Population & age
- Total population
- 18,034
- Median age
- 37.8
Richland County · Columbia, SC · Population 18,034
Columbia, SC (ZIP 29204) sits in Richland County within the Columbia metro area. The page draws on 2 federal data feeds retrieved Apr 27. Top health signal: High Blood Pressure comes in above the national average at 40.6%. NCES lists 17 schools serving the area, 17 non-charter. 10 colleges and universities serve the area, with median in-state tuition of $17,793. IRS data shows average household income (AGI) of $67,590, well above the ~$45K national average per return. FEMA has issued 26 federal disaster declarations affecting this ZIP since 1977 — a high-frequency exposure profile. Per USDA's Food Environment Atlas, 46.5% of residents in this county live more than 1 mile (urban) or 10 miles (rural) from the nearest supermarket — a deep food-access gap. South Carolina levies a graduated state income tax (top rate 6.20%); a household at the local median AGI of $67,590 would pay roughly $2,514/year before deductions. New residents arriving here predominantly come from Lexington County, SC (IRS SOI Migration, 2022-2023). Healthcare access and school options both run strong here, giving residents a wide menu of providers and enrollment choices nearby. Notable: median household income $48,074, fair market rent of $1,170 for a two-bedroom, and a typical home value of $190,175, up 1.4% over the past year. Every figure on this page links to its underlying federal dataset with a retrieval date so you can audit the freshness yourself.
Studio
$960
/month
1 Bed
$1,060
/month
2 Bed
$1,170
/month
3 Bed
$1,500
/month
4 Bed
$1,800
/month
HUD Fair Market Rents represent the 40th percentile of standard-quality rental housing in this area. FY2026 data.
$190,175
Zillow Home Value Index (ZHVI) · as of March 2026
+1.4%
vs. March 2025
+36.5%
vs. March 2021
Columbia, SC
Metropolitan statistical area
Source: Zillow Research, ZHVI All Homes (SFR, Condo/Co-op) Time Series (zillow.com/research/data). Zillow Home Value Index (ZHVI) is copyrighted by Zillow, Inc.
New housing units permitted
3,469
Across 2,258 permitted buildings. Total construction value: $624.5M.
Single-family
2,154
62% of total units
Multifamily (2+ unit)
1,315
38% of total units
Single-family value
$436.0M
construction value
Multifamily value
$188.5M
construction value
Based on county-level data (2024).
Source: U.S. Census Bureau Building Permits Survey (census.gov/construction/bps). Public domain. BPS reports annual residential building permits from local permit-issuing jurisdictions, aggregated to county. A permit reflects intent to build, not a completed unit — actual construction lags by 6-24 months for multifamily projects.
Tax returns filed
7,670
Average AGI
$67,590
Avg property tax
$240
EITC participation
23.7%
Income distribution
Avg mortgage interest
$462
Avg charitable contribution
$1,095
Avg capital gains
$3,130
Avg total income tax
—
Source: IRS Statistics of Income — Individual Income Tax Statistics by ZIP Code (irs.gov). Public domain. Dollar columns reported in thousands by the IRS; figures here display real dollars. Total ZCTA AGI for the area was $518.4M across all reported brackets.
Business establishments
558
Total employment
7,703
Annual payroll
$323.4M
Average annual pay
$41,984
Source: U.S. Census Bureau, ZIP Business Patterns (census.gov). Public domain. ZBP covers establishments with paid employees; Census suppresses employment and payroll values when fewer employers operate in a ZIP than would protect their confidentiality.
Average annual pay
$62,784
Average weekly wage
$1,207
Total employment
227,771
Total establishments
12,736
That is roughly 4% below the US national average of $65,470 per worker.
Source: U.S. Bureau of Labor Statistics, Quarterly Census of Employment and Wages (bls.gov/cew). Public domain. QCEW is derived from state unemployment-insurance filings and covers ~95% of US jobs. Figures are county-level totals assigned to ZIPs whose primary county matches; small-employer cells are suppressed by BLS to protect employer confidentiality.
Unemployment rate
4.3%
That is 0.3 percentage points above the US national unemployment rate of about 4.0%.
Labor force
208,207
Employed
199,189
Unemployed
9,018
Based on Richland County, SC data (2024).
