Atlas are sourced from government and academic sources and mapping technology providers. Its accuracy is dependent on the completeness and accuracy of the original data sources. In addition, there is a lag time between the occurrence of environmental events, reporting deadlines, and the publication of the resulting data by EPA and other agencies. The Community Health Atlas will be regularly updated, but there may also be a lag between the publication of new data and updates to the tool.

Notes on Specific Data Sets

Air Emissions (Estimated)

The emissions data contained in EPA's Emissions Modeling Platform (EMP) were developed based on the 2020 National Emissions Inventory (NEI). While these emissions figures are the product of advanced, science-based models, they are estimates rather than direct measurements. [MAPPING TOOL NAME] only includes data for those sources for which geographic coordinates are available in the EMP. Other sources for which name and location data were not present-beyond a county name-are not displayed on the map. For this reason, nonpoint sources in the EMP data set are not mapped.

Risk Management Plan (RMP) Facilities

This data set is comprised of facilities in EPA's Risk Management Plan (RMP) System. Facilities required to develop and submit RMPs are those that produce, use or store extremely hazardous, toxic, or flammable in amounts exceeding a certain threshold. Since the amounts of these substances in use at any one facility are subject to change, there may be facilities listed in the RMP system that are no longer required to have RMPs.

EPA does not have a public database where RMPs can be downloaded but it provides information on how to obtain RMPs for individual facilities.

Facilities with Violations (including public water systems with SDWA violations)

Data on facilities with violations of major environmental laws (Clean Air Act, Clean Water Act, Resource Conservation and Recovery Act and the Safe Drinking Water Act) have been obtained from EPA's Enforcement and Compliance History Online (ECHO) database. ECHO contains compliance, inspection, and enforcement records for regulated facilities reported by EPA and state, local, and tribal environmental agencies. Although ECHO is the most comprehensive EPA public database for such information, facilities may incur violations that are not documented in ECHO.

Violations may remain unrecorded due to inadequate monitoring and reporting by regulated entities, insufficient inspection frequency, the timing of inspections not coinciding with periods of noncompliance, and/or inaccurate or delayed reporting of violations to ECHO by the agencies of jurisdiction. In some cases, data problems may result in facilities being erroneously classified as noncompliant in ECHO. EPA works with states to resolve data inaccuracies. For the latest flags concerning data issues, please refer to ECHO.

Air monitoring data

This data set references data captured by all regulatory air monitors contained in EPA's AirData system. The calendar year summary data-including the number of exceedances of air quality standards-were developed by EPA. Keep in mind that many areas lack regulatory monitors. Where monitors are present, their sampling data tends to be highly accurate for their exact location but is not necessarily representative of wider areas. This may result in local pollution hotspots not being detected. Furthermore, air monitors do not necessarily sample for all the chemicals that are relevant in a given location.

Underground storage tanks

Toxic releases (air, water, land, total on-site releases)

Data are drawn from EPA's Toxic Release Inventory (TRI). TRI contains toxic release data reported to EPA by facilities. Although reporting facilities sometimes determine their release amounts based on monitoring data or mass balances, in other cases they calculate these amounts based on emission factors. Not all facilities are required to report to the TRI. Whether a facility is required to report depends on its industrial classification, whether it manufactures, processes, or uses TRI-listed chemicals in excess of applicable thresholds, and whether it has 10 or more full-time employees (or the equivalent).

Ethylene oxide (EtO) commercial sterilizers

The EPA is no longer maintaining a public list of EtO sterilizers, and the list from which our data were sourced in 2025 is no longer available through the EPA website. Although efforts are made to maintain the accuracy of the data displayed by the Cumulative Impacts Mapping Tool, the current lack of public reporting on the location and operation of these facilities may lead to inaccuracies.

Hospitals/medical centers, nursing homes, mobile home parks

PWS with unregulated contaminant detections

The Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) required public water systems to test for lithium and certain PFAS chemicals only. The absence of other unregulated chemicals from the data should not be interpreted as evidence that they are not present in drinking water.

Lithium is a naturally occurring element that can cause kidney and nervous system damage at high levels. Per- and polyfluoroalkyl substances (PFAS, also known as "forever chemicals") are synthetic chemicals used in various industrial processes and the manufacture of many consumer products. They take a long time to break down in the environment. Exposure to PFAS is associated with health effects including reproductive problems, developmental delays in children, certain cancers and other harms. There are thousands of PFAS chemicals in use; UCMR 5 required testing for 29 of them. UCMR 5 testing took place from 2022 to 2025.

Since the list of UCMR 5 chemicals was developed, EPA established Maximum Contaminant Levels for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) but compliance deadlines, initially set for 2029, have been postponed to 2031. In 2025 EPA announced it would rescind limits for four other PFAS chemicals that had been issued in 2024.

PWS with lead service lines

The data rely on EPA's Updated 7th Drinking Water Infrastructure Needs Survey and Assessment (DWINSA) and its Service Line Inventory. Both rely on data submitted by public water systems. Some water systems lack information on the composition of at least a portion of their service lines and connectors or did not report on their composition. The number of lines of unknown on unreported composition is noted if the data for each system. Systems whose service lines and connectors were all non-lead, or all of unknown or unreported composition have not been included on the map.