Source: U.S. Bureau of Labor Statistics, Local Area Unemployment Statistics (bls.gov/lau). Public domain. LAUS publishes monthly and annual labor-force estimates for every US county. Figures are county-level totals assigned to ZIPs whose primary county matches.
FDIC-insured bank branches
5
Typical banking access
A standard suburban / mid-density branch count for this area.
Total deposits
$224.3M
across all branches in this ZIP
Distinct institutions
5
different banks operating here
Top banks by deposits in this ZIP
Based on FDIC-insured branch offices as of June 30, 2024.
Source: FDIC Summary of Deposits (fdic.gov). Annual June-30 snapshot of every FDIC-insured branch and the deposits booked there. Figures cover all institutions reporting a branch address in this ZIP.
Federally funded health-center sites
4
Multiple health-center sites
A handful of federally funded community health centers serve residents — typical of mid-density suburban and small-urban areas.
FQHC sites
4
federally qualified
Look-Alike sites
0
FQHC equivalents
Avg hours / week
43
across sites in this ZIP
Sites in this ZIP
+ 1 more site in this ZIP
Federally Qualified Health Centers (FQHCs) and Look-Alike sites provide primary care on a sliding-fee scale, regardless of ability to pay. Active sites only; data refreshed 2026.
Source: HRSA Bureau of Primary Health Care (data.hrsa.gov). Per-ZIP counts of active service-delivery sites operated by Health Center Program grantees and Look-Alike organizations.
Facilities located inside ZIP 29204 from CMS Provider Data. Star ratings reflect Overall Hospital Quality where applicable; “Not rated” means the facility didn't report enough measures to qualify.
Hospitals (1)
MUSC HEALTH COLUMBIA MEDICAL CENTER DOWNTOWN
2435 FOREST DRIVE, COLUMBIA, SC, 29204
Source: Centers for Medicare & Medicaid Services Provider Data (data.cms.gov). Public domain.
FTA tracks transit service at the urbanized-area level. Numbers below reflect the agencies and modes serving the area that contains this ZIP, not stop-level coverage.
Service status
Available
Columbia, SC
Reporting agencies
1
Largest: Central Midlands Regional Transportation Authority
Annual ridership
—
unlinked trips · 2024
Source: U.S. Federal Transit Administration, National Transit Database (transit.dot.gov). Public domain.
Public-library outlets
1
Single library outlet
One public-library outlet serves this ZIP — typical of suburban and small-town areas. Card holders also have full access to the rest of the system's branches.
Buildings
1
1 branch
Avg hours / week
61.5
across outlets in this ZIP
Avg square feet
7,350
per outlet
Outlets in this ZIP
Public libraries provide free WiFi, computer access, children's programming, job-seeking resources, and meeting space — community infrastructure beyond books. FY2023 outlet inventory from the federal Public Libraries Survey.
Source: Institute of Museum and Library Services (imls.gov). Per-ZIP counts of active public-library outlets — central buildings, branches, and bookmobiles — operated by federally reporting library systems.
Federally Declared Disasters
26
Date Range
1977–2026
Most Recent Declaration
SEVERE WINTER STORM
Winter Storm — declared January 23, 2026 (DR-3632)
Incident period: January 21, 2026 – January 27, 2026
Top Incident Types
Individual Assistance
2
Direct help to disaster survivors
Households Program
4
Housing & temporary lodging support
Public Assistance
25
Repair of public facilities & roads
Hazard Mitigation
9
Funding to reduce future disaster risk
FEMA declares disasters at the county level; counts here include every federally declared disaster touching any county that overlaps this ZIP. Statewide declarations and pre-1964 records without county granularity are excluded. Program flags reflect which FEMA assistance categories were activated (Individual Assistance, Households, Public Assistance, Hazard Mitigation). Source: fema.gov/openfema. Public domain.
30-year averages (1991-2020) from the nearest GHCN-D weather station. Temperature and precipitation values reflect typical annual conditions, not any single year.
Avg. temperature
66.5°F
54.4° – 78.7°
Annual precipitation
48.1"
Annual snowfall
0.2"
Heating · cooling days
2,015.7 · 2,594.6
Annual base 65°F
Nearest station: COLUMBIA UNIV OF SC, SC US, 2.9 miles from the centroid of Columbia, SC (ZIP 29204)
Source: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (ncei.noaa.gov). Public domain.
Median daily AQI
47
GoodPeak AQI (2024)
141
Unhealthy for Sensitive Groups
Primary pollutant
PM2.5
263 days as main pollutant
Days measured
366
Based on Richland County data (2024).
Source: U.S. Environmental Protection Agency, Air Quality System (epa.gov). Public domain. Only counties with EPA AQS monitoring stations appear here (~30% of US counties); rural ZIPs whose primary county has no monitor will not show this section.
Years of potential life lost (per 100K)
9,521
That is roughly 1,321 years per 100,000 above the national county median (~8,200).
Premature death is the headline composite outcome CHR reports — age-adjusted, all-cause, before age 75.
Fair or poor health
17%
of adults self-report
Poor physical health days
3.9
avg per adult per month
Poor mental health days
5.3
avg per adult per month
Uninsured
9.6%
of residents under 65
Primary care MDs
82
per 100,000 residents
Preventable hospital stays
2,044
per 100K Medicare enrollees
Food environment (0-10)
7.2
10 = best access & security
Exercise access
74%
residents near a facility
Flu vaccinated
52%
of Medicare enrollees
Low birth weight (under 2,500 g) accounts for 11.2% of live births in this county — an early-life health input that downstream outcomes track against.
Based on Richland data (2025 CHR release).
Source: County Health Rankings & Roadmaps, University of Wisconsin Population Health Institute (countyhealthrankings.org). Annual release. Underlying source datasets vary by measure (CDC BRFSS, NCHS Vital Statistics, AHA, USDA Food Environment Atlas, and others). Figures are county-level and assigned to every ZIP whose primary county matches.
Food access status
Limited food access for many residents
46.5% of Richland County, SC residents live more than 1 mile (urban) or 10 miles (rural) from the nearest supermarket.
Grocery stores
0.12
per 1,000 residents
Supercenters & clubs
0.02
per 1,000 residents
SNAP-authorized stores
0.85
accepting food benefits
Fast-food restaurants
0.79
per 1,000 residents
Among low-income residents, 17.0% are low-access — those without a supermarket within 1 mile (urban) or 10 miles (rural).
Per-1,000 figures show how many of each store type exist in Richland County, SC for every 1,000 residents. Higher grocery and supercenter density usually means easier access to fresh food; higher convenience-store-only density (with low grocery rate) often signals a food swamp.
Source: USDA Economic Research Service, Food Environment Atlas (ers.usda.gov). County-level metrics fanned to ZIP via the primary county in the Census ZCTA-county relationship file. Variable years differ per family (stores ~2020, low-access ~2019).
FBI publishes crime data at the county level. Numbers below cover the primary county that contains this ZIP. Rates are per 100,000 residents in the area covered by reporting agencies.
Violent crime rate
—
per 100K residents · 1,468 reports
Property crime rate
—
per 100K residents · 5,086 reports
Homicide
27
Robbery
140
Burglary
837
Vehicle theft
863
County-level data for Richland (2024)
Source: U.S. Federal Bureau of Investigation, Uniform Crime Reporting Program (cde.ucr.cjis.gov). Public domain. Coverage varies by reporting agency; areas with partial agency coverage may understate true crime totals.
Net migration (2022-2023)
▲+1,743 people
+591 households • +$30.7M net AGI flow
Moved in
17,485households
31,486 people • $1.0B AGI
Moved out
16,894households
29,743 people • $993.5M AGI
Where new residents came from
Where departing residents went
Incoming households reported an average AGI of $58,577 versus departing households' $58,807.
Source: U.S. Internal Revenue Service, Statistics of Income, Migration Data (irs.gov). Public domain. Migration is measured by year-over-year changes in the address on individual tax returns; figures are county-level totals attributed to ZIPs whose primary county matches. Foreign migration contributes to inflow/outflow totals but does not appear in the top-county lists. Small flows are suppressed by IRS to protect taxpayer confidentiality.
State-level rules that apply to every resident of ZIP 29204. Numbers reflect the most recent published year per source.