Congressional districts: Health and socioeconomic profile

Socioeconomic and demographic data were obtained from the 2020 Census and the 2023 American Community survey and apportioned to congressional districts using ArcGIS Pro 3.6.4 (Esri, 2025). Census tracts may extend across more than one congressional district. Although the process of apportioning the data accounts for this, since populations may not be evenly distributed some degree of error may be present in the resulting estimates.

Data for per capita spending by county for asthma and cancer treatment was obtained from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington (special thanks to Dr. Joseph Dieleman and Mr. Drew DeJarnatt). The data represent asthma and cancer treatment expenditures by type of care for the year 2019. They include expenditures by the following types of payers: Medicare, Medicaid, private insurance, and out-of-pocket payments. These figures were adjusted to 2025 dollars using the U.S. Bureau of Labor Statistics. CPI Inflation Calculator. Since health care costs in the U.S. tend to rise faster than inflation, the cost estimates may underestimate actual costs.

Per capita expenditures for all types of care* were aggregated for each condition, asthma and cancer, within each county. The resulting county per capita spending figures for asthma and cancer were applied to all the census tracts within each county (census tract do not cut across county lines). For instance, if County A spent $100 per capita on asthma treatment, all census tracts were considered to be spending $100 per capita on asthma treatment. Since the costs of medical care may be unevenly distributed across a county, this may introduce some error.

For cancer, the IHME data set contained per capita spending by type of care by type of cancer in each county. These figures were summed to arrive at an estimate of total per capita spending on cancer treatment by county, excluding skin cancer. The per capita totals were then applied to each census tract within the county to produce estimates of total spending by census tract. Census tract data were apportioned to congressional districts to arrive at an estimate of annual spending by congressional district.

Asthma and cancer prevalence data were obtained from the CDC PLACES: Local Data for Better Health, Census Tract Data 2024 release, which is based on data for the year 2022. The CDC obtains PLACES data from the Behavioral Risk Factor Surveillance System (BRFSS), Census population data, and American Community Survey data. BRFSS data are self-reported data obtained through health surveys and are not confirmed by a medical professional for inclusion in the database. Census tract data was apportioned to congressional districts using ArcGIS Pro 3.6.4 (Esri, 2025).

Skin cancer was excluded from our estimates as it is also excluded from the Centers for Disease Control and Prevention cancer prevalence data in the PLACES database.

*Types of care: ambulatory care, emergency department care, home health care, hospital inpatient care, nursing facility care, and purchase of prescribed retail pharmaceuticals.

Health burdens: asthma and cancer

Elevated blood lead levels in children

County blood lead level data should not be used for state-to-state comparisons. Blood lead testing requirements vary by jurisdiction. Due to differences in testing requirements, rates of elevated blood lead data levels in children are typically not comparable between states.

Twelve states and the District of Columbia require universal lead testing for children, but age thresholds vary. Those that require universal testing are: CT, DC, DE, IA, LA, MA, ME, MD, NJ, NY, RI, VT and WI. Some states only require targeted testing of children deemed to be at increased risk while others do not require testing. (Sources: The Network for Public Health Law. 2019. State Lead Testing Policies for Children Not Enrolled in Medicaid: 50 State Compilation and CDC. Wisconsin Implements Universal Blood Lead Testing in 2024.)

The Medicaid program requires that all enrolled children be tested at the ages of 12 months and 24 months.

Data for Arkansas, Idaho, Maine, Massachusetts, Minnesota, Montana, North Dakota, Rhode Island, Utah, Vermont and Wyoming are not included. Some of these states have not publicly released the relevant data, use a higher blood lead level reporting threshold than the CDC, release data for a smaller age cohort (for example, 0-2 years old) or do not report data by county.

Even in states that have published their data, data for some counties may not be available or may have been suppressed for confidentiality reasons due to there being a very small number of children who were tested or who have elevated blood lead levels (typically five children or fewer).

Data Sources & Limitations

Data Sources

Air emissions (estimated)

Risk Management Plan (RMP) facilities

Facilities with violations:

Air monitoring data

Underground storage tanks (USTs)

Air releases, lbs.

Water releases, lbs.

Land releases, lbs.

Total releases: air, water, land, lbs.

Industrial/commercial infrastructure

Industrial/commercial infrastructure

Industrial/commercial infrastructure

Industrial/commercial infrastructure

Industrial facilities

Community infrastructure

Community infrastructure

Community infrastructure

Community infrastructure

Community infrastructure

Community infrastructure

Drinking water

Drinking water

Drinking water

Percent impaired watershed area (census tracts)

Environmental Justice Index + climate burden (census tracts)

Superfund sites

Congressional districts: Health and socioeconomic profile

Health burdens:

Health burdens:

Elevated blood lead levels in children (county level)

Heat and Health Index (ZIP codes)

Natural hazards (National Risk Index):

Natural hazards (National Risk Index):

Data Limitations

Notes on Specific Data Sets

Air Emissions (Estimated)

Risk Management Plan (RMP) Facilities

Facilities with Violations (including public water systems with SDWA violations)

Air monitoring data

Underground storage tanks

Toxic releases (air, water, land, total on-site releases)

Ethylene oxide (EtO) commercial sterilizers

Hospitals/medical centers, nursing homes, mobile home parks

PWS with unregulated contaminant detections

PWS with lead service lines

Congressional districts: Health and socioeconomic profile

Health burdens: asthma and cancer

Elevated blood lead levels in children

Heat and Health Index (HHI)

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