Income tax
6.20%
graduated · 2 brackets
Sales tax (combined)
7.49%
State 6.00% · avg local 1.49%
Property tax (effective)
0.50%
Median $1,602/year
Tax burden rank
13 of 50
9.20% of personal income
For ZIP 29204: At this ZIP's median AGI of $67,590, the estimated state income tax (before deductions) runs about $2,514 per year. Applied to this ZIP's typical home value of $190,175, that works out to roughly $944/year in property tax.
Program
Voluntary (private insurance framework)
Voluntary (private insurance framework)
SNAP eligibility
130% FPL
Broad-Based Categorical Eligibility (raises gross income limit above federal 130% floor). No asset test.
Sources: Tax Foundation (state tax rates & brackets), Bipartisan Policy Center (paid family leave), USDA FNS (SNAP categorical eligibility).
Other ZIPs in Columbia
Nearby ZIPs by distance
29206 (Forest Acres, 2.2 mi) · 29208 (Columbia, 2.7 mi) · 29205 (Columbia, 2.7 mi) · 29225 (Columbia, 2.9 mi) · 29201 (Columbia, 3.6 mi) · 29203 (Columbia, 5.5 mi)
Compare ZIP-level stats — population, schools, housing, climate — across nearby areas. Source: U.S. Census Bureau ZCTA basemap.
All data on this page is sourced from federal government datasets · Not AI-generated · Methodology
Crude prevalence estimates from CDC PLACES, derived from BRFSS small-area modeling. Population-level figures only.
36.5%
3.5pp above the 33.0% national rate.
40.6%
8.6pp above the 32.0% national rate.
22.9%
Tracks close to the 22.0% national rate.
81.7%
5.7pp above the 76.0% national rate.
12.6%
Tracks close to the 13.0% national rate.
15.8%
4.8pp above the 11.0% national rate.
17 schools serve this ZIP, including 17 non-charter.
| School | Type | Grades | Enrollment |
|---|---|---|---|
| A. C. Flora High | Public | 9–12 | 1,363 |
| W. G. Sanders Middle | Public | 6–8 | 570 |
| Burton Pack Elementary | Public | -1–5 | 413 |
| C. A. Johnson High | Public | 9–12 | 387 |
| Bradley Elementary | Public | -1–5 | 378 |
Showing top 5 by enrollment. 12 more schools serve this ZIP.
Schools listed from NCES Common Core of Data via the Urban Institute Education Data Portal.
Fresh.NCES CCD via Urban Institute EDP · Apr 27, 2026Colleges in this area
10
Median in-state tuition
$17,793
Median earnings (10 yr)
$33,162
Columbia, SC · 29204
Columbia, SC · 29204
Columbia, SC · 29208
Columbia, SC · 29203
Columbia, SC · 29203
Columbia, SC · 29210
Columbia, SC · 29203
Columbia, SC · 29223
Columbia, SC · 29210
Columbia, SC · 29209
Source: U.S. Department of Education College Scorecard (collegescorecard.ed.gov). Public domain data. Earnings figures reflect median earnings 10 years after entry for federally-aided students.
Columbia, SC (ZIP 29204) sits in Richland County within the Columbia metro area. The page draws on 2 federal data feeds retrieved Apr 27. Top health signal: High Blood Pressure comes in above the national average at 40.6%. NCES lists 17 schools serving the area, 17 non-charter. 10 colleges and universities serve the area, with median in-state tuition of $17,793. IRS data shows average household income (AGI) of $67,590, well above the ~$45K national average per return. FEMA has issued 26 federal disaster declarations affecting this ZIP since 1977 — a high-frequency exposure profile. Per USDA's Food Environment Atlas, 46.5% of residents in this county live more than 1 mile (urban) or 10 miles (rural) from the nearest supermarket — a deep food-access gap. South Carolina levies a graduated state income tax (top rate 6.20%); a household at the local median AGI of $67,590 would pay roughly $2,514/year before deductions. New residents arriving here predominantly come from Lexington County, SC (IRS SOI Migration, 2022-2023). Healthcare access and school options both run strong here, giving residents a wide menu of providers and enrollment choices nearby. Notable: median household income $48,074, fair market rent of $1,170 for a two-bedroom, and a typical home value of $190,175, up 1.4% over the past year. Every figure on this page links to its underlying federal dataset with a retrieval date so you can audit the freshness yourself.
These two readings tell a consistent story. Strong access numbers usually correlate with denser provider networks, and a high school count signals the population base that supports them. Reading them together: a household weighing this ZIP for a multi-year stay can expect both healthcare and education infrastructure to keep pace.
One concrete reading worth keeping: Depression prevalence sits near the national rate at 22.9%. Each figure on this page links to the original federal dataset with its retrieval date — this synthesis is a reading, not a substitute for the underlying records.
36.5%, which is 3.5 percentage points above the national average of 33.0% (CDC PLACES, retrieved Apr 24, 2026).
22.9%, which is 0.9 percentage points above the national average of 22.0% (CDC PLACES, retrieved Apr 24, 2026).
40.6%, which is 8.6 percentage points above the national average of 32.0% (CDC PLACES, retrieved Apr 24, 2026).
17 schools serve this ZIP, including 17 public schools (NCES CCD, retrieved Apr 27, 2026). No charter schools are listed in this ZIP by NCES CCD.
No charter schools are listed in ZIP 29204 by NCES CCD (retrieved Apr 27, 2026).
Yes, 3 high schools serve this ZIP: A. C. Flora High, C. A. Johnson High, Samuel A. Heyward Career And Technology Center. (NCES CCD, retrieved Apr 27, 2026).
18,034 people live in ZIP 29204, with a median age of 37.8 (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
$48,074 per year (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
In ZIP 29204, 61.5% of occupied housing units are owner-occupied and 38.5% are renter-occupied (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
In ZIP 29204, 6.8% of workers work from home. Public transit is used by 2.8% of commuters (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
20.3% of the population in ZIP 29204 lives below the federal poverty line (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
78.3% of households in ZIP 29204 have broadband internet access (Census ACS 5-Year 2022, retrieved Apr 30, 2026).
The typical home value in ZIP 29204 is $190,175, up 1.4% from a year ago (Zillow Home Value Index, retrieved May 1, 2026).
Home values are up 1.4% over the past year and up 36.5% over the past five years (Zillow Home Value Index, retrieved May 1, 2026).
The average Adjusted Gross Income reported on tax returns from ZIP 29204 (Columbia, SC) is $67,590 per return (IRS SOI Tax Year 2022, retrieved May 2, 2026).
Tax returns from ZIP 29204 report an average of $240 per return in real-estate tax deductions (IRS SOI Tax Year 2022, retrieved May 2, 2026).
4.7% of tax returns from ZIP 29204 (Columbia, SC) report Adjusted Gross Income of $200,000 or more (IRS SOI Tax Year 2022, retrieved May 2, 2026).
As of 2022, 558 business establishments operated in ZIP 29204 employing 7,703 workers (Census ZIP Business Patterns, retrieved May 3, 2026).
The average annual pay across all local establishments in ZIP 29204 is $41,984, based on Census ZIP Business Patterns 2022 data (retrieved May 3, 2026).
According to the CDC Social Vulnerability Index (2022), ZIP 29204 ranks in the 70th percentile nationally for social vulnerability — a high vulnerability profile (retrieved May 3, 2026).
Socioeconomic Status is the highest-scoring CDC SVI theme for ZIP 29204, ranking in the 76th percentile nationally (CDC/ATSDR Social Vulnerability Index 2022, retrieved May 3, 2026).
FEMA has recorded 26 federal disaster declarations affecting ZIP 29204 between 1977–2026 (FEMA OpenFEMA Disaster Declarations, retrieved May 3, 2026).
Hurricane is the most common federally declared disaster type affecting ZIP 29204, accounting for 15 of 26 declarations (58%, FEMA OpenFEMA, retrieved May 3, 2026).
The most recent FEMA disaster declaration affecting ZIP 29204 was "SEVERE WINTER STORM" — a winter storm declared in 2026 (DR-3632) (FEMA OpenFEMA, retrieved May 3, 2026).
10 colleges and universities are listed near ZIP 29204 by the U.S. Department of Education College Scorecard, including Benedict College, Allen University, and University Of South Carolina-Columbia (retrieved May 2, 2026).
Median in-state tuition across 10 nearby institutions is $17,793 (College Scorecard, retrieved May 2, 2026).
Graduates of nearby colleges earn a median of $33,162 ten years after entry (College Scorecard, retrieved May 2, 2026).
ZIP 29204 has an average annual temperature of 66.5°F and 48.1" of annual precipitation based on the COLUMBIA UNIV OF SC, SC US weather station 2.9 miles from the ZIP centroid (NOAA 1991–2020 Climate Normals, retrieved May 8, 2026).
Yes — ZIP 29204 is part of the Columbia, SC urbanized area, primarily served by Central Midlands Regional Transportation Authority (National Transit Database 2024, retrieved May 4, 2026).
1 hospital is located in ZIP 29204 1 is rated by CMS, with an average overall rating of 3.0 out of 5 stars (CMS Hospital Compare, 2024).
South Carolina has a graduated income tax with a top rate of 6.20%. Households at the local median AGI of $67,590 would pay roughly $2,514 in state income tax annually (estimated, before deductions). Combined sales tax: 7.49% (Tax Foundation 2025).
South Carolina runs an active paid family leave program offering up to — weeks of paid leave per year (Bipartisan Policy Center 2026).
This page covers health outcomes from CDC PLACES (40 metrics), school information from NCES CCD (17 schools), demographics from the Census ACS 5-Year (2022), home values from the Zillow Home Value Index, colleges from the U.S. Department of Education College Scorecard (10 institutions), income & tax statistics from the IRS SOI (Tax Year 2022), local business & employment from Census ZIP Business Patterns (2022), social vulnerability scores from the CDC/ATSDR SVI (2022), federal disaster declarations from FEMA OpenFEMA (26 on record), climate normals from NOAA NCEI (1991-2020), county-level crime data from the FBI Crime Data Explorer (2024), public transit coverage from the National Transit Database (2024), hospitals from CMS Hospital Compare, and state-level tax rates from the Tax Foundation. Data is refreshed on Mubboo's standard schedule.
Health data retrieved Apr 24, 2026 from CDC PLACES. School data retrieved Apr 27, 2026 from NCES CCD. Demographics retrieved Apr 30, 2026 from Census ACS 5-Year (2022). Home values retrieved May 1, 2026 from Zillow Research. College data retrieved May 2, 2026 from U.S. Dept of Education College Scorecard. Income & tax statistics retrieved May 2, 2026 from IRS SOI (Tax Year 2022). Business & employment retrieved May 3, 2026 from Census ZBP (2022). Social vulnerability scores retrieved May 3, 2026 from CDC/ATSDR SVI (2022). Federal disaster declarations retrieved May 3, 2026 from FEMA OpenFEMA (26 on record). Climate normals retrieved May 8, 2026 from NOAA NCEI (1991-2020). County-level crime data retrieved May 4, 2026 from the FBI Crime Data Explorer (2024). Transit coverage retrieved May 4, 2026 from the National Transit Database (2024). State-level tax rates retrieved 2026-05-05 15:58:22.284+00 from the Tax Foundation.
Other ZIPs in Columbia
Nearby ZIPs by distance
29206 (Forest Acres, 2.2 mi) · 29208 (Columbia, 2.7 mi) · 29205 (Columbia, 2.7 mi) · 29225 (Columbia, 2.9 mi) · 29201 (Columbia, 3.6 mi) · 29203 (Columbia, 5.5 mi)
Compare ZIP-level stats — population, schools, housing, climate — across nearby areas. Source: U.S. Census Bureau ZCTA basemap.
Have a specific question about ZIP 29204?
Ask Mubboo — launching Q4 2026.
Data refreshed via Mubboo's ETL pipeline; oldest source on this page retrieved Apr 24, 2026.
Social Vulnerability Index
Overall SVI
70th percentile
High Vulnerability
Based on 13 census tracts, population 17,453
Vulnerability Themes
Households Without Vehicle
1,004
Limited English Speakers
67
Persons with Disability
2,911
Without HS Diploma
1,271
Without Health Insurance
1,846
Adults Age 65+
3,524
The Social Vulnerability Index uses U.S. Census data to identify communities most at risk during public health emergencies and natural disasters. Higher percentiles indicate greater vulnerability. Tract-level scores are aggregated to this ZCTA via Census 2020 ZCTA→Tract crosswalk, weighted by land-area share. Source: atsdr.cdc.gov. Public domain.